Then lets try and fix it(long) (archive)

Ok then lets try and diagnose this problem. We know that this problem occurs when slowing down and making a complete stop. This problem on my vehicle is intermittently.

First off, the dealer should reprogram your DME to it's previous program. Hopefully the tech. printed out the sheet. I assume you don't have a check engine light since you didn't mention it. Just a few things here that can affect idle air management. Inputs are battery voltage, crankshaft position sensor, throttle position, engine temp. vehicle speed, compressor signal on or off, headlight switch signal, hot film mass meter, and range selection (Automatic trans.) Of course the output is the idle speed control valve.

Now lets do the process of elimination:

I'm sure battery voltage is fine since of course your car is running. *

Crankshaft position sensor is probably the newer design and no misfire fault codes. *

Throttle postion sensor just gives a 0-5v range to the DME and of course the lowest voltage is the LL (closed throttle/idle) signal. If it looses voltage (5v) it will go to a substitute value. In theory it should run fine. Tech should check on that.

Your coolent temp. sensor must be working right since you have no check engine light. *

If your speedometer is working then the vehicle speed sensor is working. Problem maybe is if the processed signal is being sent to the DME to let it know it's at 0mph. That should be checked.

Compressor on signal and headlight switch on signal just bumps idle up. *

The HFM sends how much air is going into the engine and sends a voltage reference signal to the DME. A small blockage can affect it but how does the car drive in part throttle operation? This is something I would check.

Range selection is only on automatics. However, the tech can accidently program your DME telling it it's on a automatic vehicle. I would get that checked.

As for the idle speed control valve. Since it's been replaced, I would check any loose connections on the intake tube including the electrical wirings. Could be a poor installation also.

I've had this problem for months already and has never stalled. Happens like once a day. I dont have any time to check on it though cause I'm pretty much busy with school/studies. Hope this helps.

Follow Ups:

thanks for the input!!!!! imola mikky 12:17 3/26/2000 (1)
- Few more things to consider... Jon Caldito 18:52 3/26/2000 (0)

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