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Discussion Starter #1
Car sometimes won't start, sometimes starts and runs smooth for a while then suddenly tac drops to 0 then back to normal. Seems like maybe it is loosing spark at times. threw a code related to ignition malfuction. Replace the crank position sensor, no change. Fuel pressure was sometimes low so also replaced the fuel pump, still no change.

I have purchased a new ICM for it but can't locate it on the car. I've been looking on the web for info as to the location of this part and I have found conflicting info as to its location including the radiator support, right fender, under dash near steering column and that is doesn't have one at all. The part was listed in the part catalog for the car and I was able to buy one so I am assuming that it does exist on the car but I can not locate it.

Can anyone point me in the right direction here?
 

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What parts catalog did you find it in?? Did you purchase one for a 95?

I believe The 96 V8 ECM has an integrated ignition control module.
 

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Discussion Starter #5
That would explain why I could not locate it and some of the conflicting information I have found online. I guess I am going to need to take the car into the dealership and see if they can isolate the problem. I was hoping to avoid that but at this point I really don't know what else to do with it.
 

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Discussion Starter #6
Well I had the car towed to the dealership today, while there I asked about the ICM hopefully to get a definitive answer and be able to return the one I purchased. The parts guy looked it up on his system and said that it does indeed show one and had a diagram of sorts as to where it was but he could not make it out so I ended up leaving the part with the car and putting a note on the service ticket just in case it does have it and that is the problem. They said they would probably not be able to get to it before Tuesday so now I'll just have to wait and see what they find.
 

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There definitively isn't one, take my word for it. I swapped a 96 computer into my 1994 in part to satisfy my superficial desire not to have an unsightly ignition control module on the shock tower, there's nothing between the coilpacks and computer. Now there is an IRCM which the shop may be pulling up, which maybe they're mistaking for an ICM, but that is unrelated.

To me the symptoms you describe suggest a bad alternator, I'd have it tested before proceeding to throw parts at it.
 

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Discussion Starter #8
Really, I never would have guessed alternator. It is the original alternator but it has always kept the battery charged and never seemed to be an issue though I did read somewhere that it could cause interference with the signal from the crank sensor.

I guess at this point I just need to wait and see what they say once they get it into the garage. Hopefully they will be able to tell me what is wrong.

As for the ICM yes I am pretty well convinced that it is not there and was hoping that the Ford dealer would confirm this but of course they didn't so they left enough doubt that I did not want to return the part just yet.


Thanks
 

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Discussion Starter #9
The car has been at the dealer now for almost a week and they have not yet determined what the problem is with it :(

One thing I had not thought of before is that the car does have what appears to be an after market alarm on it. There is a viper sticker on the window and the siren under the hood definitely does not look to be factory installed.

Could the issues I am having be due to an issue with the alarm?
 

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I had a similar problem recently. Check your grounds, battery to frame, battery to engine and frame to engine. that little problem can burn up an alternator pretty quick.
 

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Discussion Starter #13
Thanks, I thought that seemed odd, can't seem to find a listing for the PCM at rock auto.
Guess I'll call the local auto zone and see if they can get one.
 

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Discussion Starter #14

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ECM is Electronic Control Module; technically, a 1991 XR7 or SC has several.

A PCM, Powertrain Control Module, is just one example of a ECM, Electronic Control Module.

Think "Kleenex" and "Facial Tissue" *grins*

RwP
 

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Discussion Starter #17
Yep I was thinking Engine Control Module and Powertrain Control Module and that they were referring to two different things.
I am definitely out of my element here. I used to do all my own repairs but that has been a while and things have changed.
Most of my experience is on cars from the 60s and 70s. The thunderbird is the first car I have owned with a lot of sensors and such and until recently had almost no trouble with it.

I think I am going to bring it home and dive into it myself again. The dealer wants $850 which seems a bit high to the tune of about $500 above what I would expect.
 

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Discussion Starter #18
So I had the car towed back to my house. The computer was disconnected and laying in the floor.
I ordered a computer and installed it today.
Car runs fine now but the Tac is not registering anything at all.

Could there be something they disconnected at the dealership while trouble shooting?
Hopefully it is not an issue with the computer I just put in.

Any hints on what to check?
 

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So I had the car towed back to my house. The computer was disconnected and laying in the floor.
I ordered a computer and installed it today.
Car runs fine now but the Tac is not registering anything at all.

Could there be something they disconnected at the dealership while trouble shooting?
Hopefully it is not an issue with the computer I just put in.

Any hints on what to check?
If everything but the tac is working, I would doubt the PCM is bad. Generally, when a chip fails, more than one thing stops working properly. But, there is of course the odd exception.

Did you reset the PCM with a scan tool? Try that first. Just remember to not do this right before having a vehicle inspected, or it will fail state OBD checks -- you have to drive it a few miles to clear the emission monitors to make it ready for inspection.

Since you're digging in, if you really want to get to know your PCM, you need a good scan tool (laptop adapter type), a breakout box and a schematic diagram. Be prepared to shell out some dough for the first two of those, but there's no better way to diagnose computer probs -- you can also change parameters (tune) with a good bidirectional scan tool.
 

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Discussion Starter #20
I have a blue tooth dongle and an app on my tablet. It gives me a lot of info but not as much as I had hoped.
The dongle I think is a kiwi II and the app I am using is ODB auto doctor pro.

I have not yet driven the car enough to bring all the sensors online.
After I got it started it was making a new and strange tick/tap that concerned me a bit so I did not run it long before looking for the source of the issue. Turned out to be a frayed belt tapping again the alternator as the frayed portion passed by.
I did hook the dongle to it and looked at some of the data on my tablet. RPMs were reading properly through the app. Engine running smooth. fuel air mixtures look much better than before.

The TAC moves just a little when I turn the key on and a little when I turn it off but other wise motionless.
I checked the connection at the coil pack, tried reconnecting it and tried giggling it while having someone watch the tac but nothing.

I pulled the battery cable before installing the computer, have not cleared it since install.
my app was showing one pending code related to the evap system. I think it was P1443. I haven't dived into that yet but am sure it should have nothing to do with the TAC not working. I suspect something that was done at the garage as being the source, just not sure exactly where to look other than the connection to the coil.

I'll try reseting the codes and drive it some more and see what happens.
 
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