[Chemko]

My 1983 280ZX will run good for the first few minutes the starts missing and running like crap just falls on its face. I checked all the vacuum line and they look fine. I changed the fuel filter, injectors, spark plugs. One thing that is strange I took the oil fill cap off and the idle increased.

thanks Pete

 

[pilgrim]

Does it start to run badly when the engine and radiator are hot? There's a module on the front of the distributor that can fail under heat conditions.

 

[Chemko]

It only runs good for a few minute before it’s gets to operating temp. What does the module do?

thanks Pete

 

[pilgrim]

The module controls ignition. Rough running isn't usually how it manifests - usually if the module is starting to fail under heat it will kill the engine, then allow it to be started after it has cooled off for a few minutes. "Running like" crap isn't very helpful, but since it's running at all, I'd suggest the module is not the most likely candidate. If you want to test it, have a thermos of ice water handy and when the engine starts to run poorly, pour it on the module (small squarish box, front side of distributor). If it immediately runs better, the module is the problem. (Based on symptoms, not the most likely cause.)

I'm starting to wonder if there's a temp sensor sending bad info to the ECU. I haven't had to diagnose such a problem, but perhaps someone else can help. I suppose one thing you can do is disconnect the temp sensor(s) and see if the engine runs differently than it is now.

 

[Chemko]

The module controls ignition. Rough running isn't usually how it manifests - usually if the module is starting to fail under heat it will kill the engine, then allow it to be started after it has cooled off for a few minutes. "Running like" crap isn't very helpful, but since it's running at all, I'd suggest the module is not the most likely candidate. If you want to test it, have a thermos of ice water handy and pout it on the module (small squarish box, front side of distributor) when the engine starts to run poorly. If it immediately runs better, the module is the problem.

My bet at this point is fuel, not spark. Have you replaced the fuel filter?

Thanks I will try it when I get home. It does seem to smoke a lot when it runs bad. It was ok before I hade the transmission rebuilt I know it doesn’t sound right but that is all I have.

 

[pilgrim]

I had second thoughts and revised my post - please check it again.

 

[Chemko]

Thanks I will try it when I get home. It does seem to smoke a lot when it runs bad. It was ok before I hade the transmission rebuilt I know it doesn’t sound right but that is all I have.

Yes I replaced the fuel filter. When it idles really low the fuel light will come on as well.

 

[pilgrim]

Your '83 has a fuel light? I have a 1983 ZX turbo and it has no fuel light..unless you mean the low fuel warning in the gauge cluster. That light has nothing to do with engine speed.

Are you sure you have identified the light in question correctly?

 

[Chemko]

Your '83 has a fuel light? I have a 1983 ZX turbo and it has no fuel light..unless you mean the low fuel warning in the gauge cluster. That light has nothing to do with engine speed.

Are you sure you have identified the light in question correctly?

Probably low fuel light.
got it thanks

 

[Chemko]

Ok I replaced plug wires, distributor cap, rotor button. It will idle just fine but when you give it gas it will sound like it getting air. I can gradually give it gas and it will speed up missing the will seem to clean out but if I let go of gas and press it again
it will not accelerate and many even die.

if I connect this hose the idle will go down and will miss more.

I took this off and sprayed it out with carb cleaner.