Jumping Tach

[Morph]

Hey guys i got a question i've noticed lately that when im accelerating and giving it constant gas the tach needle jumps from 2500 to 3000 and back. I searched google, and on the vr6 forum they said that it was an ignition coil is this true for the 240?

[Hijacker]

i take it this is with a 240 with an SR? you need to give us some more info. What year 240, what gen SR. There are quite a few variables that can come in handy knowing.

[Ralph]

Hmmm...I'd like to know some info as well. I have a 91 Redtop SR in my S14 and I get that same "jump" at the same rpm every now and then. Doesnt appear to have any effect on performance, just randomly jumps here and there at the gauge. I thought it was my maf going bad for the 2 or 3rd time(used SOHC mafs, not wiring or any other malfunction) but havent really felt it was nessacary to look into further as of now.

[Morph]

I have a 91 coupe Black Top S13 Stock everything.

[Hijacker]

check your tach wire at the ecu plug where it goes up to the dash. I'm wondering if the connection isn't good.

[NY S13 SR]

Could be a coil pack, we have seen that happen before. Can you rev to redline without breaking up?

[nismostate]

i have a similar problem but it's on the speedometer. i'll be going 30-50mph and it'll drop to 0 mph. im sure mine is just bad wiring. also, my trip sometimes doesn't move. is that caused by bad wiring also?

[electricproblem]

yeah just check the wiring......my aftermarket tach did the same thing and it was just a loose connection

[Morph]

Yea runs great dies every so often but thats just the Bov.