I have an 89 iroc with 305 tpi 5 speed. put fuel injection back in car after it was converted to carb car will run but will have to spray starting fluid in throttle body to get to start sometimes,and the idle is erratic. also when i try to drive it it bucks a little and stalls whenever i go to slow down also it backfires occasionaliy.i have replaced iac, new distributor, ecm, plugs, all injectors getting good signal, catalytic converter removed, no air pump, no charcoal canister. i am out of ideas and any help with be appreciated

 

Is the electric factory fuel pump still in it and hooked up? I would think if it had been carbed, the fuel pump was unhooked and an old style pump put in so as not to drown the carb. Big difference in fuel pressure between a carb and TPI.

 

the in the tank pump is hooked up it was running fuel pressure regulator to make it 4 psi for carb. i fixed the erratic idle and stalling turns out it was bad egr valve but wont start at all unless starting fluid is sprayed in throttle body

 

Have you checked the fuel pressure now that you have put everything back to TPI? If so, what is it running? Also, not sure, but I think the 89's still had the "cold start" injector. Could be wrong, so maybe another forum member might know, but if it does, there could be an issue with that????

 

89s didn't have cold start, check the fuel pressure as mentioned and try swapping out the MAF if you can or just unplug it while its running, if it runs worse it's still good. Are all of the sensors hooked up and hooked up right? Might just be your temp sensor, might not, pull the codes and see what turns up there too

 

I was off base with that one. Thanks for the correction stealthroc89!