help sr20det wont go past 55mph

[justin240sx29]

I just swapped a s13 redtop sr20det into my 1996 240sx and it idles great and runs fine unti i get to 55mph then its like it hits a fuel cuts it starts bogging and everything. Also i havent changed the speed sensor in the tranny yet b/c the nissan dealership has to order it but could this possibly be the problem because its getting the wrong signal and it thinks im going twice as fast as i really am.

[justin240sx29]

can anyone help me please.

[DJPimpFlex]

So it runs perfect until you reach that speed, like you can full throttle through 1-2 and get to redline with no problem?

[S13NismoStyle]

Yes, you are right, it is your speed sensor. Your car is hitting speed limiter. You need a new speed sensor or check your wiring. You ECU is thinking your going twice as fast as you are.

I had this exact same problem when I swapped a s13 redtop into a 95 s14.

[justin240sx29]

yea i can run it all day long at until i get to 55 it runs perfect idles great i just figured that its gotta be the speed sensor cause Ive already checked everything over but i kinda knew thats what it was thanks for the help though .

[2fast4y0u]

just un plug the speed sensor for now...u will have to do the math for how fast you are going to your rpm-s
or use a gps to tell you your speed. its accurate within a few mph

Done.