Check Engine Light

[silverbullet]

I was getting a code 51 which is prom/ecm. I replaced the ecm and put my stock chip back in the ecm. The car now runs but the check engine light stays on. I checked the diagnostics and now I don't get any codes. The car won't go much over 30 miles per hour. Anybody have any ideas of where to look next?

Silverbullet,

You most likely got a bad ECM. I had the exact same problem...Light would be on but no codes. Went through 2 remanufactured ECM's before I got a good one. My car had only 20,000 miles on it at the time.

Did you have a Hyper chip installed in the old ECM? If you did, did you change the ignition? that might have something to do with your problem, that is if you have a different ignition or carb.

Trent81

[silverbullet]

That is exactly what I am thinking. I am already on my second attept with a remanufaturered ECM. I did have the hypertech chip in the old ecm. I have been trying both chips with no luck. The stock chip shows no codes and the hypertech chip still shows code 51. I did update the stock distributor with the DUI high output coil,cap and rotor and also am using the upgraded ignition module. I have 8mm spiral wound spark plug wires also. Can the prom's go bad?? How do you know if it is the porm or the ecm?