Feels like engine lag

[robvandam]

Hey guys I have been searching but can't find anything on this issue... I have a 99 GAGT with 117000 miles on it. I know I can't expect it to run like new but there is excessive lag when I step on the gas. I read the post about the transmission problem between 1st to 2nd gear which sucks royally... But I am hoping I can restore power and pickup relatively easily. Any suggestions would be great. I did a tune up about 3500 miles ago which included fuel system cleaner, air filter, plugs, wires, and cleaned out the throttle body. Also when I am on the highway and give it gas to pass someone it will hesitate and fluctuate RPMs from around 3000 to 2800 and make the car accelerate then slow down, accelerate then slow down without and difference of me on the gas. Any help would be appreciated guys. Thanks, rob

[Jchiasson]

What kind of plugs did you put in?
Does it ever go over 3000 rpm in other gears?

[torskdoc]

Sounds like your fuel filter might be at fault.

[gentlegiant255]

I would go with fuel filter also since this seems to be hapenning when you step on it and since you didnt mention that as part of your tune up you did..now my 91 berreta did this and eventually it turned out to be the ecm. Is the check engine light on? 02 Sensor ok? Convertor plugged? Ignition Coils ok? Hope this helps.

[stewartfn20]

yea considering the amount of miles, id blame the cat converter, unless its been replaced before.

[robvandam]

Thanks for the help. Ill change my fuel filter and see if that helps. I would imagine if it was an O2 sensor or something the check engine light would come on but it doesn't. Also it will redline if I want it to but it hesitates at certain points on the RPM band that's all. I was thinking maybe bad gas but it happens with any gas I put in. Its weird....

[robvandam]

Thanks for the help. Ill change my fuel filter and see if that helps. I would imagine if it was an O2 sensor or something the check engine light would come on but it doesn't. Also it will redline if I want it to but it hesitates at certain points on the RPM band that's all. I was thinking maybe bad gas but it happens with any gas I put in. Its weird....

[gentlegiant255]

The check engine light may or may not come on. I have replaced o2 sensors that were bad but didnt trigger the light but set a code in the ecm. The sensor supposed to be replaced every 30k anyways so just do it. Let us know how its going for ya.

[Rockems]

Yeah im thinking fuel filter too... I had kinda the same problems and I had never changed the filter after the 60k miles i had the car and doubt the ppl before me changed it in their 60k miles. After i took it off i couldn't even blow air through it, it was that clogged.

[JfBrshie56]

Have you diagnosed/fixed your problem? I'm having a similar issue with my '99 - http://www.gaownersclub.com/forum/showthread.php?t=89205

Try cleaning out your Mass Air Flow Sensor! It may not do it, but it's worth a few minutes to try and may be a very cheap solution.

[Rockems]

did you try changing your fuel filter? If you havent changed it in a very long time its worth changing anyways