PollyMobiles Rebuild

[pollyp]

Didn't have much energy today but I managed to crimp the new relay wires together

Reassembled the loom & dash

Couldn't be bothered to correct the wideband wiring (connect 12v supply to the original O2 pink wire, add toggle switch to power-up wideband separately after cranking), check the ECU loom connectors are clean, and many other minor tasks cos it ain't essential yet and it still works ok.

Pump sounds abit stronger during cold priming with the higher voltage. She still drives like normal tonight, the odd rattle in the dash at specific rpm still there

 

[pollyp]

2025-02-15 Replace Walbro GSS250 255lph Fuel Pump

With approx 75% fuel level I removed the fuel pump assembly out of the tank.
Not a fun procedure, even with gloves

Opened the container & oh my god!

This clean face-lift fuel tank was swapped over 1 yr ago but now after filling it with mostly tesco / occasionally morrison fuel, there's soo much crap dirt in the tank/strainer

Poor pump strainer is covered in filth

Look at this tank!
I guarantee this tank was clean when it was swapped.
Non of this rust crap came from my car (old/new filler pipe wasn't rusty, pump itself ain't rusty).
It must certainly come from the old, badly maintained, cheapo supermarket fuel pumps

Old vs new Walbro GSS250 pumps

I flushed out as much of the debris off the strainer with can of carb cleaner

Fitted onto new pump

Pump, strainer & swirl pot all clean for now

Here's a comparison of how the pump sounds before/after.

First two clips were with fuel hose unplugged and fed freely into a fuel can with 0psi, while the last clip was with the hose connected onto fuel rail supplying 3 bar of pressure.

Old pump had a higher/faster/louder motor whine whereas the new pump (with fresh tighter tolerances?) has a lower pitch, especially once it's plumbed into the 3 bar fuel rail.

 

[Micra Paul]

Didn't have much energy today but I managed to crimp the new relay wires together

View attachment 89801

Reassembled the loom & dash

View attachment 89802

Couldn't be bothered to correct the wideband wiring (connect 12v supply to the original O2 pink wire, add toggle switch to power-up wideband separately after cranking), check the ECU loom connectors are clean, and many other minor tasks cos it ain't essential yet and it still works ok.

Pump sounds abit stronger during cold priming with the higher voltage. She still drives like normal tonight, the odd rattle in the dash at specific rpm still there

Loads of good work however may I suggest it would be advisable to replace all DIY temporary crimp joints with professional married electrical inline & tee joints soldered & sleeved?

Manifold fuel line/regulator pressures?

Married Electrical Inline & Tee Joints Soldered at DuckDuckGo

Keep up the good work!

 

[pollyp]

Loads of good work however may I suggest it would be advisable to replace all DIY temporary crimp joints with professional married electrical inline & tee joints soldered & sleeved?

Manifold fuel line/regulator pressures?

Married Electrical Inline & Tee Joints Soldered at DuckDuckGo

Keep up the good work!

Gradually working through my to-do list to replace all my nasty old weak solder with crimps
Next on my wiring list is to sort the wideband wiring.

 

[pollyp]

2025-02-17 Walbro GSS250 Fuel Pump Detailed Look

For a closer look at how the Walbro 255LPH internal gear type pump works and it's condition after 13yrs, I stripped it all apart

& 3D modelled it too

The port in the front plastic cover simply feeds fuel into the pump via this narrow slot.
The round hole at the bottom isn't used for output (maybe on a different model?) but instead it's just blocked off & keeps the front cover aligned

The pump unit separated from the motor casing, driven by these 4 prongs

This thin rigid backplate & brown slippery layer simply keeps the back of the gear pump sealed with minimal wear

The front brown gasket, which does most of the work sealing & controlling flow, seems quite worn.
Potentially the scoring marks maybe due to trapped debris from dirty supermarket fuel getting past the pump strainer

The gear pump face is also little worn. This will reduce sealing efficiency, less pumping performance, which may explain the higher motor pitch due to loose tolerance, less friction, less hydraulic pressure

In the model you'll see as the motor spins the pump clockwise, fluid enters the top slot as the gear teeth opens up.
At the bottom part of the cog, the closing teeth squeezes the fluid out (this additional loose brown 'tab' on the gasket might be used to smooth out the flow?)

Fluid then enters the casing via a narrow slot at the bottom. Seems like a kinda restrictive/rough path?

From that small slot, fuel flows through the motor casing, cooling the motor

The copper longitudinal commutator track, similar to the face-lift fuel pump, looks a little worn by 1mm.

Stator has a clear wrapping maybe for insulation & smoother fluid flow?

