So I bought a 1996 camaro 3800 II from a guy at work. He lent it to his brother when he went on deployment and apparently his brother trashed it. So he went out and bought a 2011 mustang gt (traitor) anyways he just left it sitting in the parking lot at the barracks to just rot. So seeing a camaro just sitting there covered in 9 months worth of grime and leaves and just being ultimately neglected, I offered to take her off his hands for a steal. 200$ finally got it jumped and running because the battery was dead and let it idle for a while as it burned off all the crap in the exhaust. Now here's the thing. I turn it on and it starts beautifully....well it starts right up. Few squeaks but..whatever. The engine will settle at around 1100 rpms and then the car shakes as the idle goes down like its about to die and then it recovers, throwing the needle up to about 1500 and then it bobs up and down until it settles at 1100 again and will stabilize for a while then repeat itself. Sometimes its ok, sometimes it's really bad where the car is shaking. When I accelerate it stumbles and lags and then gets up. The ingine runs fine above 1500 Rpm's but will either shake or do previously stated process. I took it out to drive and it has little to no power at all. Had trouble getting it above 40. Every time I accelerate it lags and the car shakes. Until it picks up Rpm's. Now I was using the old gas. I added octane booster and cleaner to maybe help a bit. There was a half tank left and I had nowhere to legally put the siphoned gas on base without getting my *** chewed. I checked for codes and it throws P0102 for the MAF sensor and P0300 for a misfire. But only occasionally does the misfire start flashing while I'm driving. I cleaned the MAF and it acts the same plugged or unplugged so the shaking or loss of power is result of something else. I checked the pcv and it's rattling, so i think its good. even though there was a oil stain at the bottom of my MAF screen. This weekend I'm going to remove the throttle body and clean the S*** out of it, change the fuel filter and put premium fuel in it. I'll see if I can pick up a cheap maf but I really don't think that's the issue. I'm also going to run a compression check and check the plugs. Besides that if nothing helps I'm lost. I was told that the car had the lag issues before he gave it to his brother so that isn't new. And someone told him there was an issue with a jacknifed exhaust? Would that be loss of power? Any other ideas would help and I'll post an update once I do my thing this weekend. Thanks!

 

I have noticed that if I start the 3.8's with a battery that is not fully charged, it does as you say, idles down and then surges to around 1500 rpms and will do this until the battery gets a decent charge.

As far as the misfire, it could be the plugs, wires, coil paks or something as simple as a crossed plug wire.

The stumbling is more than likely due to the engine misfiring or could be from low fuel pressure.

A few common things you will need to check, air filter, gas filter, gas regulator pressure, make sure the exhaust is not plugged by critters building nest in it from sitting, vac leaks on the vac lines. Might want to flush the radiator and change the oil and filter.

Congrats on the car and good luck.

 

If changing the plugs, wires and coil paks do not help, the other 2 things that determine the timing of the 3.8 is the crank position sensor and cam sensor that may or may not throw a code. If you haven't already, pick up a repair manual for it at the local auto parts store, they help out with alot or if you really want to get into it, ebay has the official repair manuals.

 

Alright so I fixed it. Bad coil pack and it was only running on 4 cylinders. Runs like a charm now EXCEPT: when accelerating it feels like it has lag, like when you drive a car with a turbo it takes a second to actually power up, and the engine sometimes stumbles between 50-70 mph and during WOT. Could that be the clogged exhaust the previous owner said might be present?

 

I would have the exhaust checked if you think it is plugged. How much flow can you feel coming out the tail pipe? Also, might want to test the fuel pressure regulator to see if it is holding pressure.

 

I tested it this weekend when I was trying to get it running, it's within limits. And there's a good amount coming out the tailpipe. How would I check it?

 

Exhaust pressure is usually tested by removing one the upstream O2 sensors and screwing in an exhaust system pressure gage. Pressure should be less than 1.5 PSI @ idle, and less than PSI @ 2000 RPM. If pressure gradually increases while the engine is running at a steady 2000 RPM, it is an indication of a clogged exhaust system. Possibly due to bad cat, bad muffler, squashed exhaust pipe, etc.. All test are done with transmission in neutral, as placing the engine under load will greatly increase the amount and pressure of the exhaust gases.

 

Id check for any damage under the car, looking for a pipe or other exhaust componets that may have been damaged.