ever since my speedo went my car wont crack vtec is that why?

 

Speed is an important input to your engine computer it helps determine load on the engine.
So without all the proper inputs v-tec won't work.
I am guessing your check engine light is on.

If your lucky the speed sensor has just become unplugged or you may see what has failed.

 

Yes, Vtec won't work below 5 mph or something, so your VSS shows as if it is 0 mph and Vtec won't work.

 

its actually 20mph. no speedo = no vtec..... just be glad ur car doesn't do what mine does

As long as I don't let the engine decelerate(engine brake) it won't throw a VSS code. And VTEC works just fine. As soon as I let engine decel in a gear for 2k Rpms (i.e.- 4500-2500) the CEL comes on and VTEC goes away, but I can still rev to 7900rpms.
Oh.....And i can just turn the car off and restart it and I have VTEC again

 

Just send a little bit of voltage to your VSS wire constantly, and it should work fine....ghetto cheap fix.

 

Mine does the exact same thing. I have an extra VSS, just been to busy lately
to fix it

 

Im thinking it might be the whole assembly on my part. I replaced just the electrical sensor on the top of the unit, and it worked fine for a week, then started this whole fiasco.

When i first did the motor swap a few years ago, my speed sensor unit was never bolted back to the trans. The speedo would shoot up to like 80 when i was doin no more than 10mph, and then it would just bounce around, and then quit working, and then bounce around.
and I'm thinking the gear on the end may be causing an issue. I haven't even taken it out, so i can't be sure about it either