Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[JamesV6CDX]

In summary - the 3.2 manual Josh recently bought from simon_omega.

Went to have a look tonight.

Well - it's no surprise the 1-3-5 lambdas are unhappy. It's misfiring like a pig.

Read the codes - it logged a code for misfires on 1, 3 and 5.

Cleared the codes, ran the engine - and the same codes again came back.

Compression tested that bank - and each pot had very healthy compression.

Fitted new plugs, and put a known good coil pack in the 1-3-5 bank from the MV6. No difference at all. Lovely misfire.

I actually think the lambda/enrichment thing is a red herring... caused as a result of the misfire / unburnt fuel / incomplete combustion - what do others think?

My thinking is this.

Because the misfire codes are for the three pots on the RH bank, and on the basis plugs, compression and coil pack are fine -

I am thinking, wiring issue from ECU to coil pack?

Interested in your thoughts 

[Kevin Wood]

What is the fuel trim doing for the 1,3,5 bank?

Kevin

[JamesV6CDX]

What is the fuel trim doing for the 1,3,5 bank?

Kevin

Unfortunately, the bloody ELM would not read the fuel trims 

[Kevin Wood]

What is the fuel trim doing for the 1,3,5 bank?

Kevin

Unfortunately, the bloody ELM would not read the fuel trims 

That's odd. Mine does. What software? Scantool.net?

Cam timing OK on that bank?

Does it run OK from stone cold or still misfiring?

Kevin

[JamesV6CDX]

What is the fuel trim doing for the 1,3,5 bank?

Kevin

Unfortunately, the bloody ELM would not read the fuel trims 

That's odd. Mine does. What software? Scantool.net?

Cam timing OK on that bank?

Does it run OK from stone cold or still misfiring?

Kevin

It would read/reset DTCs, and a few other functions - but generally it crashed out with an error, requiring a shut down of the software, and re-connection of the lead....

I have only seen the car in a warm state... are you thinking possibly it's OK while the lambdas are in open-loop?

[JamesV6CDX]

Haven't yet looked at cam timing - but I did comment it will need to be checked, at this rate 

[JamesV6CDX]

Just to add - I put a jump lead from the battery negative to the engine lifting eye, and re-started the car.

The misfire then immediately went away, and it ran smooth as silk.

But later, I Was able to get it to miss with the lead still connected.

I did start thinking along the lines of bad engine earth.. but needed a multimeter for more tests..

[Kevin Wood]

It would read/reset DTCs, and a few other functions - but generally it crashed out with an error, requiring a shut down of the software, and re-connection of the lead....

That's odd. I find it quite stable.

I have only seen the car in a warm state... are you thinking possibly it's OK while the lambdas are in open-loop?

Yes. Cold running takes the lambda loop out of the equation, of course.

Did it get any better / worse when you cleared the codes? (this also resets the block learning on this ECU)

Kevin

[Kevin Wood]

I did start thinking along the lines of bad engine earth.. but needed a multimeter for more tests..

Does sound like a possibility. I would do a thorough visual inspection of the engine-to-chassis strap and the ground to the engine management loom (can't remember where it is on this engine).

Kevin

[JamesV6CDX]

I think it was moreso my laptop - the OS is unstable and it needs a rebuild. Everything crashes

It didn't seem any different after the resets.

[JamesV6CDX]

(can't remember where it is on this engine).

Kevin

3 wires bolted on the rear of the 2-4-6 head?

Visual inspection was hard at the time - very dark etc - but this will need to happen. There are lots of traces of wiring being cut (and not insulated) around the battery terminals etc, I am guessing plod kit - it needs a good tidy up really, but nothing drastic.

[feeutfo]

at the oxford meet, TB said to check the wiring to/from 1,3,5 to ecu, and i believe it was similar response to a thread Simon posted on same issue... as i recal..?

have also seen other threads where ecu was fubar due to some donkey (at Mr Clutch in slough, in one case) trying to connect the battery up backwards, or so the story went. Similar symptoms.

Not sure if TB suspected lambda at some point as well? or was that on another car, there where alot of facelifts at the oxford meet, oh, and a Rover.

[TheBoy]

I saw thise one at Oxford meet, and after a moment of suspecting wiring to 1/3/5 coilpack (or associated earths), went back to thinking lamda related.  I never saw the car cold, but going on the symptoms that were described that it was fine until it went closed loop.  Also fine at WOT judging by the tyremarks up the road

[Kevin Wood]

Might be worth a try with that Lambda unplugged on that basis that that's likely to force it open-loop, I guess?  :-/

Kevin

[JamesV6CDX]

I'd agree with that, Kevin