89 civic hatch with LS/vtec swap-
Finished and tuned the vtec swap a year and two months ago...worked great then. I only had it going for about two weeks and put the car in the paint shop for a year.

Now vtec will kick in for the first gear it is reached in and possibly the second gear above 5k(as set by the tuner). Then about a second into that second gear it throws a code and vtec is gone until the car is shut off and turned on. Sometimes vtec shuts off in the first gear it is reached. ECU doesn't seem to be keeping the code so I can't check it.

My oil is full and I just did an engine flush and oil change. The vtec solenoid was brand new with the swap, but I still changed the gasket/filter. I've unhooked the battery to reset the ECU and that has changed nothing. I can only assume that the wiring is fine as vtec has worked all the way through a gear and it hasn't been touched since it worked fine over a year ago.

Short of tracing all the wiring I don't know what else to do. I've never shown something sooo much love and gotten nothing but misery back, not even my girlfriend.

 

hows the oil pressure? the vtec need alot of oil pressure to turn it on. so everytime you hit vtec and your pressure is low and it is unable to turn on. i dont really know wats the oil pressure for a Ls vtec so sorry but hope this helps find wats the problem.

 

i have the same problem but on my gsr.

 

Hmm haven't checked the pressure yet. Anybody know the best way to check it for the vtec only, or at all for that matter?
I don't think removing an oil plug and trying to hold my finger over it would be the answer

 

Oil volume and flow are going to be the first things to check. After that, check the wiring to the VTEC solenoid

 

whats your code?

 

Schister66-
Yea I will check this as soon as I know how to.

ARdb8-
As I stated the ECU is not holding the code, it seems it is only coding when the vtec cuts off and then it is gone.

 

So the CEL stays on until the car is shut off correct? Try pulling the code while the car is running and see what you get.. sounds like the vtec oil pressure sensor..

 

well im not so good at checking the oil pressure lol but it looks like its has to do with the oil pressure or the oil pressure sensor check those two out and see wat happens