16 replies to this topic

[zimmer]

The zimmermobile's once again got engine problems..... No EML codes It was running fine for the north east meet, then I went out for a moderate drive with the missus and it seems to have developed an intermittent misfire. First time was slowing down for a roundabout on a dual carriageway, 70mph to 15ish through the gears, then when I try to accelerate gently in 2nd, it starts to sound like a subaru. Foot down a bit more and it clears spontaneously after a few seconds. I cannot reproduce it every time but it appears to only happen when engine is warm, only when slowing down from speed then gently accelerating. If I don't accelerate when it occurs, the misfire continues until I accelerate or let it idle. I have a piper exhaust which pops and burbles a lot, and it seems to happen mostly if I accelerate when it is burbling (ie on the overun at low revs) - not sure if this is significant. Now I had similar problems earlier in the year. First time was a duff injector. Second was where I had swivelled the EGR and not tightened the blanking plate properly leading to a leak which gave similar symptoms. Therefore it has had a new coil pack, new plugs, replacement ecu, four reconditioned injectors (off ebay ) all within the last 6 months. I also replaced the coolant temperature sensor - with the new one I was only reaching temps of 81-82 degrees. Having swapped back to my old one, the temp's now back to normal but it hasn't cured the problem. The EGR blanking plate is secure with gasket in place. The EGR valve is swivelled round - removing it brings up the EML but has no effect on the running problem. I have a courtenay panel filter and drilled airbox, I can't see an obvious air leak. The manifold is standard. Car has done 40k miles and was serviced last month (though they didn't replace the oil filter as had no seals, and told me fuel filter didn't need doing yet) Oil and coolant levels are fine. No rattling to indicate timing chain problems (and surely this would cause constant misfire) I'm running out of ideas - it feels to me like a fuelling issue, but I haven't really got a clue. Has anyone had anything similar? Any ideas where to start? Help!

[chrisgold]

The zimmermobile's once again got engine problems.....
No EML codes

It was running fine for the north east meet, then I went out for a moderate drive with the missus and it seems to have developed an intermittent misfire.
First time was slowing down for a roundabout on a dual carriageway, 70mph to 15ish through the gears, then when I try to accelerate gently in 2nd, it starts to sound like a subaru. Foot down a bit more and it clears spontaneously after a few seconds.
I cannot reproduce it every time but it appears to only happen when engine is warm, only when slowing down from speed then gently accelerating.
If I don't accelerate when it occurs, the misfire continues until I accelerate or let it idle.
I have a piper exhaust which pops and burbles a lot, and it seems to happen mostly if I accelerate when it is burbling (ie on the overun at low revs) - not sure if this is significant.

Now I had similar problems earlier in the year. First time was a duff injector. Second was where I had swivelled the EGR and not tightened the blanking plate properly leading to a leak which gave similar symptoms.

Therefore it has had a new coil pack, new plugs, replacement ecu, four reconditioned injectors (off ebay ) all within the last 6 months.
I also replaced the coolant temperature sensor - with the new one I was only reaching temps of 81-82 degrees. Having swapped back to my old one, the temp's now back to normal but it hasn't cured the problem.
The EGR blanking plate is secure with gasket in place. The EGR valve is swivelled round - removing it brings up the EML but has no effect on the running problem.
I have a courtenay panel filter and drilled airbox, I can't see an obvious air leak.
The manifold is standard.
Car has done 40k miles and was serviced last month (though they didn't replace the oil filter as had no seals, and told me fuel filter didn't need doing yet) Oil and coolant levels are fine.
No rattling to indicate timing chain problems (and surely this would cause constant misfire)

I'm running out of ideas - it feels to me like a fuelling issue, but I haven't really got a clue.
Has anyone had anything similar?
Any ideas where to start?

Help!

For me this was a pre cat Lambar sensor. However should show when you plug it in.

Plugged it in since its started doing it?

Is it running rich?

[zimmer]

I've heard the pre-cat lambda can cause trouble before giving a code. I did change mine last year but it was an ebay job, so could be that it's on its way out. Plugged it into my OBD reader, it's not showing anything Exhaust is very blackened, maybe it is running rich. Thanks for the advice, might be worth getting a new lambda sensor anyway

[DEKKER]

I had the exact same symptons a couple of months ago . Someone suggested it was accelerater peddal related so I disconected the block above the peddal and the one in the engine bay , cleaned up the terminals (which all looked ok to me),reconnected and have not had the problem since . Maybe I was just lucky but worth a try .I had a blackened exhaust to , that has also cleared up.

