I have a 87 GTA w/5.7 TPI. Just recently my tach started bouncing pretty bad, my engine won't rev over +-3500 rpm. I've checked out the coil, which is an Accel Super Coil, it checked fine from what I could tell. I took the ECM, I think it might be factory because it says GM on it, to Autozone they checked it and it checked ok. I looked over the distributor and it looked good. I posted a message about this in the general message board and all it told me to do was to find an origional coil and put it in and see if that solves the problem, or buy a aftermarket ECM that would go good with the power that the super coil is making. He said either one of those should work. I was wanting to get you guys opinion on the whole ordeal since this is the ECM message board and all. Thanx in advance for the help cuz I know you guys will give me some input on the situation. Oh by the way it has new plugs and wires on it.

 

Your ECM is not the problem. A lot of guys suggest this for MAF cars, when the problem is the burnoff relay or a flakely MAF sensor. So they conclude the ECM was the problem, when it was the sensor. What they did is convert to an SD system which doesn't use a MAF sensor, thus they fixed the problem.

If you SERIOUSLY think your ECM is the problem, convert to SD 7730 rather than purchase and an expensive DFI system. DFI has it's place, but not for a "simple replacement" on a basically stock car.

 

87 had integral coil? when you said "it checked fine, from what i could tell" what checks did you perform? just ohmed it out? does your bouncing tach corresponds to a percieved engine misfire? power braking to 2500 in d can produce the same repeatable symptom? this problem started after the new secondary ignition (most common shotgun-plugs,wires,cap,rotor-usually aftermarket)parts went in? that boingy tach thang is usually caused by a bad coil wire-but in your case i think that part isnt needed. bad carbon button, crappy\loose ign rotor\leaving out the small seemingly useless "extra"metal part-the hei ground terminal can really f with your fresh tune job.so can cracked plugs,loose boots,yadayada-it aint the ecm nonono-but if you keep futzin with it, it may need replacing. when the car is idling take a squirter bottle with water in it and spray the wires and coil and related see if you detect more bad things with misfire. 3500 is max no matter what?

 

um, hellllooooo---