rickey383

I have posted on here before i have a 95 z28 i recently bought with blown head gasgets i fixed it then it wouldnt rev right. I have since replaced fuel pump and distributer car now revs but is skipping at idle up to about 2000 rpms if u get on the car hard it dont skip it just has a low rpm skip. any help will help thanks

Injuneer

By "skip" do you mean "misfire"?

rickey383

I'm not sure its a mis fire thats y i didn't say misfire i think it might be the fuel regulator causing the car to load up at idle.

Injuneer

When the engine "loads up" with fuel, it will misfire. That will be the roughness or "stumbling" you feel.

Have you checked the fuel pressure? Check it with the engine off, just after the fuel pump primes. See how fast the pressure drops. If it drops quickly, it may indicate a problem with the fuel pressure regulator or the injectors leaking. Leaking injectors will be more of a problem at idle and low RPM.

rickey383

I checked the regulator as soon as fuel pump cuts off pressure starts dropping quickly checked regulator its working properly. i started UN hooking injectors and found 3 that didn't have no effect on the way the car is running going to check it tomorrow with noid lights to make sure the harness is firing them. Do u know what make the injectors fire. Thanks for any help.

Injuneer

The pink wire in each injector harness connector provides a constant 12V when the key is in the on position. The other wire in the harness connector (various colors) is the ground, and the PCM supplies the ground on that wire to fire the injector. Your 95 has full sequential injection, which allows the PCM to fire the each injector based on the intake event on each specific cylinder.

Make sure you have 12V on each pink wire (key on, engine off). Verify the PCM is providing ground by using a 'noid light. With the harness connector off, measure the resistance across the two pins on the injector - should be in the range of 12-15 ohms.

rickey383

when i put them back on it was still skipping switched the injector wires on the number 2 and 4 cylinders it quit mis fireing imedatly switched back and was not misfireing but still not running right checked with noid light they are firing right so i think im gonna replace the distributer again and put new injectors in it

SoloExceptional

A cracked spark plug insulator will cause a similar issue.

Injuneer

Maybe you have a faulty harness connector - that would be a lot less expensive than a new distributor or new injectors. Worth checking out, if simply moving the connectors back and forth between two injectors significantly reduced the problem.

chevy_dude97

By changing injectors, you could have put a clogged injector in a sequence it does not create a large knock.

More likely did you check the heads for warping? If they are not flat you could have other issues likely intake leaking.

When its missing is there black blue or white smoke coming out the exhaust?