1991 ISUZU Rodeo

I am having a small prob with my Isuzu, it has only done it a few times 2 to be exact, it runs good and doesnt smoke, I was driving along and it started to surge and lunge like it was starving for gas, I came home and shut it off, after a while I started it and it ran fine for two days and just today it done this again, I replaced the fule filter and I just need some advice where to look b.wedmore@insightbb.com any help???

Come on aynone???

You were going at a steady speed and the car slowed down. You tried to speed up by pushing the pedal down and then it surged back to speed. Then it happened about ten seconds later. Oxygen sensor. If it was really rough, there could be a computer problem.

This has a Chevy 3.1 MPFI V6. The idle air control is an extending pintle valve on the throttle body that opens and blocks off an air passage in the throttle body in order to control idle speed. I’d start there, as those little buggers are known to get carbon and grease packed in, which causes them to stick. So try removing the IAC valve (top of the throttle body) and see if you can clean it with a can of carburetor cleaner. Spray down the pintle, work at it with a toothbrush, try to work it up and down a little, and reinstall. Hopefully that’ll take care of it.

Other causes can be an EGR valve that sticks open (I think this has the digital 3-port EGR valve) from carbon deposits, intermittent ignition control module problem, fuel pressure regulator, things of that nature. It could also be an O2 sensor, as pleasedodgevan suggested.

If you make an effort to fix it, you should disconnect the battery for 30 seconds or so, reconnect it, and perform the idle re-learn. I think GM even offers different methods of doing this (which is to say, no one seems to have the “definitive” procedure) but the one that always worked the best on my 3.1 Corsica was as follows: take the car for a short drive to get it to operating temperature. Then idle in drive with the car stopped for 10 minutes with the air conditioning off. Turn the car off, restart it, idle in drive for 5 minutes with the AC ON. That should do it.

Best of luck.