ECM help
 

Ok here is what i have. I am running a 5.0 from a 1990 lincoln town car and i have been wanting to upgrade the ECM unit to a Mustang one. I got one from a 1988 Mustang with speed density (which is what i have on my motor as well) and when i plug in the ECM it runs and idles, but it does not run good at all. I was talking with a guy i kow about it, and he said it is because the firing order on the Mustangs is different than my engine. I thought i just had to left the computer learn about the car. Can anyone help me with this?

I think the guy you spoke to was correct.

Ok, it makes sense to me. Now here is my other question. If i go with an e303 cam and change my ECM to the Mustang ECM will i be ok then?

If the firing order is the problem a different cam wont help any the firing order will remain the same.

I believe the only way to make it work is to do some rewiring

I thik i finally figured it out. the internals on the engine are the same. As far as the crank and pistons, but the ditributor is differently numbered as well as the cylinders. So i could change my distirbutor and then put in the Mustang ECM and things should run correctly. I think that is my new theory anyway. Thanks for your help guys. I appreciate it!!

The cylinders are numbered the same, it's just the firing order that's different. You don't need to buy anything new or different, all you have to do is move 4 spark plug wires on the distributor cap. Trace the wire going to cylinder #5, and unplug it from the cap. Next trace the wire going to cylinder #3 and unplug it from the cap. Now plug each one in the other ones old place on the cap. It's easy because they are directly across from each other on the cap.

Now do the exact same thing to the wires for cylinders #4 and #7.

That's it. You're done.

ooo man, thanks!!! That makes perfect sense!!

Ok guys, i put the Mustang ECM in and switched #3 and #5 and #4 and #7 but the engine is running like it is missing. If i put the Spark plug wires back to normal and put the old ECM in it runs great. Is there something i am missing? Thanks for the help

Aaron

anyone??

Sounds like there is a problem with the Mustang ECM.

Re: ECM help
 

You might want to reread this thread.. http://forums.mustangworks.com/showt...threadid=42118

The 89-93, and 88 Cali, cars have the mass air units in them. There is a small wire in the unit that heats up and lets the cpu know how much timing and fuel the engine needs. Speed density does not do this. It has a set program. I do not know if the non-HO motor has the same cam and other specs as the HO motor but I suspect not. I suspect that is your problem. You could look up the specs of the cam and what not, maybe I'm wrong.

If you want to get this thing running right with the speed density.. the right person hasn't come along yet. 88workcar is the speed density man around here.

Re: Re: ECM help
 

Maybe I read it wrong. I thought he said both his engine and his ECM's were Speed Density?

Yeah, the engine is out of a 90 Lincoln. He is adding the mustang ecm to gain performance and I guess one of his friends told him he could had heads, cam, intake with the mustang ecm and the computer would compensate. I told him he needs mass air to do that, not speed density.

Maybe I need to clarify what I was trying to say. He is trying to use a HO cpu on a non-HO motor.

I thought I was getting that across but sometimes I have a problem getting 2 pages of thought into a short one paragraph post. I try to keep my post short and to the point, usually.

Unless I'm losing my mind... the speed density mustang 5.0 had an HO motor.

Re: ECM help
 

The problem you are having is that the firing order on the motor you have vs the HO motor are different. Two things change to change the firing order. The valvetrain and the ignition.
You changed your ignition, however the valves are still moving at a different firing order. You have to get an HO cam in order to change both components of the firing order.

Re: ECM help
 

Good advice Jimmy, but I think he's got it fixed by now...You can view the date posts were posted in the top left hand corner of their original post..