Hesitates and backfires!

**greenz28** · 05-27-2009, 08:09 PM

Well, I just finished changing the icm and coil as well. It is still running the same. Any other options before I have to dig the opti out?

**lt1truck** · 05-27-2009, 08:50 PM

did you have the icm tested first? i swear this sounds just like a big intake or vacuum leak, i think this because i adjusted my rockers with the engine running and forgot to put the brake booster line on when i went to start it and it had a tough time starting and when it did it would idle all "bumpy" and backfire out of the intake real bad. you should go over every line including pcv, intake boot, brake booster line, pull off the fpr vac line and smell for fuel, maybe the diaphram is ruptured, thats all the stuff i would check before pulling the opti. did you put new plug wires on recently? maybe a crossed one or burnt by the header, it would suck to slap a new opti on and still chase this problem, im not saying its not the opti but throw money and parts at a problem rarely solves it. Hope this helps

**greenz28** · 05-27-2009, 10:14 PM

The plug wires are not crossed, because it was running fine before. I have searched everywhere time and time again for vac. leaks and burned wires. I let the car idle for a while today and noticed that it is running rich. Also after idling for about 5-10 minutes the car died, and was a little hard to start back. I am gonna swap the tps and ks tomorrow with others I have laying around just to rule that out. I checked the fp the other day and it stayed above 40 psi. I really wanna get this problem solved, because I just finished installing my 12 bolt and MT ETs today and wanna try them out.

**lt1truck** · 05-28-2009, 12:52 AM

jeez this is leading closer and closer to the opti, i guess if you have ruled everything else out you could pull the opti and yank the cap off to see it it has any signs of stray spark in there, theres a way to tell you might be able to google it and find out but yeah i guess thats the next step.

**greenz28** · 05-29-2009, 02:29 PM

Just ordered a new delphi opti for almost $300.

**greenz28** · 06-05-2009, 01:27 PM

Just wanted to give everyone an update on my backfiring and hesitating problem. I just got the new opti put in and it runs great now. Thanks everyone.