So i have a 86 iroc z28, it has a 305 TPI, ive replaced the fan, temp sensor, Mass air flow sensor, TBP sensors. The car is still over heating and i cant get the idle to down, it is idleing at 2500+. Have no clue what to do or what to look at next?

Do you have coolant flowing? Start it with the radiator cap off. As it warms up you should see the coolant level lower a little and it should look like a river flowing when you look into the radiator. The top radiator hose shoudl also get hot when the T-Stat opens. Id this isn't happening then the water pump or the tstat most likely aren't working right. First guess would be the t-stat is stuck closed.

As far ask the idle. does it surge, or is it steady at 2500? If you turn (slowly) the distribuor cap while it is running does the idle change? Does it stay changed or does it adjust (computer) and go back where it was? If you play with the cap mark where it is now before you start. You could easily stall the car and not get it back running if you don't know this. Also check the throttle cable and make sure its not pulling the throttle open slightly.

To get anymore detailed than this, with out seeing it. A chilton manual will be a life saver for you with this car.

Ok so i check the radiator like you said and when i start the car i start seeing a little fluid run through but then it starts spitting out the top of the radiator cap hole? And the idle go's between 2500 and 3000.

So keep the cap on till you can feel the upper hose heat up. Then open it. That is if the upper hose ever gets hot. I'm guessing that the t-stat is stuck shut.

Did you mess with the distributor to see if you could afffect the idle?

The upper hose does get hot i messed around with the idle a little it would i got it to get down to 1000 it was idleing good, i shut the car off turned it back on and it went back up to 2000 to 2500.

Without getting my hands on it or even my eys to see what its doing I'm not sure what to tell you. Do you have a temp guage on it or is this a light? Last car I had from the 80s was loaded with dummy lights not guages so you never knew what it was really doing.

The idle thing might be the computer. Not sure how advanced the PCM is in an 86. You could have a vacuum leak but that should surge the idle. Like if you floored it, when it came back to idle it would either be way high or drop way low and quit.

Adjusting the Timing On Fuel Injected 1982 - 1992 F-Bodies


Things you will need:
You MUST definitely use a timing light to adjust your timing correctly. You definitely CAN'T do this correctly just by turning your distributor and guessing.
If you just guess when you retard the timing so far that you can't hear any pings doesn't mean anything. Most of the time you won't be able to hear any ping/knock, but your knock sensor will.
The only way a timing adjustment does make sense is: Adjust it using a timing light and hook up a scanner/winaldl and check for knock counts under all driving conditions. If the engine does knock/ping, retard it in 2* increments.
A 9/16" or 14mm open end wrench.
To adjust your timing:


Warm up your engine to normal operating temperature. Shut off your engine.
Disconnect the tan wire with a black stripe that comes out of the harness near the heater box. It is a big weatherpack connector, you can hardly overlook it.
Connect your timing light to the battery (check polarity), connect the inductive pickup of the timing light to your #1 cylinder as near to the spark plug as possible without toasting it with your exhaust manifold/header.
Start your engine and ignore the SES light coming up.
Point your light at the timing mark and check your setting. Watch the timing light's wires. If they come in contact with the drive belt/accessories while the engine is running you could get seeriously injured. If you can't read your timing mark because of rust/dirt, stop your engine and clean it using sanding paper (PITA).
If you still can't read what's on your timing mark: Assuming you are standing in front of your car, facing the engine, the "valley" of the biggest of the v-shaped notches should be zero degrees.
The Vs are upside down when you look at them from the front of the car.
The next peak (pointing towards you) to the left of the big V is 4* advanced, one more peak to the left is 6* and so on in 2* increments.
Accordingly, the one and only peak to the right of the big V is 2* retarded.
Check for the sticker in your engine compartment for the correct setting and compare it to your reading. If it matches you are fine. Proceed with step 10.
If it does not match or you want to advance/retard your timing for other reasons get a 9/16" or 14mm open end wrench and proceed with the next step.
Remove your air cleaner and approach your engine from the driver's side. Locate the distributor hold-down clamp and screw. Insert your wrench in the opening between the ignition coil and the distributor from the driver's side.
Loosen the distributor hold-down clamp just so much, that you can turn your distributor by hand with little effort (Should be a 1/4 to 1/2 turn of the screw, maybe a little more). There my be several other ways to loosen the distributor clamp but this one worked for me. Maybe you can find an easier way, using other tools.
Now point your timing light at the timing mark again and rotate your distributor slighty. Turning it counterclockwise advances the ignition, turning it clockwise retards it.
If you have your setting as desired, tighten the distributor hold-down clamp.
Recheck your setting after that.
When it is still fine, shut off your engine, reconnect the tan wire, disconnect your timing light and disconnect the negative battery cable for a few minutes. This will erase the error code that came up when you disconnected the tan wire.
Reinstall your air cleaner and reconnect your negative battery cable.
Test drive your car using a scanner or winaldl to check for pings/knocks.