Okay first off I'm new to the forum I've got a 1985 coupe completely stock except for the basic open air box, & 160 thermo. This i gonna be long but bare with me. A couple weeks ago I performed a complete tune up (new plugs&wires, air filter, oil&filter change) I cleaned all my electrical connections and after it I did so it through a bunch of codes. I unplugged all the connections and plugged them back in and the light went off. And it started to idle very high 1300-1600 and would not go down it would drive but just idle very high. Then i started to cut out and have poor throttle response. It then got worse and if you have it any throttle it would backfire out the intake. I then replaced the MAF. Still the same. I then talked to a mechanic who said it could be a valve issue the heads were then removed and sent to the machine shop to get rebuilt. Got the heads back and replace the head gaskets and every gasket above that (basically rebuilt the top end) after that it still has the high idle and check engine light on. It got very hot and was reading 235 on the dash but looking under the hood the exhaust manifold were glowing orange. I immediately turn off the car and now I'm stumped. So the symptoms are high unsteady idle, getting hot, and backfiring out the intake. Any suggestions?

 

Sounds like a lean condition. Feel each injector for a click. The get a fuel pressure gauge and check fuel pressure. Should be 39 psi without vacuum attached. Will it hold pressure without losing more than 10 psi in an hour? Report back results.

 

I will check that tomorrow I'm gonna replace vacuum lines as well. When you say without vacuum attached do you mean the line from the fuel pressure regulator to the plenum?

 

Yes sir, fuel pressure should always be measured without vacuum, or results are skewed. Check vacuum hose for fuel to. It's possible the diaphragm may be leaking. Injectors clicking is important, and if a wire was mistakenly pulled from injector cap it may not be pulsing injectors.

High idle, and orange condition are screaming lean. Have you checked timing? Disconnect tan wire with black stripe and set to 6 degrees.

 

I have checked the timing I'm not sure on what degree exactly it's set on though, my timing tab is pretty dirty. Do you mean the disconnect ECMThe mark in the balancer is in the bigger of the grooves on the timing tab. I think I will replace the fuel pressure regulator tomorrow as well it can't hurt. Oh and I forgot to mention before it does have a new fuel filter on it and it is on correctly. What exactly do you mean by feel for clicks on the injectors? Thanks in advance for all the suggestions.

 

The notches in the timing tab have different depths. The TDC notch is deeper than the others. This is what you're looking for (6° BTDC):



You need to disconnect the EST connector to set the timing. It's a single pin connector between the windshield wiper motor and the brake booster.

 

Your regulator is specific to the 85 model year. I doubt you'll find one with a spring that will work at 39 psi. if it's not leaking leave it alone, and if you do replace it put on an adjustable cap.

I don't know how to explain a click other than to say put a finger on it and you'll feel it. it is quite different from a vagina spasm, so you should be able to figure it out, or at least let's hope so!

Cliff, great post. OP should set timing just as shown.