Hi everybody! I just got finished swapping in a edelbrock e-tec 355 into my new 1991 GTA. I used the SDPC Vortec Intake base with stock runners/plenum for now and 25# slp injectors (ls1?). But, that is not the problem. I got everything hooked up and installed (looks great btw) and I've been having a problem with the engine dying at idle (and when moving it cuts out).. I have all of the burning equipment and Moates' 29c040 chip adapter. I made a new program using a AUJP bin and changed a few things like disabling the EGR, fixing the fuel injector constant and changed the fan enable temps. When I have the laptop connected using Moates scanning software, the data stream will cut in and out (sometimes I have to restart the program). When it cuts out while moving the speedo drops to zero and the SES light comes on.. I have tried using the stock memcal and stock chip and it doesn't run very well so I think my eprom is good (runs/idles well when its not cutting out)...

One other thing I noticed is this: When I simply turn the key to on (without starting the engine), the SES light will blink intermittently and the no. 1 cooling fan will occasionally activate then shut off after a few seconds... This is without any scanning hardware hooked up... Curious... BTW, there are no fault codes present and the ECM will blink out the code 12 with pins a and b connected...

I posted this in the DIY Eprom forum as well, but just wanted to see if you guys had any thoughts!

Thanks,
Kevin

 

Check all your grounds... sounds to me like you have a bad ground, or missed one, possibly on the back of the heads.

Good luck!

 

Well, it turns out that is was a bad ecm... After checking all sorts of different things, I finally decided to just bite the bullet and try a new ecm... (the people advance auto reluctantly accepted my old v6 ecm from my old 88 bird as a core ($160 core )) That fixed everything... Now I can actually begin to tune it!! Kind of hard when the ecm keeps cutting out..

Thanks for the idea though, those grounds are extremely important to get correct (and good to double check just in case!)...

Kevin