PollyMobiles Rebuild

pollyp · Nov 18, 2024

My Consult diagnostic cable made by old Blazt tends to annoyingly freeze the laptop at random whilst datalogging with NissanDataScan

I thought it was electrical interference but I noticed that simply nudging the cable will disrupt the signal & freeze the screen, so there must be a loose/bad connection?

The old cable connector loosed dirty inside, probably dirty terminals so I cleaned the pins

Here's all the terminals on my 1998 consult connector

& close look at the Blazt USB Nissan Consult control board

Now it can datalog without freezing.
Went for a datalog drive to compair the current setup with the old runs

Subjectively I think she feels faster but it might be increased NVH

Comparing all the 2nd gear 3k-7k rpm pulls along the same slip road on all my videos treating it like a dyno pull, the data says all my N/A setups have exactly the same acceleration

New 4-1 mani with big exhaust pulls the same as my old 421 header with slim exhaust, & the previous oem mani that's been enlarged to 2.25" & even when I stripped the lighter interior

But comparing the datalog also told me the MAF is reading lower/worn/dirty, the new TPS can read higher, new loom has less voltage drop.
Resulting in higher injector duty & period = richer AFR = little more power
But the heavier big exhaust, subwoofer, brakes & wheels might have counteracted the higher HP?

Today I took a long gentle 60mph cruise on a chilly day to finally test if the removed PAS & smooth 4-1 manifold helped reduce some drag loss?
Answer is nope, she did the same 44-46mpg as before

Guess I'll reinstall the power steering cos it doesn't affect mpg and parking with manual rack & LSD has been an absolute pain lol

pollyp · Nov 22, 2024

Brought a BiggRed service kit on ebay for rebuilding the rear calipers with fresh rubber & pistons for £37

pollyp · Nov 29, 2024

2024-11-22 Peugeot 307 MOT

The old peugeot failed it's MOT after the handbrake cable snapped, tie-rod boot split & worn left ball-joint

So immediately went to eurocarparts, replaced the handbrake cable which was really easy peasy

Replaced the left tie rod end

I didn't feel any excess play on both lower ball-joints

hmm maybe they meant the original inner control arm bushings, which does look perished? so after swearing at rusty, badly placed & odd-sized fasteners, I got the arms off

new bushings

pressed the old ones out

press new bushes on

both arms mended after 6 hrs

went for a retest BUT guy said I replaced the wrong part!
the ball-joint still has lots of play. wtf he showed me and it's a tiny amount.
ok I'll replace it, thankfully he didn't charge the £10 retest once he spotted this

upright removed

yeah that left ball joint was slightly worn & loose

thankfully it was a smooth process to replace

it finally passed its MOT

pollyp · Nov 29, 2024

2024-11-29 Compare Turbo WG Actuators

The Turbotechnic S116 & spare GT1549 turbo both use the same size WG actuator but have different port layout, I was wondering if they have the same spec & can be swapped?

So I hooked it to a pressure tester, apply incremental pressure & measure the travel

Answer is no they're both different.
The larger S116 turbo (rated upto 12.3psi) uses a softer spring, opening more per PSI
whereas the smaller GT1549 turbo uses a harder spring, opening less per PSI

Both actuators would be applied with 2mm preload, meaning the WG doesn't start to crack open until boost gets over 6psi.
at 12.3psi the S116 WG opens by 6mm while the GT1549 WG only opens by 2.5mm

In other news, I added this rubber cover over the gear stick joint to reduce some road noise & dust

Also currently designing the boost pipe layouts

pollyp · Nov 30, 2024

It feels like the LSD preload has gone down recently cos it wheel spins a little bit more in the cold season, doesn't chatter as much and I can spin the wheel by hand with little resistance BUT the ramp does still engage / lock during right turns.

It's been 4 mths since fitting the LSD so good time to change the oil & see if it gets better

(note: yup changing the oil made the LSD plates feel little more 'grippier' once again).

CG13 gearbox takes 3L of oil.

oil mostly ok but hazy with debris

usual debris on the plug, may have grinded a gear recently

also replaced the wrong size regular manifold bolts with correct length stainless bolts

pollyp · Dec 3, 2024

2024-12-03 Service Peugeot 307 & Binding Caliper

The Peugeots rear caliper has been binding for the past few yrs, so I'll try refresh the old rubbers.
Brake line is seized on, so I'll just leave it attached & strip the caliper apart.

