part throttle miss, possible o2 problem?
10-02-2008, 11:03 PM
#1
part throttle miss, possible o2 problem? recently my car has developed a very small part throttle miss in 1st and 2nd gear right around 3500 rpms. its is relatively small and can be driven right through, and at WOT everything is normal.
normally when i first start my car, its will surge for about 5-10 seconds then find idle. i always try to let it warm up fully before i drive it and i think i have noticed that this miss only occurs if i dont let the car warm up fully before i hit the road. the miss also has a tendency to stay there, as in if it misses right when i accelerate its going to miss the whole time im driving, if not then itll be fine. i only does it about 20% of the times i drive the car
i have no SES lights or codes and havent had a chance to hook it up to a scanner yet but im leaning towards o2 sensors. the are stock (103k) miles and i have a feeling they arent heating up fully if i dont let the car get to temp before i drive it. plugs are tr6's with under 3k on them and wires are taylors with under 10k on them
any thoughts, guesses
thanks
normally when i first start my car, its will surge for about 5-10 seconds then find idle. i always try to let it warm up fully before i drive it and i think i have noticed that this miss only occurs if i dont let the car warm up fully before i hit the road. the miss also has a tendency to stay there, as in if it misses right when i accelerate its going to miss the whole time im driving, if not then itll be fine. i only does it about 20% of the times i drive the car
i have no SES lights or codes and havent had a chance to hook it up to a scanner yet but im leaning towards o2 sensors. the are stock (103k) miles and i have a feeling they arent heating up fully if i dont let the car get to temp before i drive it. plugs are tr6's with under 3k on them and wires are taylors with under 10k on them
any thoughts, guesses
thanks
10-03-2008, 09:22 PM
#2
i dont think the 02s would cause a miss. ive had situations where they would go full lean/rich and the pcm shoots the fuel trim full rich/lean and the car will bog or die. but as for a momentary miss like that?
i'd try to drive it and find where its consistant. find if its always at the same throttle position. if so it may be high resistance in the TPS. if you have an ohmmeter you can test it. sweep the sensor its full range and watch the resistance. if at any point the meter reads really high resistance that could be it.
you'll know for sure if you find that the miss always occurs at 40% throttle and while sweeping the TPS you find it shoot up at around 40%.
i'd try to drive it and find where its consistant. find if its always at the same throttle position. if so it may be high resistance in the TPS. if you have an ohmmeter you can test it. sweep the sensor its full range and watch the resistance. if at any point the meter reads really high resistance that could be it.
you'll know for sure if you find that the miss always occurs at 40% throttle and while sweeping the TPS you find it shoot up at around 40%.
