UPDATE --- worked on the car today. Went out this morning around 11am. Noted in putting the key in the run position that the fan came on and the check engine light (CEL) went out. Started it and let it warm, up the one cooling fan stayed on as it has (was running at high speed) but the CEL stayed off and the car idled normally. Turned it off/ back on about 4 times and the same result as noted in the prior sentence. Checked for codes (jump TEN and GRD) and when I tuned the key to run, the fan stayed on the CEL light went out, and I finally got a code --- CODE 69 -- which according to what I have is the coolant temperature sensor for the fan used by the computer. Got an aftermarket sensor (Standard TX 40) that cross referenced to the dealer part number and put it in. Did the process for clearing the code and started the car. But NO LUCK it would hardley start, would not idle/ popping/ running very rough, kept cutting off, and would not take any gas at all (could not rev up) and no power. The CEL light was on and the cooling fan was running all of the time. Tried for code, jumped the TEN/ GRD --- once in run position fan and CEL light stayed on and NO CODE as I have been experiencing. Put the old sensor back in continued to run rough, fan and CEL light on and tried for a code but did not get one. The car had sat about a week before starting/ running well this morning around 10 am... was cooler in the morning then when I put in the sensor at 2:30 pm this afternoon. Any thing that could impact the running due to the temperature going up a bit in the afternoon? Thought I had it fixed with getting the code but I guess not. Apprecaite any suggestions you may have.

 

This car just does not want to run does it?[:@] So cold this morning it idled and ran fine and CEL was out. Pretty much all back to normal? Then this afternoon it went back to the same old problems. Try starting again when it is cold and see if that is making a difference. Just let it run and maybe rev engine some to see if the warming up changes something. The other thing that might have made the difference could be disturbing the engine harness in the process of changing that temp sensor. While engine is running try to wiggle the harness, connectors, and maybe even tugging lightly on individual wires at connectors for distributor, air flow sensor, thottle sensor, etc. Any place that might have been disturbed by replace of sensor or other place you may have been. Maybe a wire is pulling out or shorting somewhere that was fine untill you moved things?? HOPE. I was beginning to think that maybe cam timing was off but if it ran fine this morning then probably not. The not outputing a code during a forced failure such as leaving MAF or Throttle sensor unplugged is pointing towards a fault in the PCM. fan running all the time is another possible indicator as it is controlled by the PCM. Might even want to try pulling the center console and checking the wires and wiggle test them. If all ok and you have engine running ok when cold then heat up the PCM with a hair dryer and see if that suddenly makes it run rough. Wish there were some better answers instead of guesses!! Sounds like the temp sensor for fan was definitely out at 31k ohms and back to normal but why is fan still running. Faulty signal will put PCM in failsafe and run fan on high all the time. Wiring problemf or PCM? Good luck jimm.

 

Babyhuey, tried sending a PM but dont know if it made it. Found a "diagnostic module" inside the car, drivers side, under dash above left foot. The box is blue, about 7 x7, flat, with two plugs and a bunch of wires to/ from it. Found a bracket had gone into the box and was resting on a circuit board. Pulled the bracket away from the box and started the car. It ran fine for a while (NO cooling fan/ check engine light), but after a while the cooling fan came on and gradually (cooling fan)increased in speed, the car started running rougher got progressively worse, the check engine light came on and ultimately it stopped runnng as the plugs fouled out. The box has a warning on it about "disonnecting wires" and some wires run up the steering column. WHAT IS THIS "DIAGNOSTIC MODULE"? Does it control the airbag? Anything else it controls/ runs especally as to the fuel delivery sytem?

Greatly apprecaite any insight you can provide.

thanks

Jimm

 

Hello again Jim,

Saw your post late last night but did not have a chance to reply. The blue module is the air bag diagnostic module. The wires you see running up the colum would be going to the air bag in the steering wheel center. The module has absolutely nothing to do with the way the car runs but only controls deployment of the air bags and fault monitoring.
However, the power supply to the air bag module is a different matter. It is powered continuously by the 30 Amp EGI INJ fuse in the under hood fuse box which also is power feed to the Main Relay which then powers up the injectors, PCM, and virtually every sensor in the engine.
The air bag module also gets key on power thru the 15 Amp ENGINE fuse in the under dash fuse box. This fuse also supplies power to the main relay coil, fuel pump relay coil and contacts, and all three of the cooling fan relay coils.
Hmmmmm. Am wondering if that bracket may have created a short to ground for one of the power sources and possibly melted a wire somewhere or caused a connector to overheat and create a poor electrical contact condition at the connector. When engine is started that connection is still cool so power flows thru just fine but after running for awhile the increased resistance in the connector begins building up heat that then increases resistance which creates more heat etc, etc, untill voltage is dropped to the point of being insufficient to power up running systems. Just a theory mind you. Still kind of stumped about that cooling fan just coming on and running though. Do you have any wiring diagrams of system?

Sent you a PM too