Yeah the piston seal has definately gone old, hard & had to peel it out the cylinder

easy enough to remove this handbrake mech so I'll have access to wirebrush the grooves clean

Also cleaned the piston mechanism

note: it was a little dirty/rusty within the self-adjuster plunger hole, so I cleaned it off plus cleared the 1.6mm oiling hole at the tip of the piston for oilng the dust boot

Rebuilt caliper now fully releasing/retracting the piston when foot or hand brake released, doesn't drag anymore

The battery has been struggling recently.
It holds 12.6v fine outside the car when I trickle charge it.
When left overnight with car locked, it struggles to start with just 12-12.3v
When running, it only gets 13.58v with a 60mV drop from alternator to battery +ve.

I think the alternator is worn out, unable to fully charge the battery upto 14v

Changed the oil filter after 12 mths

pollyp · Dec 6, 2024

2024-12-06 Rebuild Rear Brake Calipers

Time to overhaul the rear calipers because the dust boot was slightly torn

Ahh, this thin plate I welded over the damper top cup has now rusted away

It was just cheap thin untreated sheet steel, plus there were gaps at the sides where moisture could've seeped through and rusted inside out.
Another thing to repair soon

The rest of the arch (which was rusted treated, zinc primed, coated with epoxy primer and finally polyurethane topcoat since 2yrs ago) is still solid with no signs of rust coming through, so the tough coating is working

I should paint the same stuff under the sills & front arch when I repair it soon.

Both calipers removed

Note the damaged dust boot at the bottom where my pliers slipped when retracting the pistons

Both pistons are still ok & smooth

Managed to collect two sets of repair kits over the years for the rear Micra calipers & GTIR front calipers

Both kits from Brake-Caliper-Solutions and Bigg-Red feature very similar seals

The Bigg-Red kit came with additional new hollow-pistons & seals for the piston-plunger

The main difference between the kits is the handbrake swing-arm seal.
Big-Red has a thick tapered head similar to OEM whereas BrakeCaliperSolutions uses a shallow flat profile seal, which may not seal as good.

Left caliper stripped apart

Right caliper stripped apart

I spotted the left caliper handbrake-plunger (sits within the piston) has some rough pitting spots on the flat bearing surface,
which could cause the tiny thrust bearing to jam & affect how smoothly the handbrake mechanism self-adjusts.

Easy enough to machine smooth on lathe

The biggest issue is how badly corroded/pitted the drivers handbrake swingarm shaft is

That definately won't provide a good smooth seal to keep dirt out & may require welding/machining

Replacing the whole caliper just for that swing arm ain't worth it.

Checking clearances of the lathe, the big swing arm will foul the tool holder and using a parting tool with extremely long stick-out ain't gonna work

Marked the angle of the shaft relative to the swing-arm

Decided to machine the back-side of the shaft thinner

So that the shaft can be separated from the swing arm

Giving the lathe tool enough space to machine the shaft down to smooth clean steel

Next task is to weld a fresh layer steel onto the shaft, machine it down to a smooth dimension & attach it onto the swing arm

pollyp · Dec 7, 2024

Added some welds using the lathe.

Cardboard shield keeps spatter off the jaws.
It span abit too quickly so the weld wasn't consistant but after adding few mm it was easy enough to machine down to size

Machined down to 15.95mm with a fresh groove for the seal

Welded onto the swing arm

Shaft is now nice & smooth

Cleaned the bores

Right caliper uses a brass insert for the handbrake shaft

Whereas the left caliper uses a teflon insert

ps: the groove for the rubber seal to sit within is 2mm...

So when I tried fitting the Bigg-Red seal (left) it wouldn't sit properly cos the lower lip was too thick at 3.2mm
The flatter seal from BrakeCaliperSolutions (right) sat properly in the groove cos it was 2.0mm

Both calipers fully rebuilt

Installed, bled and working very smoothly with no binding at all

Can't be bothered to fix this minor rust hole while a storm is blasting here

Ducktape it for now lol

pollyp · Dec 11, 2024

2024-12-11 Peugeot 307 Check Alternator

The old peugeot has been struggling to hold enough battery voltage left over few days to crank the car, the battery only receives upto 13.5v when running.

