Annoying Fault...Rough Running -Difficult to start when cold

[tvrman]

Dear All,

I have had an issue with my car of late. Standard 4.0 Chimaera, which had a full service around 500 miles ago.

The car had an issue starting before the service, but afterwards it was running perfectly. A month sitting in the garage and I go to start it, and it only starts after a while of cranking, and with full throttle, and then it only just catches and gives out a belch of smoke.

On driving the car it is very rough when on steady throttle, fine on lift off or when giving it large throttle. Though on lift off there are no pop's and bangs as it would do normally, and it very 'woofley' as if it has unburnt fuel going through the pipes.

So far I have checked the leads, dizzy, re-made the connectors on the AFM, checked lambda connections, and reset all the relays. The car starts fine sometimes when warm, with difficulty other times.

So I took the car out for a run without the AFM connected, and the issue was a little worse. Reconnected the AFM and took it for a drive, when the idle now started to drop to 500 and below when stopping at junctions.


So I got back home, disconnected the ECU, waited a minute, connected it, and the car ran perfectly, without an issue, as it should, no issue. Started fine, and was running perfectly.

This brings me to the question, what is your take on the issue ?

1) The car has a cold start issue which gums up the plugs and lambda's, which need a drive to clean them, then the ECU reset to clear issues?
2) The ECU is at fault?
3) Other

Any help would be most useful as I intend to take the car to Le Mans on Wednesday, and I would like to fix the car on Tuesday.

Thanks for reading, and help,

Ian

[Waxwork Jock]

It sounds like its over fueling but you need to use a fault code reader to check.
If you need to use one i live in High Wycombe and could run it over and chck it for you this evening. Give me a call my number is in my profile.
Regards Graeme

[spend]

Sounds like it could be running like a dog on the limp home mode (after a fault code is thrown).

You can test that hypothesis by disconnecting the ecu to clear faults, or pulling a sensor to create a fault. Try getting a fault code reader on it as soon as you can?

I would be perplexed if a car ran so badly on the limp map, there would have to be something drastically wrong somewhere.

[tvrman]

Tried the car again this morning, it started fine, without issue. So I assume the issue only hapens if it has been standing for a while.....Annoying.

Thanks for the offer of the fault code reader, I think it best I buy one. Plus off to pick up a set of Estoril's tonight :-)

Many thanks for the offer Graeme.

Cheers

Ian