i have a 1988 TBI 305 Camaro that is having all kinds of trouble. First it was oil leaking into the coolant. We changed the gaskets on the intake manifold and corrected that problem. However, now when the car is driving its fine, but once you hit 220 degrees it starts to buck and stall, and then it begins to backfire and lose throttle response. Its a 5 speed transmission (not sure if it means anything) We changes the distributor cap and rotor and ignition module. Timing is right on and all plugs and wires are correct.
This is my fiancé's parents car and we can not figure out what is wrong with it. Any help would be greatly appreciated. I am leaning towards a backed up Cat Converter, but its not red hot or white when the car starts to do it.

 

does the exhaust seem quiter and r u hearing a hissing noise from it. if so that would be the cat. coil going will do what u are talking about to.

 

okay, so, new symptom. i just took the thermostat out and its started its crappy running within about 2 minutes. It will thr and throttle up and then down and sputter and finally die after about 30 seconds. it did this before, which was the original problem. could the coolant now being in the motor right away be leaking in like a head crack or block crack?

 

no hissing from the exhaust. if anything, it almost seems a hair louder and beefier.

 

take the radiator cap off and run it. could be a head gasket or cracked head or block. could be when it heats to running temp and pressures up the cooling system it is leaking into a cylinder. do a pressure leakdown test on the cooling system. see if it holds pressure.

 

a compression test then you mean? Cuz that is going to be a real pain in the *** on this car. Everything is still on it and works. factory original still.

 

Okay... So we got it to give us the codes from the check engine light. Code 23 and 12. Whe chanced the sensor and Code 23 went away. It still shows Code 12, but i hear that that is normal. We are looking to change the distributor tonight to see if that will help at all.

does anyone know when the fan should turn on on this camaro? 1988 Iroc with a 305. factory original.

We are running out of options and ideas here.

 

a leak down test for the cooling system. if u want to do it u will need the pump and gage that hook to the radiator at the cap. u pump it up and leave it for a time and if it drops u have a leak somewhere. at least thats how we did it 20 yrs ago. code 12 is normal. if u have a old distributor that has a lot of play in the shaft it can do what it happening.

 

how do you do the code with the key and is there somewhere i can see a code list or instructions without having to buy the book?