I have an 1987 camaro with a 2.8L. I replaced the head gaskets and re-assembled. It is a pain to get started now and pops through the throttle body. I pulled a compression test. All cylinders came back the same. 120 psi. I pulled a vacuum test and it slowly drops to 2 from about 10. which suggests I have a vac leak. but, I can't find it. Can't even hear it. either way I don't think a vac leak would cause a backfire through the throttle body. So just to be on the safe side I want to check the injestor loom to be sure all the harnesses are on the right injectors. #1 and #6 can't be screwed up. the length of the wires keeps this from happening. so I either crossed #3 & #5 or I crossed #2 & #4. Just wanted to know if anyone out there had a trick or method to finding out how you can tell which clip goes to it's proper injector.

Please contact me at warlord6six6@comcast.net

Thanx again peeps.

 

A vacuum leak will cause a nasty back fire through the plenum. 10 vac is pitifully low. Hows your vavle lash? is it set correctly? i try takeing the big vaccum line off where it goes into the IAC motor. ans plug that line. that saved me *** in a simalar situation. then get some carb cleaner with a straw and squirt it all along every seal that could be a potential vaccume leak. squirt a small amount to avoid overspray. if the engine suddenly gains rpm, you've found a vacuum leak. but a vacuum leak will definatly cause some serous back firing through the throttle body