still got idle problem and running rich, any ideas?

[tvrlee]

Had an idle problem for a few days now, still not got to the bottom of it and wondered if anyone had any ideas? the story so far:-

Serviced car about three weeks ago, all fine then car started idling very fast before setlling down after 15-20 seconds.
I put the car on a rolling road at Triton motorsport, Hurn Airport which showed it had 206bhp and that it was dumping fuel at 4000rpm, hence the bhp being a bit low, andy at Triton suggested that it was either AFM, temp sensor for ECU or fuel regulator, but probably temp sensor as the coolant had recently been replaced.
So i changed the sensor, reset the ECU, no difference, i then checked the settings on the AFM and throttle pot with multi-meter, both had correct settings.
After reading several threads on here i disconnected the stepper motor, this did make a difference in that when i started the car it didnt rev high and when pulling up the revs went straight to normal tickover without any problem, the car is running very smooth as well.
The tickover was still slightly high at around 1000-1100 rpm so i adjusted the base idle and had to wind it right down as far as it would go to get it down to 950rpm.
So now the car is running with no stepper motor and the base idle screw wound down as far as it will go, it also smells as though it is running rich but havent had a chance to check it.

Is the above normal or am i missing something? is there anything else i can check or should replace?

Any help on this would be appreciated, i am looking to get the CO checked and air/fuel mix checked over the next few days.

Lee

[dwgriffith]

With the stepper out of action and pipe to it plugged the idle screw should be capable of stalling the engine near fully closed. If you haven't plugged the pipe to the stepper then it's current position is letting in air, if it's plugged then you must have an air leak to the plenum area.

[nicktowe]

I had this problem, and the cure was simple but you have probably checked this already..........the multiplug to the AFM was not pushed home properly (workshop must have un plugged it to get at the manifold gaskets).

[im]

nicktowe said:

I had this problem, and the cure was simple but you have probably checked this already..........the multiplug to the AFM was not pushed home properly (workshop must have un plugged it to get at the manifold gaskets).

Nick: YHM

[gadgit]

Nice looking car Lee.

Right, after checking every connector you can find, and no joy, I'd start with the temp sensors, cos you say it runs fine from a start. we are assuming its overfueling here, cos you say you can smell fuel all the time, yeh!

Coolant temp sensor, or fuel temp sensor would be my first calls for price!
Provided they are not to bad ££ get them both.

If that does not cure it after you have tried cleaning every connector as well you will be reaching the point of going to a dealer, or spending out some more money. Its your choice then.

Just remember that the ECU relies on all the imformation from all the sensors to adjust the fuel amount.
yours appears to me to think its still cold when its hot.
Also I don't know what injection system you have on yours

Coolant temp resistance..... -10c 9200 ohms
0 c 5900
+20c 2500
+40c 1180
+60c 600
+80c 330

Fuel...........................reads the same as above according to the bible!

See how you get on with that for now??

[tvrlee]

Thanks gadgit,

I have checked most things, AFM, throttle pot, stepper motor etc and replaced the coolant temp sensor, i having the exhaust gases checked on tuesday to see how rich it is running and spoken to Richard Fisher(PH'er) who hires out the ecu code readers, which should show up what teh problem is.

Reading through the bible it could be anything from lamdba sensors to afm to fuel pressure regulator or even the carbon can!

I'll let you what happens and thanks for the help so far!

Lee