Can someone help me diagnose why the V-6 is missing while i'm driving. It seems to smooth out some when I ease-up on the peddle...but when I take off it misses bad. I just got this camaro RS 1989 and am not familiar with V-6's and the EFI. Please help?

 

If check engine lite is on, scan the system & get trouble code & get back to us. If lite is off, give engine a tune up, (new plugs, wires, fuel & air filter), if still bad check fuel pressure.

 

The V-6 runs great at first (about 10 miles or more) then after it gets warm it begins to miss under load. I was told it could be the following....bad o2 sensor, bad gas filter, dirty injectors etc. but I just looked under the hood and found that someone cut and crimped the (3) copper tubes that are coming out of the exhaust manifold. This tells me that this is why the motor starts to miss due to the tubes not being hooked into anything. So now I need to know what they are called and where they hook into so I can get that fixed. I just bought a new O2 sensor but I may as well wait to install it? These tubes must be for the smog control? Where do they go and will this cause havok with the motor? Geeze some ex-owner liked to mickey-mouse!
Please help so I can know what to get.
Thanks!

 

Those tubes in the exhaust manifolds would have been connected to the air/smog pump. The pump injects air into the exhaust when the engine is cold to help keep emissions down until the engine heats up. The smog pump isn't being used after the engine heats up, and having those disconnected/crimped will have no effect on the engine's performance, hot or cold.

 

Thanks for the info. I replaced the O2 sensor and still misses after it gets warm and when I am accelerating (under a load). but this morning I drove it 20 miles and it didn't seem to hardly miss at all. I had put both injector cleaner and Heat into the fuel tank a few days ago and am now wondering if is is now working. But yesterday it was missing badly...

As far as those smog control tubes, I will probably remove them and install bolts to close the holes.

If anyone has any more input that would be great, as I have an appointment tomorrow at the mechanics but would rather save the cash and fix it myself..that is if it keeps missing. I'm an old-school SBC man and am not familiar at all with these EFI's/computer-run engines.

Thanks again,
Marty

 

Those fitting holes are tapered NPT (National Pipe Thread), not SAE bolt threads. Remove one of the fittings and take it to your local hardware store and do your shopping in the plumbing section. You'll be able to find a plug, either square or allen head, that'll work.