hesitation 2-3k rpm

[doctorj240]

I have a s13 sr20det in my s14. For the first month, the car ran great, no problems at all. Over the past 2 weeks however the car has slowly developed bad hesitation problems between 2-3k rpm. When the car is at WOT or even half throttle and up I don't have a problem at all, but under partial throttle it is terrible. Under decel the car runs very rich and I get a lot of backfire. Gas mileage has not been too bad, probably around 20 mpg. Over this period the idle has gotten worse too. What could my problems be? TPS and O2 sensor were my main guesses.

[PMan_S13]

Sounds more like you need some need spark plugs to me. Of course that might be because you are running rich.. fouling out the plugs with carbon.

Do some investigating in those areas and see what you come up with.

[s13sr20chris]

i saw that condition once before and it was a tps. that would be the first place i look. also try unplugging o2 sensor.

[doctorj240]

I changed out the O2 sensor today for an 87 300zx sensor (needed to switch connectors) and it seems like the problem is solved. I

[ILikeMy240sx]

i saw that condition once before and it was a tps. that would be the first place i look. also try unplugging o2 sensor.

If there is anything wrong with the TPS would the ECM throw a code? Also, what's the most common thing that goes wrong with the TPS (the sensor it self? or harnes? etc etc)

Thanx

[s13sr20chris]

the sensor itself is usually the culprit. also it would prob be a good idea to check other poss rich issues. check things like maf ground, coolant temp sensor, and vacuum leaks. the ecm will usually set a code for tps probs. you can check by watching tps voltage as you work the pedal.