Thinking maybe the alternator diode is wearing out, I began taking it out to check it.
Damn peugeot placing their bolts in such awquid tight spots facing the exhaust making access very difficult

Eventually managed to wriggle the 4 bolts out

Need to remove this little cover to access the regulator

Nice of peugeot to tigerseal the area

Peeled the tigerseal off to unbolt just the terminals

Couldn't risk peeling the tigerseal off the regulator & slip-ring cover cos it was risky, running out of daylight, so I reassembled with the cleaned up bits.

Now upon further testing, the alternator +ve to alternator casing actually does output the proper 14v (so it's working fine).
But the battery terminals only receive 13.58v with no load,
13.0v with high load,
0.06v drop from alternator +ve to battery +ve
and a massive 0.50v drop from alternator casing to battery -ve

So I think the grounding cable between the engine block and the battery -ve is to blame for the poor voltage, probably corroded from the rain dripping off the windscreen onto the battery area

pollyp · Dec 12, 2024

2024-12-12 Solved Peugeot Charging Issue

For the past few yrs the peugeot's been struggling to fully charge/hold power over few days.
Alternator was fine, outputting 14v but battery only receives 12.3-13.5v
Battery also holding charge fine for days once trickle charged & unplugged.

Positive lead has a normal 60mV drop
Negative lead has a huge 600mV drop, which might be the main fault caused by bad earth.

So I removed the -ve battery lead

It grounds the battery -ve to the gearbox casing & chassis earth circled, both of which are badly corroded

Wirebrushed all oxide off, greased all bolts, reassembled.

And now the battery receives a full 14.10v

Drops to 12.95v when literally all electronics are at max load,
+ve lead has 60mV drop
-ve lead has 6mV drop

Fixed

ps: even though I've fixed the 14V charging issue & it cranks strongly, once I stopped the engine it still struggles to hold enough charge going from 12.4 down to 12.10v overnight

guess something still drains it or the battery's dying

pollyp · Dec 14, 2024

2024-12-13 Fix Exhaust Drone with J-Pipe

My custom 2.25" exhaust system was often quite loud & boomy for years but ever since I fitted the new equal-length manifold the exhaust had a very noticeable, loud & annoying drone when cruising at 3.1k rpm

I read this page about calculating & making a 1/4 wavelength J-pipe resonator

https://strikeengine.com/helmholtz-resonator-calculator-exhaust-j-pipe-length/

Few years ago I did try making a J-pipe with no success but this time I'll have more data for better results.

https://micra.org.uk/threads/pollymobiles-rebuild.35251/post-767679

I downloaded the mobile app "Spectroid" which allows me to analyse the spectrum of exhaust sounds & identify the loudest resonating frequencies causing this drone while driving.
Combined with onboard video & datalogging

The results are fascinating

The system resonates loudly at 52hz, 104hz, 208hz (basically every 52hz increment) especially when engine reaches 1560rpm, 3120rpm & 6150rpm

Footage shows that at the same 3120rpm point, increasing TPS & engine load produces more exhaust gas pressure which makes it resonate louder at approx 208hz

At 6150rpm which is at twice the previous resonating rpm, it hits the same resonating freq of 52/104/208hz but since the engine is now producing it's maximum pressure/load, it produces the loudest drone

After some calculations, I figured the J-pipe needed to be approx 433mm long.
Modelled some rough pie-cuts I'll be making out of a spare 1.75" pipe I had in the garage to plumb into my decat pipe & sits next to the mid-pipe silencer.

pollyp · Dec 16, 2024

2024-12-15 Making an Adjustable Exhaust J-Pipe

Refined the design to fit within the existing de-cat pipe with a support bar & clear the large mid-pipe resonator

Cut afew pie-cuts to make the 1.75" 1.25D smooth bend

Welded the bend

& trimmed the end to fit the 2.25" exhaust pipe

Since I dunno the exact exhaust gas temperature within the J-pipe, which would vary the required pipe length to target 208hz ranging from 400mm to 443mm, welding a solid end cap only to find out it's the wrong length & need cutting/welding would be a PITA

So I decided to make a temporary adjustable end cap by machining a pair of round chamfered pistons

By tightening a long bolt, this squeezes an O-ring inbetween the chamfered pistons which wedges & locks the end cap inside the J-pipe

