Power loss in 4th gear sr20det

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McSmash
Posts: 5
Joined: Sun Sep 03, 2017 1:53 pm
Car: 95 S14
SR20DET Redtop

Power loss in 4th gear sr20det

Postby McSmash » Fri Sep 08, 2017 9:42 am

Ok so I'm wondering why my car falls on its face when I hit 4th gear. I can do a pull from a dead stop and fully go through 1st, 2nd and 3rd no problem. As soon as I hit 4th gear the car does nothing. Full throttle and it's like it's trying to die out. I've read about the speed limiter in the tranny but there isn't one plugged to anything. All the plugs on the tranny are gone.. Anyone have any ideas what's going on?


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centralcoaster33
Posts: 2769
Joined: Tue Apr 05, 2005 10:41 am
Car: 240SX #5-1997
Location: Central Coast, CA

Re: Power loss in 4th gear sr20det

Postby centralcoaster33 » Fri Sep 08, 2017 2:02 pm

Have you considered putting the tranny position sensors back in? If so, use the FSM, if not, then check the FSM. Not all sensors are open/ closed switches. At least one is closed/ open. I think OD and Neutral are the ones that can be accidentally mixed up (similar plugs on the harness and near each other). What I'm saying is, I think there's a chance that it's one of the switches... if indeed it is the speed limiter. That will do a fuel cutout at a certain RMP. It's only supposed to do it in 5th. So, you'd check the FSM to see what signals your tranny should be sending to the ECU and compare that to what they would tell the ECU if none of them provided continuity or open, depending on the FSM. So, you should feel normal driving up to a few grand in RPM's before this flat on it's face, then it could be the top speed cutout being confused. If you're experiencing something different than fuel cutout, like at any RPM in fourth, then I think you have other places to look instead of the tranny position sensors.


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