After cooling the motor, fuel goes to the rear section through these two holes & gaps in the graphite brush holder

In the rear section, most of the fuel flows through the regular output, which has a 1-way check valve to maintain fuel pressure after shutdown.
For non-return fuel systems, there's also an over-pressure relief valve which bleeds excess pressure back into the tank

The graphite brushes has plenty of life left

I believe these conductive end-caps are press-fitted into the rear section at the last-stage of manufacture so it's easy & fast to assemble the graphite brush springs and test the motor circuit simultaneously

Overall an interesting design to check out

Here's a look at the pre-face & face-lift pump for comparison
https://micra.org.uk/threads/pollymobiles-rebuild.35251/page-203#post-884005

 

[pollyp]

Recently noticed hearing a slight rubbing noise once-per-wheel turn only at low speed, shortly after applying brakes and after driving for few mins.
I suspect it might be the caliper rubbing on the edge of the discs (considering they were rebuilt recently)

Looking under the passenger caliper, not much signs of rubbing, just some brake pad dust

But the drivers caliper definately has some rubbing from the disc edge

I tried to shift the whole brake carrier further outward slightly but it still rubs after warming up the brakes from few mins driving

May have to remove the carrier cage and mill the hub upright bolt hole slightly oval to install the whole thing further outwards by 1mm till the top of pads sit flush with the disc edge and caliper has a larger gap from the disc

 

[pollyp]

The caliper carrier has upto 2mm gap from the disc edge

Whereas the caliper sits abit closer upto 1mm gap from the disc

notice the top of the pads have always sat 2mm too low from the edge of the disc

I drilled the bolt hole slightly further outwards to shift the carrier approx 0.5mm from the disc

Can see the top of the pads now sit past the old line on the disc

Went to heat the brakes up in country roads and Nope it still rubs
It sounds more like a rubber seal noise than a metal to metal sound,
Gets louder when cornering right,
& mostly under slight brake pressure but quieter under hard braking

The last time I experienced a similar thing was a loose wheel bearing due to the LSD.

I lifted the front on axle stands, run it on 3rd gear, apply slight braking and listening to the brakes for any rubbing, nope they're both quiet so they're definately not rubbing.

Both wheels don't show much side-side or vertical play but let's check the passenger shaft nut (which historically tends to loosen with the vibration off the LSD),
& sure enough the driveshaft nut was only loose by 5-10deg

Tightened the nut hard as I can and went for another drive and that's finally fixed the rubbing noise

 

[Micra Paul]

The caliper carrier has upto 2mm gap from the disc edge

View attachment 89842

Whereas the caliper sits abit closer upto 1mm gap from the disc

View attachment 89843

notice the top of the pads have always sat 2mm too low from the edge of the disc

View attachment 89845

View attachment 89846

I drilled the bolt hole slightly further outwards to shift the carrier approx 0.5mm from the disc

View attachment 89844

Can see the top of the pads now sit past the old line on the disc

View attachment 89847

Went to heat the brakes up in country roads and Nope it still rubs
It sounds more like a rubber seal noise than a metal to metal sound,
Gets louder when cornering right,
& mostly under slight brake pressure but quieter under hard braking

The last time I experienced a similar thing was a loose wheel bearing due to the LSD.

I lifted the front on axle stands, run it on 3rd gear, apply slight braking and listening to the brakes for any rubbing, nope they're both quiet so they're definately not rubbing.

Both wheels don't show much side-side or vertical play but let's check the passenger shaft nut (which historically tends to loosen with the vibration off the LSD),
& sure enough the driveshaft nut was only loose by 5-10deg

View attachment 89848

Tightened the nut hard as I can and went for another drive and that's finally fixed the rubbing noise

Quote; “carrier cage and mill the hub upright bolt hole slightly oval”

Well investigated however needs comparison of discs outside diameter dimensions equality & compared to OEM discs?

Milling/drilling out mounting holes on critical brake components would not be advisable & may introduce parts movement together with stress fractures in future?

Good luck

 

[pollyp]

Quote; “carrier cage and mill the hub upright bolt hole slightly oval”

Well investigated however needs comparison of discs outside diameter dimensions equality & compared to OEM discs?

Milling/drilling out mounting holes on critical brake components would not be advisable & may introduce parts movement together with stress fractures in future?

Good luck

Cheers
All of the GTIR discs I've ever brought have the same dimensions but the main problem is that the carrier cage and/or K11 hub bolt holes on mine makes the whole assembly sit 1-2mm too close to the disc until it rubs at high temp
But I remember other owners with same brakes didn't have this issue?

