What would cause VTEC to spuraticly disengage or stop working?

Also, the speedo will sometimes jump around, make VTEC stop working and fall dead at zero km/h. This is only after the engine has been revved and put into VTEC (sometimes a sec after or many revs into VTEC for it just to jump in and out of VTEC).

I believe the it to be something in the wiring somewhere and not mechanical because of the fact that if the car is never drove into VTEC. Nothing with the VTEC or speedo ever acts up. Everything drives and works normal.

Please give me some insight on what this could be. I can provide more info if needed. Thanks.

 

Bump.

 

Factory honda ecus rely on a speed sensor to engage vtec.
If your speed sensor is malfunctioning on a stock ecu, your ecu will not activate vtec.

 

I'm aware of that but I don't believe the VSS has a problem. I believe it to be wiring of some kind or a ground maybe. What are somethings I can check?

 

Anyone?

 

mine is doing the same exact thing except i dont jump out of vtec.. it jumps to like 120mph when i accelerate..my mechanic said it had nothing to do with my vss..he said that the hardness behind the cluster is corroded.. im just trying to find that piece and see if thats the problem..any ideas with this would help me also...if u get yours fixed dont forget to tell me

 

well mine is doin the same problem to. today i change the vss sensor and v tec still does not kick in. I think my wiring is bad cause i found a wire that is not connected but i don't know where it goes. Does anybody have any ideas wat can be the problem. Cause i am tryin 2 get mine up and runnin for honda day and ****

 

Yea, that's what I'm thinking it's something like that... I don't know what to do other then buy harnesses and swap them out. But that's a pain in the *** and a waste of money if that's not it.

 

To tell you the truth I would try one thing. Pull off the plug for the VSS sensor. Look inside of it. Sometimes when you take off coolant lines of other things it will drop into the plug and corrode the plug side (not sensor side). Pull the pins, clean them off and away you go.

 

Thats the first thing I did. I blew in it. Some coolant flew up right in my eye and mouth. That wasn't fun. But yea, I did that. No change...

Thanks though. Next...

 

ive check at honda for them harness..you have to buy to whole thing and change the whole thing if your going to do that..plus tht thing is like 40-50 bucks

 

i had the same problem, it was the vss

 

i wish i could get it fixed

 

I'll try it. I don't have a VSS to try and they're problem not cheap. I'll see if I can borrow one or something and find out if that is the case.

 

Anything else it could be?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EKhothatch &raquo;</TD></TR><TR><TD CLASS="quote">I'll try it. I don't have a VSS to try and they're problem not cheap. I'll see if I can borrow one or something and find out if that is the case.</TD></TR></TABLE>
right on

 

bump

 

well,on my integra ls,it was doing the same thing as you guys too...first,it start off jumping around...everytime you floor the pedal @ 70mph,the speedo jumps up to 120 mph...after awhile it stop working,so i pull the speed sensor off of my gsr in my hatch and still not working...so id check the cluster & wiring that goes into the cluster & out to the tranny,still nothing...id tooked it to one my buddy that own a speed/salvage shop over here and they told me that it could be something in the tranny(forgot what its call) that spins the shaft on the speed sensor could be lock up or not functioning right???........

 

Bump. This still hasn't been fixed and the problem still hasn't been pin pointed. Please advise, what else can be checked or what it could be. Thanks.

 

Check your oil level. VTEC is dependant not only on your sensors but oil pressure. If oil is low there is not enough pressure to engage the Pins.

 

It has adequate oil and oil pressue. I am 100% sure it has to do with speedo/VSS.

 

I have found and fixed the problem...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rtype16 &raquo;</TD></TR><TR><TD CLASS="quote">To tell you the truth I would try one thing. Pull off the plug for the VSS sensor. Look inside of it. Sometimes when you take off coolant lines of other things it will drop into the plug and corrode the plug side (not sensor side). Pull the pins, clean them off and away you go.</TD></TR></TABLE>



He was right. When the swap was sitting, I remember there was some coolant sitting in the plug. It must of corroded the prongs on the VSS itself. I took the VSS off and cleaned the contacts as thoroughly as I could. Works like new again now!!!! Thanks!

 

You beat me to it
i just had same prob over the weekend, it had been speradic for awhile
finally died at ATCO in PW/S class FIRST ROUND OF eliminations no vtec that suckd

anway, i had to clean the terminals they were correded as hell

but its perfect now

good luck
d