I have a 1985 Camaro IROC-Z with a 350 TPI bored out 0.030 over, I bought it from a guy that said he did all the work and I'm finding out over the years that he basically did nothing to it, and has no access to the people that did do the work... I do know that the TPI was off of the original 305 engine... Right now, it's running like it's on 6 cylinders, the # 2 and # 7 cylinders are cold, but they're getting spark and fuel... It's obviously out of time somehow, but I noticed after I time it (set at 6 degrees advanced base timing and then the computer should add the advance after that) that the advance is really low... It should be advancing to around 30 or so degrees at least, and it's only at 12-14 for some reason.. It's has a new accel hei distributor w/computer advance, new coil, new fuel pump, new adjustable fuel pressure regulator, new head gaskets (the heads were resurfaced), no vacuum leaks, good equal and consistant compression on all cylinders, the fuel injectors are all spraying good cone shapes, I pulled the exhaust off awhile ago incase I had a bad cat and it's still off, it has an egr blockoff plate on it, etc... Please, if anyone has any ideas what this could be, I've been having a hell of a time trying to figure this out... Can a bad ground strap cause this? Because, I noticed the timing light doesn't flash on a consistant basis when I use it, it's very erratic... Also, does anyone think that my timing chain jumped? Or could it be as simple as being a tooth off on the distributor? I have no other ideas... Thankyou for your help

 

Verify the firing order (plug wires plugged into the correct holes in the distributor cap).
If they are right you will have to check the wiring to the injectors (2&7) for opens.
If the injectors are firing, you will have to check that the cam lobes for those cylinders are not "round" (worn down until they just barely open the valves).

 

Thanks for the reply Supervisor... I am sure about the plugs/firing order, and also the injectors are all firing, so there is no open... But I am worried that the lobes are rounded off... What I did notice today though (when I was checking to see if the distributor was a tooth off - which it is not...) was that when feeling the #1 cylinder spark plug hole for compression, it was actually sucking my finger in at times... does that mean that my timing chain jumped and the cam is now off??? or is that the lobes being rounded off?

 

Oh... One more thing... I fixed the grounds on the back of the heads today, and the timing light is no longer erratic.. But I still have the same problems with how it runs... I have no ideas at this point other than the timing chain and cam lobes being rounded off... Both of which suck...