Crown Vic PCM coil signal

[tigerpwr]

I changed out the coil on plug (COPS) on my '01 P71 and it ran great for a week until one of the coils blew and I had a misfire on cylinders 4,5,6 and 8.

I checked the connectors and wiring, and even swapped out the coils on the cylinders that were reading as misfires.

Turns out that I was not getting a ground signal for the coils from the PCM. I tested the ground from the PCM harness on the firewall and it looks like the coil that blew took out the part of the computer that controls those 4 cylinders.

My questions:

1. Can I use a non-CNG PCM in my car?
   2. What is the difference between the CNG computer and the non-CNG computer?
   3. Where can I find a computer, or someone that tunes CNG computers?

So far i've found this useful page which I believe is saying the timing is different and the fuel cutoff is different. Any advice, help or guidance would be appreciated.

[karlhafen]

Re: Crown Vic PCM coil signal

I would get the number off your computer(looks something like 1W7A-12a650-AA), and get the correct one off car-part.com for $100 or so. If your car has anti-theft (keys have big head) you will need a factory (or equivalent) scan tool to complete the installation.

[tigerpwr]

Re: Crown Vic PCM coil signal

Thanks, thats actually my part number exactly. Found a couple CNG computers for under $100 about 300 miles away. I'll give them a call Monday

BTW, no PATS on my car...its a P71 (somewhat)

[tigerpwr]

Re: Crown Vic PCM coil signal

Just an update...the problem was fixed back in June.

I bought a used computer for $90 shipped, installed it and have been using only Motorcraft coil packs since. The car seems to run better with the newer computer, but the coil packs keep going out slowly - usually starts with a misfire on a cold engine.

Thanks for the advice!

[larrycng]

Re: Crown Vic PCM coil signal

You might want change all of the and double check the wiring. Make sure they have the "band aid", foam square on them, it will help the problem. Yea, I know it cost money.

Larrycng

[tigerpwr]

Re: Crown Vic PCM coil signal

None of the new coils came with the patch on them...and the old ones disintegrated when I tried to remove them (some had been zip-tied on). I have only seen the coil pack patches on this car - none of the other Fords I've looked at have them. Is it specific to the CNG cars?

Do you have any suggestions for a substitute? It's just an insulator, right? THX

[larrycng]

Re: Crown Vic PCM coil signal

All I can say is they must have changed the design again.

A friend of mine did work in Arizona on cop cars and coils were a big problem. He had replaced enough coil packs that he could lay them out in the form of the Ford "blue oval" logo including spelling the word "Ford" in the logo. Took a picture of the mess and sent it to Ford -- that is when the "band aid" came out.

You might explore the aftermarket, MSD and the like, and see if they have any replacements. If you can find a company called Ignition Solutions, you might contact and guy named Ulf Arens,(yes, he is a tall, blond German), if any one can suggest something, Ulf can. Ulf developed Nology hot wires.

Hope this helps

Larrycng