idle spikes on 02

[kps]

recently my 02 has developed a "spike"while idleing seems more pronounced when up to temp in gear.spike isnt noticeable on tach,is intermittent,and similar in duration to the way my juice module lets you know what power level you have programed.has 30k mi,any ideas?

[madmatt]

w/ a scanner watch desired and actual fuel pressure and fpr%. your desired will remain steady but you actual will gradually decline then "spike" high only to decline again. your fpr% will be doing the same. if this is the case you probably just need a fpr. when you remove the fpr, inspect the end of it for signs of contamination. if contamination is found GM says to replace the pump but I'got away w/ just the fpr, a clean fuel filter and I usually pull a fuel sample to make sure it's clean. I've also seen fuel rail pressure sensors fail and cause this but it's not as common. either way you won't get off cheap and to get to either you'll have to do some diggin'.

[madmatt]

oh yeah... there is a TSB on this and depending on your mileage and dealer, your dealer may take care of it. The last one I did got covered under the federal emissions warr. w/ no deductable. i belive it goes to 8/80. w/ a $100 deduct your covered to 5/100k through factory warr.

[Cornell]

Does anyone have TSB # for the fuel regulator problem. I have an idle spike in the truck and the reflash did not help-I think it made it worse. Any help would be appreciated - just want to point the dealer in the right direction. Thanks much :eek: :eek: