speed restriction prob

[Jersey]

i bought a 1990 240sx and swaped running single cam into it ans put a 5 speed into it and the car now runs but when i get into 3 4 or 5 gears it hits a speed restriction around 4 rpm if im in it but i can normal crusie and it be fine bu its hard to do highway speeds. i know i dont need to speed i dont like to but it stupid thag it dose that. anyone got anything on this.

the transmission ia out of a 97 240sx but would that affrcy anything my buddy didnt hook anything on the trany cause no plugs matched up since the 97 transmission is more modern then the car itself. also my cluster is messed up the mph dont work but i have a replacment for that but its not sitting on zero it jumps all over the place could that be another reason for the speed restrction?

[compactfean]

yeah that could be the problem. the computer needs a steady mph signal. your gauge gets the same signal so definitely. also the 5th gear sensor can play a role in that as well. ....use the s13 speed sensor.

[zachattack_5491]

It could be from jumping around. Just unplug it until you get the correct sensor.