Hey everybody, I new to this site but I hope I can get some help. I just bought a 1987 Camaro Iroc Z28 that has a 305 tpi engine. It had some minior problems that were obvious and I had fixed them however after I finally got it running I found that it idles between 2000 and 2500 rpms. I know it has a vacuum leak how major or minior I do not know but I know there is one there. Also the person who had it before me said that he put injectors in it from a 350 but I do not know if it is the truth or not so if someone could tell me how to id the injectors I would appreciate it. Finally I know this is alot but the tach operates backwards starting at max and going down to zero properly but still backwards. Thanks for everyones help

 

The tach problem may be due to a failed tach filter/signal card (on the rear of the tach) or a failed attempt at rewiring the distributor.

Disregard the tach for now and use a handheld to check RPM. If you have a vacuum leak, that will cause a high idle RPM, especially with larger 22lb injectors from a 350.

The only way to ID the injectors is to read the part numbers on them, which isn't easy with them installed.

 

Thanks for the advice I will look at what you said. The engine does however idle very high somewhere around 2000 rpms. If there is anybody else that could help or add to what is already said I would appreciate it. Thanks

 

Not sure what else you're hoping for here, do what Vader said and you'll get results.

The injector part # is generally cast into the injector body near the electrical connector, so pick one you can see and disconnect it.

 

Here my hint on how to find vacuum leaks, I bought a Craftsman stethoscope for $15 and just took off the 8 in. metal probe and you can hear anything, Including if your injectors are opening and if your valves are sticking, I must of found at least 3 different vacuum leaks on my car, it helped alot.