alright ive done alot of stuff to try and save this motor. I changed out the plugs, wires, cats, MAF sensor and still my car runs rough and at stop lights i have to give it some gas or it will die it wont stay in park without dying not sure what is wrong i also had the fuel system cleaned out im about through with this motor and wanna throw a carbrated motor in. just wanted to get some feed back on anything i might have missed help me out dont wanna get new motor but thats how it is looking.

Check iac and/or tps. Not quite sure where on an ´86 but on my ´91 they are on pass. side TB. TPS has three wire connector, iac underneath has square four wire connector. Do you have an FSM?

well i dont know what all them abriviations are could you put it in non mechanic terms sorry i know how to work on cars but dont know what them abreviations mean.

I have been having the same problem and just got mine fixed. Let me run down the laundry list of things i have done...

New air filter. New mas airflow sensor, engine temp sensor, coolant temp sensor, fan switch, thermostat, radiator fan, relay and fusable link, plugs, wires, cap and rotor, Msd coil, ignition control module, new computer, Cleaned the throttle body, throttle position sensor, and advanced the timming.

What helped my problem the most because my car was doing the exact same thing would be...
The sensors, ignition control module, plugs, and loosen the distributor and play with the advancement on the timming.

Every thing helped. In the end the three i keep playing with to get it just right is the advance on the timming (distributor) throttle position sensor, and my idle adjustment screw.

If you are running as rough as described start with changing your ignition control module. That may all in all fix your problem.

If you are running any fancy plugs like bosch 2,3,4 or so on... Change them.
I ran the 4's and 2's i fouled them both. There is not much of a contact poing on the top and if you aer burning even a lttle bit of oil you will foul them quickly. I was able to foul brand new plugs in about 500 miles.
I am running the bosch copper core now. That is a really nice plug.

Check iac and/or tps. Not quite sure where on an ´86 but on my ´91 they are on pass. side TB. TPS has three wire connector, iac underneath has square four wire connector. Do you have an FSM?

Oh yeah I did the IAC (Idle air control valve) too. hat is horizontal underneath the throtle body on my 86'.
and yes, it is also in the same place as described above on an 86' as well as the 91'.


IAC = Idle Air conrtol valve
TPS = Throtle position sensor
TB = Throtle body
FSM = ??? WTF ??? lol

Check fuel pump pressure, if that's ok then check for leaky intake gasket, and if you still have problem look for vaccum leaks, has anyone farted with egr valve???? should any of these be an issue they won't break your check book............good luck

An area of vaccum leaks is in the brake booster, do your brakes respond well in a quick near panic stop? If not your booster may be the problem all along, this type of "test" costs nothing and its quik. My 84' had sat for a very long time by a prev owner prior to my owning, it ran like a sick pup, very much like what you have endured. Intake gasket was shot (common) and it still was not "right", so tested fuel pump and sure enough that was weak, after replacing still wasn't quite just right, and finally after thinking stopping power was weaker the it should be, culprit leaky booster, replaced booster & master cylinder. Prev owner went through entire car (to my benefit)looking for solution to problem he never found and gave up. I now have a top running Corvette, runs like the day it was made. Hey......these cars and all their components are a quarter century old or are nearing that, stuff wears out.

Have you ever replaced the fule injectors?

yeah guys thanks for the help im going to check that stuff and just for an update i was told by schuks spelt wrong i know that the fuel filter might be bad changed it out and still running like **** not sure what i need to do but im going to check the things you suggested and for the guy about the injectors im looking at those as a last resort kinda thing not cheap and if i end up getting im going to get bigger injectors if i do that but thanks for bringing it up. i will update next week.

Yo 85c4, Check out thread just started 'bout injectors.............might take you down correct path.

FSM: Factory Service Manual or HELM´S.