I can tune the J-pipe by simply sliding the plunger in/out to vary the chamber length,
tighten the bolt to squeeze the O-ring & lock the plunger in place,
test with the Spectroid app if the droning noise has gone,
readjust if needed,
once I found the optimum position I simply cut the pipe to the required length & weld a permenant end cap

Recorded a video explaining the J-pipe

pollyp · Dec 17, 2024

2024-12-16 Fitting & Tuning Adjustable J-Pipe

Marked & cut the hole on the de-cat pipe

J-pipe welded on

Just enough weld penetration so that the bends are still smooth inside

Installed ready to tune

Marked the plunger positions so it's easier to measure length

To tune the J-pipe, first I drove for few miles to warm up the exhaust system and cruising at 70mph with the wrong setting the droning is definately less than before.

After a long cruise, the front of the J-pipe attached to the main exhaust pipe gets a warm 30-50C while the rear end stays at an ambient 20C, so the chamber doesn't really get that hot.

Once warmed up, the 1st test is to change the resonator length from 380-450mm, free-rev in neutral upto 3800rpm and note the measurements for each setting.

Revving under no-load doesn't create as much gas-flow therefore droning but it's interesting to see that as the J-pipe gets longer, the major frequency peak of 124hz corresponding to the engines rpm / firing frequency which is (3800rpm * 2 pulse per rev)/60 = 126hz remains the same amplitude but the other frequencies above/below gets slightly quieter

Next test is tuning the J-pipe to target the 208hz drone when cruising at 3120rpm.

at 0:00 - 2:10 while accelerating & allowing the steering to flick the other way quickly, the ignition randomly cuts, jerking the car, I can hear the IGN relay clicking on/off & blinking the EML during each judder?

It doesn't happen at all during normal driving elsewhere, only happens during this testing session.
Wondering if this is a bad IGN switch or the same bad wiring/connection within the Nistune ECU I had years ago?

at 2:10 - 3:50 I adjust the J-pipe from 380-450mm,
go for a consistant 3rd gear WOT pull from 2-5k rpm so the engine creates max exhaust pressure & droning,
measure & compare the frequency graphs for each setting.

As the pipe gets longer you can see it begins to target/dampen the lower frequencies but going too long at 450mm it starts allowing the 208hz drone through.

The optimum length seems to be 390mm with the lowest/quietest overall dB.
And now cruising down the motorway it definately doesn't drone anymore

I also recorded what it sounds like between having the Powerflow silencer, resonater & J-pipe, giving the usual muffled note vs a straight-pipe (by removing the J-pipe end cap) and holy crap she sounds brutally different, naughty, raspy & chavvy lol

Gave me a cheeky surprised smile

pollyp · Dec 19, 2024

Marked where to cut the pipe

Made an end cap

Welded

The droning is not as severe as before but there's still a little hint of that 208hz resonance, maybe cos the end-cap wasn't cut perfectly square (affecting how the sound reflects back) or maybe it was slightly off the optimum length?

pollyp · Dec 21, 2024

2024-12-20 Stainless Fuel Filler Pipe

Been wanting to replace the factory mild-steel fuel filler pipe with a stainless version cos they all eventually rust from being exposed in the wheel arch, leading to rust in the fuel tank, clogging the filters & pump, & leaking fuel.

Began stripping apart a spare pipe to measure up

Gonna re-use this screw thread & cap

This device inside the pipe only allows unleaded fuel nozzle to be inserted,
helps reduce splashing back while filling,
the sprung flap helps stop fuel gushing out if the car was inverted,
& the breather port at the side allows the tank to freely vent out/equalise pressure while filling up.

May initially leave this out cos I don't have the correct 1.75" pipe to fit it yet

Cutting the breather pipe off for easier access & marking out all the complex bends to measure up

3D modelled the factory filler pipe

Planned all the pie-cuts required from a straight bit of stainless pipe

Marked all the required cuts

Carefully cut each section on the bandsaw

All cut, cleaned, labelled & ready to weld next

pollyp · Dec 22, 2024

Tacked the pipes together.
It roughly matches the old one but I'll need to verify fitment on the car before fully welding it up

For the funnel opening, the only 2" stainless pipe available that fits the screw fitting had a slot cut along it,
so I began welding it together

To taper the 2" funnel down to the 1.375" filler pipe, I marked & cut the pie-cuts

welded the funnel

& trimmed to fit the filler pipe

ready to test fit next

pollyp · Dec 23, 2024

Drained approx 1L out the tank from when the light comes on till the pump runs dry

Removed the old filler pipe since it was fitted in 2017, still intact & not rust

The epoxy primer & hard coated wheel well paint keeping rust away

Will restore the sills with the same stuff next.