Yrs ago I had new discs machined smaller before fitting, but was uneconomical.
Then I later grinded the bottom of calipers 1mm to clear the disc, but couldn't grind too much out.
This last option here was to just slot 0.5mm of the hole to nudge the assembly out just enough to clear the disc, but given the remaining 10-15mm of thick steel around the hole I doubt it'll affect overall strength enough to worry about for daily driving unless i start fitting extremely oversized racing brakes and increase the stress loads on those bolt holes from more trackdays

 

[Micra Paul]

T

Cheers
All of the GTIR discs I've ever brought have the same dimensions but the main problem is that the carrier cage and/or K11 hub bolt holes on mine makes the whole assembly sit 1-2mm too close to the disc until it rubs at high temp
But I remember other owners with same brakes didn't have this issue?

Yrs ago I had new discs machined smaller before fitting, but was uneconomical.
Then I later grinded the bottom of calipers 1mm to clear the disc, but couldn't grind too much out.
This last option here was to just slot 0.5mm of the hole to nudge the assembly out just enough to clear the disc, but given the remaining 10-15mm of thick steel around the hole I doubt it'll affect overall strength enough to worry about for daily driving unless i start fitting extremely oversized racing brakes and increase the stress loads on those bolt holes from more trackdays Many

Many thanks for your interesting experience based response.

May I suggest shape overrides minimal material removed in order to equally distribute stress lines in circular lacuna compared to oval lacuna stress concentration of the resulting critical brake mounting stress ellipsoid.

Stresses At Elliptical Holes

Good luck

 

[pollyp]

It's been 1yr since I last checked the compression and 2yrs since checking valve clearances

Insides look good from regular 6mth servicing with 10w40 castrol gtx

Compression on all 4cyls are really good & equal

Ever since I rebuilt this engine with perfect piston ring gaps in 2019 and then tweaked the valve shims in 2022, all of the intake & exhaust now have perfect equal clearances

Nice

 

[pollyp]

2025-03-08 Check Peugeot 307 Fuel Pump

After seeing the terrible rusty debris in kassandras tank (suspecting it's either from the old rusty steel filler pipe or dirty tesco fuel?) I figure it's best to check out the 20yr old peugeots fuel tank

The peugeot uses a return-less fuel system & plastic filler pipe (so minimal chance of rust forming) but oddly it has no in-line fuel filter? purely relying on the rough little fuel pump pickup strainer

Unscrewing the huge 20yr old plastic collar without breaking it was a little tricky but some gentle leverage got it loose

Here's the whole fuel setup, the spring loaded top cover keeps the lower section pressed down close to the bottom of the tank

Very interesting that it features 2 separate swirl/reservoir pots, good for reducing starvation

Fuel first gets sucked into the 1st chamber via this orange 1-way valve close to the bottom of the tank

This lower chamber keeps the pump pickup submerged with afew ml of fuel at all times, even while the rest of the tank is sloshing around

The tiny pump strainer sits at the bottom of this primary chamber and is the only filter throughout the whole system

You'll see the pump in the center feeds fuel into a secondary pressurised swirl tank reservoir surrounding it, maintaining a consistant fuel supply.

1 output at the top feeds fuel to the injectors while the bottom output with the blue o-ring leads to the fuel pressure regulator

1 of the black hose from the center pump feeds into the secondary reservoir while the other hose sends fuel from the reservoir to the fuel rail

Looking inside the tank, reservoir & pump strainer it's surprisingly clean & rust-free, even after 20yrs filling up with cheap morrison fuel, which is a relief

 

[pollyp]

2025-03-18 Rebuild Garage Roof

My garage roof consists of a steel mesh cage covered with a mess of clear corrugated sheets, which tends to break from UV damage, high winds or being walked over, leading to annoying leaks over the car for the past few decades and I figure it's time to improve it

I modelled the roof & designed an arrangement of 1220x610x4mm polycarbonate twinwall sheets (durable enough to stand over, UV resistant, & most cost effective panel size)

Stripped all the old brittle sheets off the roof shell

Good time to give the rusty frame a lick of paint

Laid a waterproof sheet over the far wall to form a sort of lower rain gutter and bolted the 1st set of panels onto the sloping roof side

finished bolting the rest of the top panels & sealed all the joins with Gorilla crystal clear tape & regular flash tape

After 4 labour intensive & exhausting days luckily with good weather, I just managed to finish the roofing right before the rain was forcasted that evening.
The next morning with heavy downpour it's a relief to see that my idea worked and I finally have a waterproof dry garage to park kassandra in

 

[pollyp]

2025-04-19 FLIR One Gen3 Thermal Camera

Brought myself a FLIR usb-c thermal camera for many reasons including:
- check home insulation & heating system
- finding home appliances/electronics that wastes too much power/heat
- checking the cars cooling system, exhaust, brakes etc

After buying it I was disappointed to find that the FLIR app wasn't compatible with my Huawei phone
Thankfully I had a spare samsung tablet with a usb-C port which was FLIR compatible

Initlally thought I brought a faulty used FLIR off ebay cos the camera wasn't connecting with the app but soon got it working after several restarts, reboot, replugging, recharging etc I think it might be a software bug or FLIR battery issue

It's a really annoying bug but once successfully connected, it'll keep running till the battery runs out.

