Car cuts-out at 5k in 5th gear(fix?)

[Dustin240]

Car cuts-out at around 5k in 5th gear. The car revs to 6k fine in all other gears. Its a 89 with a ka24et. Is there a 5th gear sensor I can cut off to fix it? How high can a sohc rev with out problems, w/built bottom end?

[S0lid_Snake]

lol thats the 5th gear speed limiter in the ecu, the fix is to unplug some wires, im not sure what ones though so you need to search, or send your exu to jim wold tech and they will remove the limiter

[Dustin240]

Just found it in the (Great Info Here, LOOK HERE FIRST ) post.

[Dustin240]

Is there a way to still have the 6k rev limiter (SOHC)but no speed limiter?I could just get a after market rev limiter, but if I do that is the max safe rpm for SOHC, built botom end, stock head?

[NateDogg]

Only way I know is to tune your ECU.

[CleanSfourteen]

I have heard of a few solutions, apparently the speed sensor wire from the transmission goes to the speedometer, it then goes along another wire to the ecu to report the speed. (i haven't confirmed this with a wiring diagram, but if true, it should work) simply cutting the speed sensor wire between the speedometer and the ecu should get rid of the top speed limiter.

The easiest way i know to remove both is using an AT ecu, my automatic transmission is as good as history, but the ecu is staying because it doesn't even know that a 5th gear exists. When you shift into 5th on a transmission being monitored by a computer that only knows 4 gears, you will obviously not be limited ( by rev or speed ).

And if you have a built bottom end, i wouldnt be as concerned with the 5k rev limit, as much as i would be the fuel cutoff when you hit that, because on a turbocharged car, you don't want all air and no fuel in your combustion chamber. I think you're supposed to pull the tranmission sensor for every gear that you dont want a limit in,

Have fun

[Biggamehit]

i have no speed of rev limit just cut wire/pin 34 yellow/red and unpluged all transmission sensors minus reverse lights

however i never go beyond 6800 rpms with my stock vavletrain
Modified by Biggamehit at 10:27 AM 11/7/2006

[Dustin240]

I unpluged the 4th and 5th gear sensor today at school and no limiter (speed & RPM). And no check engine light.

[CleanSfourteen]

I unpluged the 4th and 5th gear sensor today at school and no limiter (speed & RPM). And no check engine light.

glad to hear it worked! enjoy

[Biggamehit]

welll just unplugging the sensors dont lift speed limit just rasies revs. honestly beyond 6900 in stock form is worthless i found out the hard way. we dont make anything up top with stock valvetrain and stock intake manifold setup, u have to cut wire in-order to bypass speed limit and u will still have speedo signal. i did the speedo switch thing a while back and all that does is make u think u are going faster, all it does is breaks the circuit using and SPST switch.

[CleanSfourteen]

For the speed sensor, you souuld be able to clip the wire that runs to the ecu...

This diagram is for a 97 240sx

[Biggamehit]

for obd1 dohc 240s it Yellow/red pin 34, o happy day when i clipped that wire and took it on the highway with my digital speedo that tops out at 399kmh (247.9 mph) i have not been anywhere near that yet cause i dont have that much power yet lol. i have been to about 130 befor i had to shut it down so it works. no fuel cut at all.