Idle Problems cutting out when hot.

[dalecrx]

I have an intermittant fault.

I just bought a TVR chimaera 1999. I used to have one 4 years back a 1994 Chimaera.

Well drove it home everything fine. Then went to start it and it started then cutout. It had been sitting for about 30 minutes so had cooled down abit.

Well its been doing it for the all the time at every junction. Got it home and cleaned the stepper motor as i remembered them being a problem.

Still cuts out. If you hold the accelerator down abit its ok but if you let the revs drop it cuts out.

I did a search on here and WOW it can be a number of problems!! maybe airflow meter, cool water temp, leads, coil, etc etc..

any help appreciated.

I have not been on here for 4 years. Just getting back on the scene!! Really enjoying the Chimaera! Its also got the Griff Wheels on

[blitzracing]

The stepper is the first place to start. If you unscrew it from the plemum, and have a look at the cone, it may well be shooted up. It is possible if you hold the cone in a vice, and rock / pull the body back the whole threaded asssembly will come out. Do it carefully, the motor has to spin to realease the screw thead. It appears that carbon gets into a "keyway" that stops the cone shaft rotating with the motor and makes it sticky. It can be removed with a bit of chrome cleaner and a brush or drimmel. Lubricate it with some light oil on reasembly. If you want it to wind back in (Ie if you cant push it back in), reconnect the unit, line up the keyway with the plastic notch, and power cycle the engine. The stepper motor will wind "in" as the ignition switches OFF. You can get the stepper to wind out in a simular manner, but you have to raise the base idle above 800 rpm to fool the ECU into lowering the idle speed by winding the stepper outwards. No totally recommended, as altering the base idle can cause the ecu to go into fault mode.

[Parrot of Doom]

I had exactly this problem and I thought I'd fixed it, only for the guy who bought it from me to suffer the same thing

I'm pretty sure it was an air leak around the plenum somewhere, possibly the little screw on the top of the plenum (being slightly loose).

[jayzcycles]

dalecrx,if you sort your problem let me know i have had the same for 4 years.the car has been to so many people now that i have given up hope of it ever running right.cheers jay.

[dalecrx]

Im really unsure what caused it.

I drove the chim for about 40 minutes. then stopped. It sat for about 40 minutes with the hood open. Started it back up and it would not idle.

I drove it home and it did it all the way home. Then i cleaned the stepper motor and put it back in and by this point the engine had cooled down quite abit. Started it back up and it still would not idle. I thought sod it so i left it.

Went back out to the Chim later on about 2 hours later and took it out for a drive and its been idling fine ever since. I think its def an intermittant fault.

Now 3 days since the idling issue. It seems fine. It idles perfectly.

I was trying to figure out if it was caused by a heatsoke issue or if it was a electrical fault like the airflow meter?

At the moment all is good so as its working fine then theres nothing to look for ot try and fix the fault. If it occurs again i will update this thread.

[GreenV8S]

Put a tell-tale on the fuel pump, plug a set of NOID lights into the injectors and put them somewhere you can see from inside the car. Next time it happens you will know whether the fuel pump is still running, and whether the ECU is still trying to provide a sensible amount of fuel. If they seem OK then the next step is to install a passove strobe on one/more of the HT leads. (Actually you can do this first if you like, but you won't want to drive around like that so best wait until it has gone wrong.)