Hi I'm new to the forum and need some help. My car is a '91 with the L98 and automatic. The car has 10,000 miles and is garaged (non-climate). I went to go start the car and the electric fan came on, I shut the car and it did it again (key in the ignition, turned all the way but not started) I tried again and same thing. I tried one more time but took the key out of the ignition put it back in and it stoped. The car ran fine for 5 minutes and then the service engine soon came on (flickering) and the car started hesitating when I would step on the gas. I was able to get the car home. The next day the car started fine but died a block away. Took 5 minutes to get it started.
I hooked it up to an auto x-ray (obd-1) and pulled up a tps sensor voltage too low. Replaced the tps ran fine for 5 minutes and service engine came on and started hesitating again. A couple days passed and did some reading. Hooked up auto x-ray and cleared the codes from the ecm and scanned again and pulled up tps volt to low, coolant senser to low/high, and a map to low. :confused: I figured the coolant senser needed replacement because the sensor was surging back and forth but whats with the tps and map? Do you think it could be the ecm? I think the car has an aftermarket chip in it. Do you think it went bad? Is there a way to test the ecm? The project for tommorrow will be to find out if it has the chip. Thanking you in advance for any help possible. Frank

 

Sounds like the ECM is going into Limp Home mode to protect the engine, which brings on the fan(s).

The ECM is tough to test except by substitution; though it IS responding to the AutoXray.

You might recheck all important connections, to the TPS, the MAP and especially to the ECM. Also check the supply voltage to the ECM.



[Modified by 65Z01, 6:09 PM 10/10/2002]

 

that sounds about right.if you have an original chip swap it and see. Im sure someone in your area can help ya with this. try posting in the ecm section.

 

What was the voltage reading that you set your replacement tps at? You do need to adjust it when installing, if you don't you will still get a code set and also the bad hesitation. The first one I put on, I just installed it no adjusting, the car started up fine, and as soon as I took it for a ride I noticed it still hesitated and the check engine light came on :confused: . I posted my problem here, and 65Z01 had the way to set it(adjust), I followed his instructions and it was all ok(as far as the tps was concerned!) after that. :cheers:

 

Check your charging system....battery and altenator.....do you see any problems????

Let me know...as I had the same problem...and these items were why...

We are all new to problems.....
tony :D :D :D :D


[Modified by oldace84, 11:55 PM 10/14/2002]