The new pipe fitting nicely

Welded it all up fully

Next is to recreate the breather pipe in stainless

Old pipe vs new stainless pipe

Fits great

Next task is securing it with brackets & make a shield between the filler pipe & the chassis hole

pollyp · Dec 24, 2024

Welded brackets onto the pipe

Recreating the cowel with a stainless lid

Trimmed the edges

Trimming the cowel to match the angle of the opening

Old pipe vs new stainless pipe

fits perfectly

Old fuel filler vs new filler

Hopefully I won't ever have to worry about it rotting & getting rust in the tank

After xmas, I'll begin repairing afew rust holes around the car before her MOT in Jan

Micra Paul · Dec 25, 2024

pollyp said:
Welded brackets onto the pipe

View attachment 89611

Recreating the cowel with a stainless lid

View attachment 89612

Trimmed the edges

View attachment 89613

Trimming the cowel to match the angle of the opening

View attachment 89614

Old pipe vs new stainless pipe

View attachment 89617

fits perfectly

View attachment 89615

View attachment 89616

Old fuel filler vs new filler

View attachment 89610

Hopefully I won't ever have to worry about it rotting & getting rust in the tank

After xmas, I'll begin repairing afew rust holes around the car before her MOT in Jan

Impressed with such man hour’s time & dedicated skilful work restoring this 32 year old K11?

Jobs a goodun!

Happy Christmas.

pollyp · Dec 25, 2024

Micra Paul said:
Impressed with such man hour’s time & dedicated skilful work restoring this 32 year old K11?

Jobs a goodun!

Happy Christmas.

merry christmas m8

pollyp · Dec 26, 2024

For the upcoming MOT I needed to reinstall the secondary cat but first I had to cut the old flange off (was for the janspeed exhaust)

Cut the spare V-band off the old manifold, which I won't be using anymore

Welded the V-band onto both ends

pollyp · Dec 26, 2024

2024-12-26 Repair Rear Left Damper Turret

Time to assess this rusty left turret mount

Ah, wirebrushing the rust off reveal it's worse than I thought

Gonna have to rebuild this section

Chopped the rotten section out

Grinded clean the thick CO2 canister cup which I'll re-use

Reconstructing the turret mount

Added the thick top cup and a cover which fully surrounds the cup now to stop moisture seeping in

So that's the rear end & filler pipe fixed.
I'll check the rusty sills next

In other news, after a yr of depression/anxiety I start a new job tomorrow as a care home assistant which my m8 referred me to. A new start to the year

pollyp · Dec 27, 2024

Dismantling the front end was getting extensive as I removed the LED underglow, removed PAS cooler, front wings & reroute the loom

Drivers sill ain't too bad, simple patch up

Passenger side requires a more extensive patch

pollyp · Dec 29, 2024

Chopped the rust out

Some of my worst welding with paper thin rusty steel and a very cramped dark garage

Patched the drivers side too

After grinding the welds mostly flat, it's time to mixed the epoxy primer & polyurethane top coat.
They are certainly beyond their best-use-by date since 2019 but still useable

Both sills painted, wait 10hrs before the top coat.
I'm exhausted

Micra Paul · Dec 30, 2024

I feel, quote “exhausted” just reading & comprehending the endless skilful work restoring this 32 year old K11.

pollyp · Jan 1, 2025

Epoxy primer & grey topcoat applied

Chopping the rot off the drivers wing

Welded

Painted

Also reinforced this corner which holds the front bumper end

Painted black & reassembled.
Went to fill the empty tank, fuel nozzle was able to be inserted ALL the way into the filler pipe lol, but the splashing kept tripping the pump so I had to position it half-way & tilt upward so the nozzle cut-off sensing port was clear. Took 35L

Getting the PAS rack ready to swap over

The angle of this high pressure hose end would make the hose rub against the brake booster

Chopped the locating peg off

So the layout can be adjusted to clear the engine bay

The random ignition power cut I had recently was still happening whilst driving to/from the fuel station.
Basically during low rpm if I jerk the engine mounts back/forth by pumping the throttle on/off quickly or apply high load, the IGN relays would repeatedly click, engine light ON during each click, cutting fuel & jerking the car.

