i have a 94 z28 6 speed ...the car idles great but once i touch the gas it has a very bad hesitation and idle ...the hesitation is so bad i cant even drive it to a loca shop to have it checked out ..the items i have replace are ..complete opti , coil , iac, plugs, wire fuel filter ignition control modual pvc valve , pretty much all ignition , not to mention its not throwing any codes , im leaning now torward the injectors ..i pulled each plug off individualy and it never change still reved horible and all ...what else is there? im pretty decent when i come to mechanical im just running out of thing to check and i dont wanna spend anymore money on it and it not getting fixed...any suggestions and info will be highly appreciated

 

It idles great then you say "very bad hesitation and idle" ?????????

Are you saying when you pull the injector clips off one at a time...there is no change to the idle quality??????????????

If you remove an inj clip and nothing changes, you have a dead cylinder. The next thing you need to do is find out why. Fuel spark or compression. Has to be one of the 3.

 

yea man sorry im just getting so confussed becaaused this thing has costed me so much money and it dont even run..im gonna try injectors and see if that helps..thanks

 

Stop playing parts replacement roulette, and start analyzing the problem. A good scan data log might uncover the problem. The software is free, all you need is a laptop and a cable.

Might also help if you explained what mods have been done to the 94, since you have a different car in your signature. Also, when did it start running poorly? Was it ever running good, and if it was, was anything modified just before it started to run poorly?

You indicate its not setting any codes, so you must have a scanner to monitor the engine. What are the values you see for things like TPS voltage, MAP, long term fuel trims, etc? IF you don't have a scanner and can't take it to a shop, how did you determine it doesn't have any codes?

Sort of confusing when you indicate the engine idles great.... but when you pull the injector plugs off one at a time, there is no change in the idle. How is that possible? Is it actually idling poor enough that adding another misfiring cylinder isn't even noticeable? Hard to believe.

Start over.

-provide a detailed list of all mods, changes from stock

-provide a detailed sequence of events starting from the point it was running well, through the vast array of parts you have replaced.

-consider scan software that would allow a detailed record of the sensors and PCM parameters.