First thing I did was check/fix the home heating, insulation holes and disable any electrical wasters like TV, Stereo, network adapters, routers, power adapters, fish tank pump, game consoles etc

Then I tested it out on Kassandra during a cold start, which is fascinating & cool seeing how stuff warms up
The camera had trouble reconnecting again after I stopped recording



Figured the camera will connect to the app more likely by restarting the tablet, restart the app & reinsert the camera.
The next day I did a more detailed FLIR look at the car.



@00:05 Exhaust manifold heats up
@01:02 Warming up catalytic convertor
@02:05 Check brake temp after a short drive & coming to a stop
@03:05 Check engine bay temperature
@05:30 Exhaust silencer temperature
@05:50 Test cabin heater
@06:15 Hot engine bay after parking car in garage
@06:45 Engaging radiator fan
@08:25 Testing universal ebay catalytic convertor

So it turns out that the cheap 2.25"universal stainless sports cat I brought off ebay used on this new manifold might actually be a fake

After warming up the engine and holding high rpm, the core of the cat doesn't get hot at all and there's no temperature difference between both ends, meaning there's no reaction or any catalyst material within that fake honeycomb core, which might explain the really high emission readings during her MOT in january, even after revving her nuts off for 3min, and yet she passed easily after reinstalling the standard cat.

Also the rear left brake might be sticking slightly, making the disc appear a little warmer.

 

[pollyp]

2025-04-19 Replacing Catalytic Convertor Core

After discovering my current universal cat is fake & doesn't work, I wonder if I could replace it with some used oem cats I had in the garage cut to length

This cat from an Octavia had a spiral steel mesh core, which made it really difficult & slow to cut through

Unfortunately the rough bandsaw teeth would end up bending all the fine steel mesh, clogging the whole thing

The other longer bigger cat was from a peugeot 307, which has a regular ceramic honeycomb core.
I cut both ends off

Due to the softer ceramic honeycomb it was easier for the bandsaw blade to cut through and the hard/brittle ceramic material would cut/crumble cleanly

The result is a clean, flat cut with no clogged pores, so it's possible

The universal cat is 102mm diameter whereas the peugeots cat is 105mm diameter, near enough.
Plan is to cut this core off the current exhaust

Cut the peugeots core to length (want to use as much honeycomb length/volume as possible to give it more chance to help improve emissions) and weld it on like this

 

[pollyp]

2025-04-20 Compare Fake Cat vs Genuine Cat Using FLIR

Here's a comparison of the fake catalyst on my Micra vs a working cat on a Peugeot.

During Cold Start: The manifold gets hot immediately, catalyst core stays stone cold, and downpipe begins to warm.

After Driving 10min: manifold is very hot, catalyst core & downpipe are at their warmest.

After Idling in Garage: manifold stays hot but catalyst & downpipe has cooled down.

Holding 3k rpm for 3min: manifold gets hotter but catalyst core & downpipe stays same temperature.

The Peugeot 307 with a working cat is very different.

During Cold Start: manifold & downpipe gets hot immediately, upper half of the catalyst is cold, lower half of catalyst warms up quickly as the gas flow reacts & gets hotter.

Idling 1min: upper half of the catalyst begins to heat up from reacting with gases.

After Driving 10min: the whole exhaust system is very very hot beyond the 150c limit of the thermal camera

Comparing the brakes & exhaust silencer temp of the Micra with the Peugeot after 10min of cruising and both appear with similar appearances.

 

[pollyp]

2025-04-21 Replacing Fake Cat with Genuine Cat

Began removing the fake universal cat

Looking at how close the cat is to the block, I decided not to fit a longer catalyst core

Can see some signs it only got hot at the top near the manifold but the fake honeycomb core and the lower outlet never got hot enough

Chopped off the funnel ends.
The fake stainless cat is 101mm diameter while the Peugeots cat is 105mm diameter.

Top of the honeycomb only a little soot but doesn't look like it got hot

Bottom of the honeycomb looks the same light pink as when new, indicating no reaction or high heat.
Normally the hotter exit end of a used cat would appear pale & white from the intense heat of reaction.

I chopped the spare Peugeots catalyst core to match the same length

Clean cut

Dremelled loose some of the white insulation fibres between the honeycomb and steel casing to allow the smaller funnel ends to slot within the groove

Tacked & welded together

As a reminder, here's the thermal image of the fake cat which never got hot at all

And now with a working genuine core taken from a spare Peugeot 307, you can clearly see the cat & downpipe getting hotter from reacting with the exhaust gases and high rpm

Here's footage comparing the two



Hopefully for her MOT next yr this will help with emissions