When and if the car starts it runs like crap. It back fires through the intake, and bogs when you open the throttle. Removed the MAF Burn Off relay and it runs like a champ. Any ideas whats going on? Is there a common fault in the harness somewhere? I've replaced the MAF Relays, fuel pump relay, ECM, ECM Chip and the MAF sensor. With both relays connected it seems to drain the battery. I cant figure out where in the harness this short is. If anyone has any insight, I would appreciate. It has just been one big headache.

 

Have you been throwing a code? I've typed this soooooo many times from my 87 FSM, I'm not doing it again. BUT, pull the fuel pump relay away from the fire wall, and inspect the wireing going into it! What you MAY find like I and others is the insulation has shrunk back (easy fix) causing a short (wires coming into contact with one another). And it does play a roll (provides power) to the maf relay!

 

i did read your post and i did inspect that. the red wire dow have some inuslation that came back but not enough to make contact.

 

It'd be helpful if you could tell us what code or codes your Corvette is kicking out. I had a MAF problem on the 87' and using the factory service manual, a test light and a jumper, I was able to use the troubleshooting sequence outlined in the manual.

The sequence is very specific and following it, I cured the problem. To get the Relays to actuate, you can use a jumper wire that has alligator clips on either end (available at Radio Shack) and ground out the MAF burn-off and MAF sensor relay. Insert a sharp push pin in the alligator clip and puncture the wire that the ECM puts to ground when it decides to actuate it. Ground the other end and You'll hear the clicking of the relay.

Also, while insulation and shorting out is a consideration, there could be a break inside one of the wires. My brother is a master mechanic at a Ford dealership and he'll often wiggle the harnesses and wires to see if loose connectors or internally broken wires are a problem, while the vehicle is running. Once, he had a vehicle that had intermittent problems and using this method he found out that one of the wires in a large harness had got broken internally when it was involved in a major collision. The vehicle wasn't totalled and the whole front sheetmetal got replaced, but no one knew that the force of the collision stretched the harness so hard, that it broke the wire inside, but with no visible damage to it externally.

You can also get an ohmeter on the wire and check each one for resistance. High resistance in a wire can cause misreading at the ECM, as the reference voltages are quite low.