Diag help

[Nefarious]

My engine's not quite running right after I replaced the HT leads, plugs and coils and cleaned out the injectors, so I plugged in the laptop to see if it would give me some clues.

Both throttle readings remain idetical throughout.

At idle, the right bank shows an adaptive near zero and an injector duration of 2.1-ish ms, while the left bank has an adaptive of -30ish and a duration of 1.7-ish ms.

At c.3k rpm, the right bank moves to an adaptive of +30ish and the left bank moves to near zero.

In the absense of any better ideas, my next step is to:
1) check all injector and plug connections
2) pull all the plugs to check for fouling
3) swap all the injectors left-to-right and see if the symptoms switch.

Any clues ahead of time would be most appreciated...

[BGB autosport]

Have you reset the adaptives since doing the work?

[Nefarious]

Nope. Not touched the t-pots or throttle bar or anything - just purely replaced the electronic bits and cleaned and replaced the injectors.

Leads me to one (or more) of the following conclusions:
1) I've not plugged everything in right
2) I've buggered one or more of the injectors in the cleaning process
3) I've re-distributed unevenly flowing injectors
4) One of the new components is faulty

[GreenV8S]

The symptoms seem to suggest a throttle imbalance causing one bank to flow less air than expected for the throttle pot reading.

I'm curious to know what you mean by this, though:

Nefarious said:

cleaned out the injectors

[Nefarious]

GreenV8S said:

I'm curious to know what you mean by this, though:

Nefarious said:

cleaned out the injectors

Removed all injectors, placed thim in an ultrasonic bath, with ultrasonic cleaning fluid, ran the machine for five minutes, took them out and dried them, renewed all the o-rings, replaced them in the car (although not in the order they came out, as I forgot to note that).

[Steve_T]

Have you looked at whether the throttle percentages move in step? I'd suggest you may have a mechanical issue with slop in the linkage. It doesn't have to be much because the arms on the throttles starts from a near horizontal position, exacerbating any problems in synchronising the two banks.

Edited by Steve_T on Monday 12th October 13:02

[Nefarious]

Steve_T said:

Have you looked at whether the throttle percentages move in step? I'd suggest you may have a mechanical issue with slop in the linkage. It doesn't have to be much because the arms on the throttles starts from a near horizontal position, exacerbating any problems in synchronising the two banks.

The throttle numbers at the top are identical at 14.something and stay near-as-damn-it identical for any throttle opennings.

The thing that's throwing me, is that the problem appears to be over both banks (or something that effects both), and given that it's only electronics and injectors that have changed - what could cause a problem on both sides??

Edited by Nefarious on Monday 12th October 13:42

[JensenA]

Nefarious said:

Steve_T said:

Have you looked at whether the throttle percentages move in step? I'd suggest you may have a mechanical issue with slop in the linkage. It doesn't have to be much because the arms on the throttles starts from a near horizontal position, exacerbating any problems in synchronising the two banks.

The throttle numbers at the top are identical at 14.something and stay near-as-damn-it identical for any throttle opennings.

The thing that's throwing me, is that the problem appears to be over both banks (or something that effects both), and given that it's only electronics and injectors that have changed - what could cause a problem on both sides??

Edited by Nefarious on Monday 12th October 13:42

Identical Throttle Pot readings?
If you have a faulty Throttle pot, then the ECU will take readings from the working TP, and apply that to both banks. Disconnect each of the throttle pots in turn, ie only one is connected, to determine if, and which, is faulty.

[Nefarious]

Not sure they were absolutely identical (will double check when I'm back at the garage), but this is definitely a good line of enquiry, as it would explain how a problem from one side could manifest itself on the other side.

I'll be annoyed if it is a faulty t-pot though - I only changed them both 12 months ago. That said, both t-pot plugs came off when I took the injectors out, so maybe one hasn't seated properly when it's gone back on.

Edited by Nefarious on Monday 12th October 14:57

[Nefarious]

Right - still having problems, so any further advice most welcome...

The throttle reading weren't absolutely identical, just very close, but I tried unplugging each of the t-pots anyway. Other than making the MIL light come on, it made very little difference. I also tried swapping the t-pot cables, but that made no difference either.

I also reset the fault codes and adaptive maps, but it quickly moved back to exactly the same pattern again (left back clearly running rich, as the Lambda value stayed around one constantly until the adaptive went strongly negative again).

At this point I'm pretty much out of ideas - when I'm back at the weekend, I'll try the checks listed in my initial post and failing all that will just try setting the throttles up again from scratch. Can't help the feeling that that's barking up the wrong tree though...

[Steve_T]

Think I missed something obvious. Have you checked that the lambda sensors connected the wrong way round? IIRC this is a common way to end up with the adaptives you reported initially where one bank is at max compensation and the other is untouched. Have a look for some other threads re swapped lambdas.