[wil_scotland]

I doubt this is the electronic sensor on the throtle peddle. If I had to guess I would go with doggy injectors or water in the head down the spark plug chambers causing a miss fire. Thats my two pence but would really need to see it. I would doubt it will be a fuel issue as no much usually goes wrong on this side in vx220s. good luck Wil

[chrisgold]

I've heard the pre-cat lambda can cause trouble before giving a code. I did change mine last year but it was an ebay job, so could be that it's on its way out.
Plugged it into my OBD reader, it's not showing anything
Exhaust is very blackened, maybe it is running rich.

Thanks for the advice, might be worth getting a new lambda sensor anyway

Im no expert, but if the exhaust is very blackened, its defo running rich, if its running rich it will soot up all your plugs which is what causes your misfire. So regardless of of weather its your Oxygen sensor, you have found the cause of the misfire, you just need to now find the cause of why its running rich.

No problems, glad I could help.

[evo2avxr]

Thought I would add to this thread - as a recent find. My VX220 turbo suffered a misfire - thought it was the coil pack breaking down, or plugs, or fuel - bad missing on light load, but oddly cleared when on the power. Black exhaust. Tick-over very rough - then occassional cutting out completely. Finally I think I have tracked it down to the preCAT lambda. NO fault code or engine light at all. Unplufg the preCAT lambda and it runs ultra smooth. Not driving it until new one fitted. Ordered a new part from AutoVaux - let's see.

[zimmer]

Thread resurrection and a half! My problem sort of went away by itself, have since fitted a piper manifold and a standard turbo back box, now ticked over 62k and without any further problems (touch wood). Hope the new lambda sorts yours

[evo2avxr]

Thought I had better report back on this one. New preCat lambda sensor fitted, and problem seems to have been solved.

[Detta]

I'm having similar symptoms, but not nearly so pronounced. It has just developed that 'Subaru sound' on gentle acceleration between around 2.5-3k and is running a little rich. As above applying more power clears it up. Being a total noob myself how easy is it to get to the pre-cat lambada sensor, is it tray off, under the car somewhere pre-cat as one would expect? And is it safe to run without for the sake of testing evo2avxr?

Edited by Detta, 14 November 2012 - 10:18 AM.

[fezzasus]

FYI, I know it's after the fact but the swiveled EGR valve shouldn't throw up an EML light - the whole point of keeping it there and connected rather than removing it completely is to trick the ECU into thinking it's still functioning and not throwing up an EML light.

[fezzasus]

I'm having similar symptoms, but not nearly so pronounced. It has just developed that 'Subaru sound' on gentle acceleration between around 2.5-3k and is running a little rich. As above applying more power clears it up.

Being a total noob myself how easy is it to get to the pre-cat lambada sensor, is it tray off, under the car somewhere pre-cat as one would expect?

And is it safe to run without for the sake of testing evo2avxr?

Really easy to get to. Rear tray off, it's the one closer to the front of the car. 22 mm spanner and trace the connector to the top of the gearbox next to the two large coolant hoses. I wouldn't recommend running without one as the car will have no idea what fuel trimming to use, not to mention leading to a blowing exhaust and all sorts of engine running issues.

Get a new one - get an NGK part code OZA531-GM6 (for NA 2001 or later) or OZA531-GM1 (pre 2001), you can get one off ebay for around £50, or straight from GM for about £65. I fitted one a couple of weeks ago and it took me about 10 minutes including the tray on and off.

[Detta]

Is there an easy way to diagnose if it is at fault without having to drop £50 on a hunch? EDIT: p.s. it's a Tubby.

Edited by Detta, 14 November 2012 - 12:49 PM.

[siztenboots]

borrow one from another vxt

[fezzasus]

Is there an easy way to diagnose if it is at fault without having to drop £50 on a hunch?

EDIT: p.s. it's a Tubby.

In that case it's NGK code OZA659-EE28

Measuring the voltage off the lambda will give you an idea: http://www.picoauto....bda-sensor.html

[Detta]

Thanks guys, as always, legends!

[evo2avxr]

The return of the misfire. Thought the lambda had cured it but after the first trackday of the year last weekend - it came back. Previously replaced MAF, preCat lambda, and plugs. Threatened the car with a visit to Thorney motorsport for testing, but thought i,d take another look today. After much searching - found damage to the wiring going to the MAP sensor. An hour later, soldering iron and heat shrink, and its fixed. Once again - hope i have cured it now. Fingers crossed