Cutting out when Warm

skymera

Brutal Honesty
Just had a really weird thing happen with my Micra. It just cuts out when idling :eek:

Bit of background.
This car has always had a noisy chain, however recently it seems to have a got a lot worse and I believe the chained to have stretched and causing timing issues.

Drove 20miles home on the M4. Traffic was slow so I was in 2nd gear crawling at about 1,000RPM. Used a little gas to speed up and there was a delay then a big jolt. Happened a few times.

pulled up at home, other than sounding like a bag of nails it repeatedly cut out.

I'm willing to accept this car has now met it's fate and maybe ready for the scrapper but has anyone got any ideas!?

 
Okay, been fiddling with the TB.

Idles a little higher with the idle valve unplugged, but still cut out.
Same goes for the maf, cuts out.

BUT it only cut out once it reached mid-way on the temp gauge.
The engine had time to cool down for a bit and it started and idled no problem. Once the temp needle reached half way it started running lumpy, seemed to misfire and then cut out.

Ideas? Coolant sensor or something?
 
definitely worth a try scott :)

Well the cap was pretty furry so cleaned it up. Rotor looked fine.

Seemed to narrow it down a bit. Unplugged the MAF and the car idled okay, little rough. plugged it back in and the car cut out immediately.

So looks like a new TB is in order :)
 
well the thermostat leans the mixture out when hot right? maybe it's leaning it out too much when it gets hot, could be worth swapping it for a new one?
 
you can buy a cg13 for the cost of the timing chain. I say do it now and ditch the massey ferguson power plant.
 
It was on my list for later this year, may have to bring it forward and leave the body for later.

Car is driving fine this morning ..
 
Okay, so I made it to work.

MAF still plugged in.

Car ran and idled fine when cold, no problems.

The jerkiness pulling away at low revs began after a few miles.
I noticed when I dipped the clutch at traffic lights, the revs stick to 1,100rpm-ish for about 5 seconds before dropping back to 750~.
And after about 10secs at 750pm idle, it cut out. But started no problem again after?

I'm clueless
 
Water temp sensor.
I had this issue with a seat ibiza. We changed the tb, maf, air temp, cleaned all plugs leads and dizzy.

It would run ok ish then would 'overrun' approx 1200rpm before dropping to idle. Nearly cut out but didn't. The dizzy was also on full retard too. Would always start ok aswel.
Once the water temp sensor was changed. The dizzy was put back to standard timing and off it went
 
It's driveable, little difficult at times so I wont bother fiddling with the stat.

I'll need to head over to MPD or Euros to get another sensor :) Unless you're off Chris and feel like being a babe?;)
 
Well the part just arrived, but it's the single pin sensor which I think is the dash gauge.

I need the 2 pin coolant sensor :( Balls
 
Well, I made it home. Just.

Revs are sticking to 1,200rpm when dipping the clutch, then dropping to 750rpm soon after then cutting out.
Tapping the accelerator pedal makes the revs jump to around 2,000 where it sits for a few seconds, then drops to idle and tries to cut out.

Pulling away in 1st is near impossible and requires high revs (2,000) or it just bogs down and jerks.

Left it idling outside my house, never actually cut out but it almost stalled about 20times in a minute. Spluttering a lot.

Idle air valve? Coolant sensor?
I'm ruling the MAF sensor out.
 
Well, I made it home. Just.

Revs are sticking to 1,200rpm when dipping the clutch, then dropping to 750rpm soon after then cutting out.
Tapping the accelerator pedal makes the revs jump to around 2,000 where it sits for a few seconds, then drops to idle and tries to cut out.

Pulling away in 1st is near impossible and requires high revs (2,000) or it just bogs down and jerks.

Left it idling outside my house, never actually cut out but it almost stalled about 20times in a minute. Spluttering a lot.

Idle air valve? Coolant sensor?
I'm ruling the MAF sensor out.
is it worse with the (2 wire) coolant temp sensor disconnected scott ?
 
Can't even get my hands in to unplug the thing.

Looks like the dizzy may need to be remove or something?
there,s a knack with those connectors scott :D when you squeeze the top it goes click, then lever it off with a flat screwdriver eh
 
there,s a knack with those connectors scott :D when you squeeze the top it goes click, then lever it off with a flat screwdriver eh

Wrestled with it for 20mins, and it finally came off!
I suffered a few scrapes on the numerous sharp things in the engine bay.

So 2pin sensor unplugged. Engine light was on and fan was on constant, normal I assume.
Drove 3-4 miles, temp needle was half way.
Pulling in 1st felt fine, no juddering. pulling in 2nd seemed to bog down a tiny bit, might be me being picky.
Idled fine at 750rpm for a good minute or so with no really splutters.

So is my sensor to blame?
 
it should overfuel markedly with that sensor disconnected mate (when hot) praps try linking the 2 wires ?

Oh, now I am baffled :confused: Thought I cracked it.

You mean just put a wire in each of the plugs to bridge it? What should I expect?
 
aye, a bridge wire scott, when i disconnected mine on the dyno it forced it into coldstart enrichment, and out of closed loop (and gave 13:1 a/f/r,s throughout)
bridging if should have the opposite effect (though the fsm manual says that spurious signals will limpmode it iirc)
 
aye, a bridge wire scott, when i disconnected mine on the dyno it forced it into coldstart enrichment, and out of closed loop (and gave 13:1 a/f/r,s throughout)
bridging if should have the opposite effect (though the fsm manual says that spurious signals will limpmode it iirc)

Not time to test that now. i'll go aherad and order another coolant sensor, it will only be a tenner with my 25% discount and it will be delivered same day.
Worth a shot being cheap :)
 
this is where a narrowband a/f/r gauge is mega useful for diagnosis, using it to check the engine is coldsart enriching and closed looping properly and checking if it goes off the scale lean or rich when the judder occurs etc
 
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