I remember the same thing might have happened back in 2019 when I found Nistune board had a dry solder spot.
Opened the ecu but couldn't see anything odd, the solder is soo tiny.

The spare ecu next to it was a facelift ecu. It would still operate the pump etc but cos I removed NATS wiring it will cut fuel & blink EML after 4s, so would require a fresh £200 Nistune type4 board to function, which tbh ain't worth it since I already have a standalone in storage to be installed one-day.

Just hope that this botched old Nistune board holds out long enough for the upcoming MOT, till I turbo the car & till I'm able to fit & tune the standalone

pollyp · Jan 3, 2025

Replaced both worn/rusty tie-rod ends with new dust boots

Reinstalled the power steering rack.

Instead of having a power steering cooler, I simply plumbed the return hose straight back to the reservoir to simplify and I doubt it gets that hot anyway

Replaced both worn out lower ball joint bearings.
At £35 each I'll need to find a cheaper more reliable option someday

Steering & suspension sorted

MOT expires tomorrow so one last test drive beforehand. Immediately the power steering is soo nice & effortless and LSD doesn't stutter as badly

As for the Ignition cutting out, I found a loose ground strap at back of the engine head near the PCV. After tightening, it hasn't misfired so far even after jerking the engine on/off throttle and launching it

Booked local MOT for tomorrow morning, hope all that hard work pays off

pollyp · Jan 4, 2025

2025-01-04 Failed MOT

Drive her up down the road to warm her up before going to the local test centre on a chilly morning.
The guy did a quick check over & hooked up the emissions test.

She struggled with the first fast-idle test for 30sec, reading 0.54% CO (limit 0.30%) but a good 61ppm HC.
So he ran the longer 3min fast-idle test, which usually gets the cat hot enough on most cars to clear. As he holds 3krpm I could see it go from 0.90 very slowly down to 0.62% as it heats up but no lower

HC & lambda passed.
natural idle was 0.42%, within the 0.50 limit.

Wondering what's going on & how to fix, I'm guessing either:
- new universal primary sports cat I fitted to the new manifold along with the secondary cat are cheap fakes with not enough catalyst in the honeycomb to function?

(maybe a reason they're a cheap £30 from ebay/china?)
- Nistune map (originally meant for janspeed 421 header) is likely tweaked too rich? Although the wideband stays at 14.7afr
- Injectors or filter are clogged (cos short/long fuel trim is adding abit of fuel in the closed loop although AFR are good when going WOT/open-loop

)
- MAF is dirty & under-reading?
- HC is low, so she's not burning too much oil.
- Too much condensation inside the big exhaust & steam coming out on this chilly day affecting the overall emissions readings

Decided to stop after the emissions test, skip the MOT test so I didn't have to pay for it yet and drove her home to fix again

So my plan is to swap back to standard manifold, standard ecu map, maybe clean the injectors & MAF. I can't drive her around to test drive or heat-up the damp exhaust cos MOT expired so that's inconvenient.

Removed the new manifold

Old gasket leaking slightly

Universal cat honeycomb looks ok but dunno if they were actually working?

Gotta mod this standard exhaust to fit the rest of my system

Chopped the old flange off

I'll have to adapt a 2.25" V-band onto the 1.5" down pipe

Tapered the end of the 2.25" pipe

Welded the V-band & support nut onto the down pipe

Fitted

Swapping the MAF over, the current sensor reads 1.10v at idle while the spare MAF reads 1.08v idling but the IACV solenoid also sits at different values

Swapping nistune over to the standard map & clearing self-learn, the AFR goes to a lean 15-16afr (too much air/lack of fuel) and then shortly see the fuel trim increase to richen it back to 14.7 target.

I'll retest the emissions on monday

Micra Paul · Jan 5, 2025

Always put my old banger K11 in for MOT test up to a month early to earn a month’s grace runabout to mess around DIY fixing any MOT issues with a no hassle still valid pre-existing ticket?

1275 · Jan 5, 2025

Micra Paul said:
Always put my old banger K11 in for MOT test up to a month early to earn a month’s grace runabout to mess around DIY fixing any MOT issues with a no hassle still valid pre-existing ticket?

As long as the fail isn't dangerous or major.

