Thread: Intermittent RPM signal above 7000 rpm

Hey guys,

I have a vtec controller to activate cams which gets its RPM signal from pin #2 on my b13 ECU pinout. The issue is that I'm getting intermittent rpm signal above 7000rpm which deactivates/activates cams on the way, my question is can I get rpm signal from another pin, say #3 for example? The other option is to just wire the rpm signal cable to negative on the distributor coil.

Any thoughts?

Are all the wires connected properly and firmly to the controller?

I had a problem with my MSD window switch coming loose now and then again and shutting off VVL, then I tightened up the wires, not a problem since

Like was stated, connections are likely loose somewhere. You can take the rpm signal off the dizzy but I have heard that there tends to be inconsistency with the signal there. Mine is wired into a sub-harness I made for my step-down harness. Before that it was wired off the back of the ECU.

You can also wire it into the back of the cluster like so:

http://www.sr20-forum.com/vvl/66418-don-t-want-splice-your-wiring-tap-your-rpm-signal-here.html

Idea taken from here:

http://www.g20.net/forum/showthread.php?101829-HowTo-Wire-RPM-Switches-for-VVL

Here's how I figured out the connections were loose:

the VVL would only deactivate on certain roads that were on an incline (going up hill). meaning, gravity pulled the MSD box (which is located on the passenger floor under the dash) away just enough to disrupt the connections. I remember it happened on the exact same road every single time I went to WOT. a few zipties and making sure it had more slack solved that.

The weird thing is it only does it when over 7.000 rpm and almost like a consistent on, off, on, off, on, off don't know if I'm explaining myself..

I'll double check my connections just to be sure.

Thanks for the input guys, I'm using nemu RT BTW

It could be because at 7,000rpm+ it means your moving faster and thus its moving back more (more intertia)

You can wire it to the back of the instrument cluster.

Ditch the switch and use nemu to activate it...

Thats the easiest way to do it. But not the cheapest.

Changed the switch RPM signal cable from pin #2 to pin #3 and problem fixed!!