This post IS not about a Third gen. I just don't know where else to turn. Maybe you guys can help me with this puzzle. I bought a 94 Chevy Lumina with a 3.1 6 cylinder. It has 127k miles on it. I drove it to alabama and back fine. Had it for close to 6 months. But it broke down a couple months back and we CAN NOT figure out what's wrong.
I was driving to work one morning and when i was taking a turn the car just started bogging down. It hesitates horribly when you try and accelerate. The only way to get it to accelerate is to barely push your foot on the pedal and you get a steady acceleration. It starts up fine and run fine in PARK ONLY. Can be in park and run fine just idiling. Once you put it in any other gear it just starts running rough wants to stall when you put it in reverse. Already checked
ignition module.
spark plugs.
wires.
changed the gasket from the upper plenum to the egr thing.
Connected two loose vacuum lines.
fuel pump
catalytic converter.
any help would be awesome.....
thank
jacob

 

Have you checked fuel pressure? Could be as simple as a nasty fuel filter.

Other than that, you checked your cat and fuel pump so I'm all out of ideas :[

 

I would start with fuel pressure as well. Screw on a gauge and check results to what the factory specs say they should be. Check with key on, motor off and check with key on, motor on. "Rev" motor some and see if pressure stays within +/- 5lbs. If you can tape it to the windshield and drive around a bit that can give you a better reading.

If that checks out ok, clean your MAF sensor with some no-residue cleaner. oil and dirt on the MAF can give similar results. Check your air filter too and see if it needs to be replaced.

 

My fuel pressure is fine checked that. Gotta get some more time to get that MAF sensor cleaned. Plus my air filter thanks for the tips ill reply with updates.

 

Even if your "CHECK ENGINE" light is off, the PCM might still be storing codes that might help your diagnosis. Have the PCM checked for codes.

 

okay update. brought the lumina to a shop. they told me it was my fuel pump. i was like okay that is cool fix it then. I pick it up from the shop get 3/4's of the way to my brothers house then BAM! just looses all power and wont start back up. when the mech was trying to find the problem he said i needed a new vaccum harness, but stated that my car will run fine without it being fixed. so now im thinking my vaccum harness is done. but i have never heard of that part. any help again?