Driving a vehicle that’s failed
You can take your vehicle away if:

your current MOT is still valid

no ‘dangerous’ problems were listed in the MOT

Otherwise, you’ll need to get it repaired before you can drive.
If you can take your vehicle away, it must still meet the minimum standards of roadworthiness at all times.
You can be fined up to £2,500, be banned from driving and get 3 penalty points for driving a vehicle that has failed its MOT because of a ‘dangerous’ problem.
Previous:How the MOT test works

pollyp · Jan 5, 2025

2025-01-05 Ultrasonic Clean Fuel Injectors

So last night after swapping the exhaust & mapping over, I noticed during idle the fuel trim was adding upto 8-15% extra fuel just to keep it at 14.7afr, suspecting the injectors are slightly clogged at low-duty.

Guides online suggest few methods to clean injectors from adding additives, force feeding the fuel rail, ultrasonic cleaning each injector and making a special device to flush injectors whilst triggering them on/off.

Brought some additives to add in the full tank but tbh that won't take effect without going for a very long sporty cruise, idling or revving in the garage probably has minimal effect.

Cba or don't have the time to setup some special injector purging/triggering device.

So the next best thing is to remove the injectors and ultrasonic clean them.

The current injector pintles look ok, just some tiny debris around the outside

Removed injectors

I had this cheapo ultrasonic cleaner in the house meant for small jewellery/watches, dunno if its any good but worth a try.
After some research on what solution to pour in, I decided to pour a bottle of 99% isopropyl alchohol I had usually for cleaning electronics.

After 15mins it did an ok job of loosening most of the loose dirt etc

Reinstalled, replaced the old philip screws with stainless allen screws

Now with cleaned injectors and full tank of injector cleaner I fired up the engine, cleared the fuel trim, warmed up the engine till fan spins afew times and now I notice the short/long term fuel trims are very good at 0-5% and wideband at 14.7afr, meaning the injectors are now jetting the correct amount of fuel relative to the MAF reading

Curiously remembering jack mentioning that an exhaust sat for too long & running too cold may build up too much condensation/steam throughout the exhaustm which may overall affect the MOT emissions reading

So with the car warmed up & idling I measured the temps:
- Primary cat before/after = 220/180C
- Secondary cat before/after = 120/80C
- Back box silencer before/after = 30/20C

It seems at idle the back box casing at 30c ain't hot enough to evaporate the trapped condensation, I'm seeing water drip from the bottom casing drain holes, vapour condensing within the exhaust tip and warm steam coming out in the chilly air. It requires a good long hard cruise to fully cook the moisture away.

Micra Paul · Jan 6, 2025

1275 said:
As long as the fail isn't dangerous or major

That goes without stating the obvious, the MOT basic rules!

Who loves ya baby?

pollyp · Jan 6, 2025

2025-01-06 Passed MOT

Booked a new MOT for the afternoon.
Cleaned the dizzy cap,
Recalibrated the wideband sensor incase it was reading slightly off.

To warm up the whole exhaust, especially boiling away any condensation trapped in the colder backbox to reduce any steam & have better chance of passing emissions, I raise the idle to 1500rpm by opening the IACV in NissanDataScan.
This brings the primary cat upto 250c, second cat upto 120-150c.

Meanwhile to heat up the stainless back box separately I initially tried using a heat gun which brought it upto 60c, but that was probably using alot of power for tiny results

I had alot of dirty leftover isopropyl alchohol from ultrasonic cleaning the injectors.
Poured it into a tin can to light fire under the silencer, this cooked it upto 160-250c, it's free and also coated the silencer in matt black soot so I won't need to spray it black either

With the car warmed up I drive round the block to fully heat up, head over to the MOT, he hooked up the emissions machine.
Revving upto 3k on the initial 1st 30sec test the CO started off at 0.55 > 0.90% but seconds later as the cats heat up it suddenly dropped to 0.20% in the green and passed

Guess the prev emission failure was a combination of wrong map, dirty injectors and faulty fake cats

Few minutes later after he checked the rest of the car, she passed with no advisories! yipeee

Such a relief

Back at home a new MANN WK66 fuel filter also arrived

Opening the old filter

There's no major rust debris inside which is good. The previous filter years ago had rust from the old rusty filler pipe.
The filter paper is slightly darker so it caught some tiny dirt over the 2yrs, good thing I'm changing it now

So that's kassandra sorted for another year. Afew tasks to work through next before she can drive long distances

Micra Paul · Jan 6, 2025

pollyp said:
2025-01-06 Passed MOT

Booked a new MOT for the afternoon.
Cleaned the dizzy cap,
Recalibrated the wideband sensor incase it was reading slightly off.

