hey, I have a 88 iroc 305 tpi stock. It was running fine then i started the car and it would not stay running unless i kept the r's above 4G. I had to drive it home in second gear. When i went to park it, it went back to running fine. I came out the next day and it was running bad again. Almost feels like the timing jumps way out when it is running bad. I think i might have a injector sticking. What do you think and if it is what is my best way of going about fixing it?

 

Any codes?

 

sounds like fuel cut, may be debris in the fuel filter or fuel tank. could be a fuel press reg acting up. hard to diagnose these kinds of problems. if it were just one injector, it would be more like an engine miss.

 

thanks, Ya it is much worse then a miss. It is almost like it is getting to much fuel because it will only run at such high rpms if i try to bring it down below 3000 it just shuts off and no codes.

 

check your induction system, see if there is crap in there choking the flow of air. does the car burn oil? may have a cat starting to plug up.

 

no air blockage, and car does not burn oil, just a little smoke on startup. Would a cat give u such a on off problem?

 

when a cat plugs up, your car will runn like crap, usally it wont run right until its removed or replaced.

 

so it is not a cat and it would have to be multiple injectors to create a severe problem like the one i have. Is there anything that would produce a drastic change in the air fuel mix? I am at a loss as to what could make it run so bad one second then swich back to running fine. I dont belive it is ignition because most parts are new coil, cap, roter, wires, plugs, and i never have a backfire or any bad timing indicators when it is running bad. At least this is not my primary car :-)

 

You really need someone with the skills and tools to properly diagnose it. Guessing over the internet on a vague set of symptoms is less than a good way to get it fixed. That said, I'd guess it's still the ignition system. Bad pickup coils and control modules are common problems.

 

Test the fuel pressure. Monitor the fuel pressure AFTER the pump has shut off. It should hold pressure for several minutes. If not, the fuel is either leaking back through the pump checks (not a problem), through the FPR back to the tank (not a serious problem) or through injectors or the FPR diaphragm (more of a problem).