Chimaera 'Farting About' below 2000rpm

[lewis_sharman]

My Chim has developed an odd running problem, in which below 2000rpm at a constant or light throttle, it hesitates and feels like its running quite rough, almost misfiring? It does happen occassionally above 2000rpm, but is mainly lumpy when travelling at around 30 in 4th gear.

It also developed a tickover problem at the same time, In which the revs rise to 1500rpm then drop back to normal at a rhythmic 2 second cycle.

I have cleaned up and re sealed the stepper motor but to no avail

Any ideas?

[2mad]

sc power do a restrictor for the stepper motor to stop the engine from
over revving which is a common problem on chims or it could be an air leak on the inlet plenium etc.

[5.0ltr]

Possible answer here, sorry for the link but it saves typing!
http://www.ridedrive.co.uk/tvr-griffith-fuel-burle...

[jr6yam]

Hi lewis
My chim had similar problem,a new coil
and ECU reset seems to have sorted it.
Also check the HT leads, one of mine split
and was shorting to the manifold.

John

[Chimjunkie]

Hi Lewis, I've done a search into this and a few times it has been said to try loosening the fuel cap and see if that cures the problem. This could maybe point towards the fuel pump theory as well.

[TVR653X]

You may need to clean your stepper motor. Also, you may need to adjust the idle airflow (it should be running at about 900rpm when idling). After that, it may be a misfire or something to do with a coil. If you don't know what to do, take it to a garage though, don't mess your car up!

[s5tuart]

The tiniest leak around the Plenum can cause all sorts of problems. Might be worth checking for leaks?

[lewis_sharman]

Cheers for the replies everyone i will look into it tomorrow. The fuel pump idea seems to fit quite well, when i had the wishbones off it looked really stty, and i cleaned the connections up because they were covered in muck.

I will report back with my findings

[Chimjunkie]

Lewis. JonathanT just posted this in another thread:

JonathanT said:

I had a similar problem - but with occasional stalling. My local traced it down to corrosion on the ECU connector from water. They cleaned up the connector block and it's been fine since then.

Got me thinking that perhaps you dislodged a connection somewhere when you fitted the carpets. May be worth taking the ECU out and having a good look at the connector to see if anything is wrong.

Edited by Chimjunkie on Friday 2nd October 19:52

[lewis_sharman]

Quick update

Had a look at the fuel pump on the car today, and the connections seemed a little dodgy, so cleaned them up quickly and it seems to have cured the problem. I will get the wheel off and do it properly tomorrow though!

Cheers for everyones help