To warm up the whole exhaust, especially boiling away any condensation trapped in the colder backbox to reduce any steam & have better chance of passing emissions, I raise the idle to 1500rpm by opening the IACV in NissanDataScan.
This brings the primary cat upto 250c, second cat upto 120-150c.

Meanwhile to heat up the stainless back box separately I initially tried using a heat gun which brought it upto 60c, but that was probably using alot of power for tiny results

View attachment 89704

I had alot of dirty leftover isopropyl alchohol from ultrasonic cleaning the injectors.
Poured it into a tin can to light fire under the silencer, this cooked it upto 160-250c, it's free and also coated the silencer in matt black soot so I won't need to spray it black either

View attachment 89705

With the car warmed up I drive round the block to fully heat up, head over to the MOT, he hooked up the emissions machine.
Revving upto 3k on the initial 1st 30sec test the CO started off at 0.55 > 0.90% but seconds later as the cats heat up it suddenly dropped to 0.20% in the green and passed

Guess the prev emission failure was a combination of wrong map, dirty injectors and faulty fake cats

View attachment 89706

Few minutes later after he checked the rest of the car, she passed with no advisories! yipeee
Such a relief

View attachment 89707

Back at home a new MANN WK66 fuel filter also arrived

View attachment 89708

View attachment 89709

Opening the old filter

View attachment 89710

There's no major rust debris inside which is good. The previous filter years ago had rust from the old rusty filler pipe.
The filter paper is slightly darker so it caught some tiny dirt over the 2yrs, good thing I'm changing it now

View attachment 89711

So that's kassandra sorted for another year. Afew tasks to work through next before she can drive long distances

Jobs a goodun!

pollyp · Jan 7, 2025

Tday straightened the alignment & swapped back to the new manifold

The mapping needs more refining cos it keeps leaning out it certain spots or requires lots of fuel trim cos of the better flowing manifold

villanueva_00 · Jan 10, 2025

Hi Paul i had lots of trouble passing emission with my preface 1L K11. Stock map, cleaned injectors, good MAF values and okay response for the 02 sensor. I even changed the middle cat an still wouldnt pass CO test.
So i used a facelift front cat (which is about 40mm longer). This one supposedly is under the rules of Euro3 instead of Euro2 so with that one i got a 0.0% on CO. (Euro 3 had a bit more restriction on HC and CO so even used should be better than the Euro 2 ones)
Just saying as a suggestion as i think i bought that cat for like 100 Euro on Ebay.
Hope it helps for next MOT i guess!

pollyp · Jan 10, 2025

villanueva_00 said:
Hi Paul i had lots of trouble passing emission with my preface 1L K11. Stock map, cleaned injectors, good MAF values and okay response for the 02 sensor. I even changed the middle cat an still wouldnt pass CO test.
So i used a facelift front cat (which is about 40mm longer). This one supposedly is under the rules of Euro3 instead of Euro2 so with that one i got a 0.0% on CO. (Euro 3 had a bit more restriction on HC and CO so even used should be better than the Euro 2 ones)
Just saying as a suggestion as i think i bought that cat for like 100 Euro on Ebay.
Hope it helps for next MOT i guess!

good shout, I remember the facelifts have a much bigger primary cat, more material, all located close to the hot manifold to eliminate the need for secondary cat under the gearstick (which is usually cooler & useless).
I'll consider grabbing a facelift cat at some point as a last resort for next MOT

pollyp · Jan 14, 2025

Angled the PAS hose slightly to the side to clear the M/C and engine head to stop it rubbing/buzzing

The throttle cam on the spare TB sat slightly mis-aligned

So I cut & welded it 1cm slimmer

Now it swings smoothly

Took a quick teesside pic of her at this moment before work

On personal note I tried care work since Dec, learnt alot but it was too much stress & didn't workout for me but on the positive side it helped motivate me to seek a better career towards perhaps mech design engineering? (i need careers advice tbh) and found a lady I have lots in common with too which gives a nice boost