Engine Performance problem
1998 GMC C1500 V8 Four Wheel Drive Automatic 110000 miles
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I have a problem when I go to accelerate some times. It stutters quite badly for a short period of time. It seems to be mostly when you are moving and then depress the accelerator to speed up. When I got it the check engine light was on and the mechanic said the O2 sensors were responding slowly but no check engine light since then. Also, if you put it to the mat from a stand still, it seems to hesitate and then it takes right off. I don't know if this is related but when the air conditioner is running it starts idling rough as well. Thanks for your time.

Rick

Has it been tuned up yet? If not do a complete tune up and clean outr the throttle bore with carb cleaner and a rag, this should help stabilize the idle with the a/c on

Hi Jack. I did change the cap and rotor that was quite corroded. The wires are fairly new and the plugs look perfect. I was concerned about the O2 sensors and it being a problem with the Overdrive as it seems to do it only when it kicks down from Overdrive. I will try some carb cleaner on the throttle body though. Thanks for the reply.

Rick

Check the fuel pressure as well, did you do a fuel filter? very important with fuel injection to have the correct pressure. O2 sensor problems can be traced to low pressure, or a MAF sensor on its way out

Thanks again Jack. I just changed the filter and sprayed the throttle body with cleaner but it still seems to run badly when you first put your foot to the mat. Then after about 20 mph it comes on strong and runs smooth. Weird? Thanks again.

Rick

Try using a MAF cleaner to see if it makes any difference