My car for some reason is sputtering and surging once it gets to operating temp. The rpm's will jump around. Ive already tried the TPS sensor, and its not that. ANY IDEAS??

 

Did you de-screen your maf?

 

if its a slight jump in rpms it could be the 02 sensors

 

Have you changed the fuel filter recently? Very cheap and easy maintenance and you can eliminate one possibility if it hasn't been done.

 

When my opti was going, the warmer the car got, the worse it ran.

 

I took out the lt4km and put in the stock one. False knock would cause that would it? I did de-screen my MAF but i havent had problems before this. It doesnt make any sense. It runs perfect until its warm???? THen it feels like it hits a brick wall every so often. Im stumpted. I dont think its the opti. Anyway of testing it besides replacing it?

 

Check your intake elbow to make sure it is not ripped or pulled under. Mine was and it ran like crap until I got a Vortech elbow. Another problem I had was the O2's, not the actual sensors, but my headers had made the wires brittle and they broke, so we sordered them to fix the prob. And of course the hardest to check is your opti, which may be your problem if it has over 100k miles and hasn't been replaced. The bearing on the inside of mine was worn out and I had poor throttle response. If none of these problems, I can't help you.....Good luck.

 

Maybe you could clean your MAF with electrical contact cleaner. Something could have gotten on there inhibiting its ability to measure effectively. If your car is running fine until it gets warm, I'd say you can pretty much rule out the opti. Based on my experience, I would guess MAF or O2 sensor. If the MAF is bad though, it would throw a code. I'm just thinking it may need to be cleaned. The O2's however may or may not throw a code. I keep an extra one on hand to check them if I'm having a problem. If one goes out, it will throw the whole system out of whack in closed loop. Mine started out as sputtering, and then eventually it got worse, carbon fouled the plugs and was running pig rich. The previous post was right about the opti however. Mine too had a bad bearing in it causing the optic plate to waver and mess up timing.

 

I agree with O2s. When your car is cold it's running open loop so O2's are being factored in. When it warms up , bad sensor's will affect driveability.