What computer for this swapped car?

Hi everyone,
I'm finally getting another mustang after selling my previous one. I'm buying a sn95 from my brother. He had a very nice 95 cobra which got wreckec, and he swapped the engine/trans/etc over to a v6 car. Well, maybe a year or so ago he started having trouble with it and it won't start. He thinks it is either the multi-relay box thing or the computer.

I'm buying the car tomorrow for a good price, and it looks like I'll probably need to replace the ECU and that relay box.

Question: What computer will I need and what relay will I need? Will I need the one for the cobra or for the v6? How can I go about figuring out if I need a new computer or not? We're quite sure the multi-relay needs replacing, but not sure on the computer.

Thanks for any help, I'm very excited to get another stang.
 
  • Sponsors (?)


If you want to do some diagnostics, we can help. Tell us exactly what the car is doing.

NOTE: I assume he swapped all the harnesses from the Cobra into the V6 (so you are using a Cobra/V8 CCRM, etc. Otherwise you'd only have one speed functional on your cooling fan, for instance). Note that the following link applies only to V8 CCRM's. That said, I can muddle through the schematics for a V6 if you need it. Look at the number on your CCRM and post it up. That should tell us what you're dealing with.


Here is a nice little synopsis for testing a few relays in the CCRM. I have info for the other relays as well, but only wrote about the ones I considered most important.




Good luck and enjoy the new ride.
 
Thanks a lot guys. I'm going to go look at the car today, as I haven't looked at it closely in around a year probably, and make sure I know what all it has. I believe everything was swapped over with the engine.

I'll try to get the number off of the multi-function relay and the computer, and I'll come back and let you guys know what I've got.

I know he's tried to fix the car a couple times with no success, but he has just been too busy with work to spend much time with it, so he's decided to sell it. I don't think there is much wrong with it, as it was running about a year ago and running really good, then it just quit and wouldn't start again.

I'll be back with more details!
 
Update:
I went and looked at the car today and asked him all kinds of questions. Here is what we came up with:
The car used to run great, then it started having trouble, cutting out and such. He replaced the fuel filter because it was clogged up and he thought that might be the problem, and the car actually ran well for about a week and then just died for good. The fuel pump was dead. He replaced the fuel pump and the pump was working, but when he tried to crank it he heard clicking sounds come from the CCRM. The car has never run since that day, as I have been told. He replaced the CCRM but it still wouldn't start. He has the pump hard wired on a toggle so that the car is definitely getting fuel, and it cranks fine, but it will not start.

The CCRM that he has on there has this number on the sticker on the back of it:
F6SF-12577-AA
Can anyone tell me if that's the right one?

Also the computer says J4J1 on it, so apparently it is the right one.

Does it sound like I probably just need to replace the CCRM? Any way for me to tell before buyone one? BTW, a while before the car died on him the fan went out. That points to the CCRM too right?

Thanks for any help.
 
Update:
I went and looked at the car today and asked him all kinds of questions. Here is what we came up with:
The car used to run great, then it started having trouble, cutting out and such. He replaced the fuel filter because it was clogged up and he thought that might be the problem, and the car actually ran well for about a week and then just died for good. The fuel pump was dead. He replaced the fuel pump and the pump was working, but when he tried to crank it he heard clicking sounds come from the CCRM. The car has never run since that day, as I have been told. He replaced the CCRM but it still wouldn't start. He has the pump hard wired on a toggle so that the car is definitely getting fuel, and it cranks fine, but it will not start.

The CCRM that he has on there has this number on the sticker on the back of it:
F6SF-12577-AA
Can anyone tell me if that's the right one?

Also the computer says J4J1 on it, so apparently it is the right one.

Does it sound like I probably just need to replace the CCRM? Any way for me to tell before buyone one? BTW, a while before the car died on him the fan went out. That points to the CCRM too right?

Thanks for any help.

Two things that I would check. First the stator and second the TFI module. The stator is integral to the distributor and the TFI module is located behind the air filter box on the fender.
 
There's a B after the 12 in the CCRM number. And that is a good one for our cars. :nice:

Confirm FP with a gauge. Also check injector pulsing. The EEC relay (inside the CCRM) could be what is clicking. If so, you won't go anywhere.
The FP and EEC relays are both covered in that above-link if you wanna do some quick testing. Add to that the checking of injector pulsing (use a noid light), you'll have an idea if the EEC relay and PIP (as Toyman noted) are functional.
 
You got it with the injector pulsing. A noid light is the best way but honestly you can use an LED test light. I suppose you could even use a normal test light, though I havent tried it. A noid light is only a few bucks and is a nice tool to have on hand.
 
Update: This is what I was able to find out today.
I did the CCRM tests as described in the link above, and found that 12 and 24 do have accessory 12v, so the EEC relay must be good. Although I don't think it matters because my fuel pump is hard wired, I check 5 and it showd about 9.9 acc volts, which I thought was strange. I check 13 and it had acc 12v, and 11 had constant 12v. So I guess that one is ok too, though the pump is straight wired anyways.

I plugged a noid light into one of the injector connectors and had my brother crank the car over while I was watching. The light kindof blinked/pulsed to the rhythem of the cranks, so I guess that means that the injectors are indeed getting signal from the computer. We pulled one of the plugs out and with it connected to the wire we grounded it and it had spark.

So, apparently the CCRM is good, the injectors have power, and it is getting spark.

Does that mean it's all up to the fuel now?

One time while we were cranking it over we heard it actually sputter a little bit, as if it wanted to start, but only briefly.

Should the next step be hooking up a fuel pressure tester and seeing what I've got? Is there anything else I'm missing that I should test?

Thanks a lot!
 
Was the plug you pulled out wet?

I like the idea to test for fuel pressure. Look for 30+ PSI. Also consider seeing what the timing is set at, especially if the dizzy was removed or played after the car started acting up.
 
It's running! I went out there today and checked the fuel pressure, and it was at 0. We (my brother did me a HUGE favor and helped me a lot) made sure the pump was getting fuel to it and turned the pump on again, which resulted in 40psi on the guage, but there was a lot of fuel leakage going on back there. Upon further inspection we saw that the fuel line was not getting a proper seal with the fuel filter (missing the o-ring) and also the rubber hose between the fuel pump and the line that it connects to at the top of the hanger was worn/cracked and shooting fuel out it's side. We replaced the hose and put an o-ring in the connector to make sure it all sealed up. Turned the pump on, 40psi on the guage, no leaks, cranked right up and idled just fine (considering it's been sitting for so long).

We put the tank back up (a pain!!) and drove it to my house!

Thanks a lot for the help guys! I'll be back many many times with more question I'm sure!