Rep Power: 285

anyone had problems with their vtec coming on late? Mine is coming on at about 5300-5500 rpm.

This is also causing my secondary runners to open late, causing a loss in power also. So this is causing a hell of a power loss at 4500-5500 rpm.

The only mod i have done to the electrical system was tapping the vtec signal wire to open the secondary runners on my intake manifold. And its only been having this problem the past several days.

My only CEL is for a missing secondary O2 sensor.

This is beginning to bug me. Anyone have a similar problem? (minus the GSR intake manifold)

 
Rep Power: 812

hmm well i thought we proved vtec will only come on when at full throttle, car is at operating temp, and oil psi is hi enough. so one of those is causing a problem, or you have clogged oil passages/bad vtec solenoid. With all conditions met, vtec should engage at 4500rpms roughly. one thing that worries me is that tapping of the vtec wire. does that alter the voltage that the ecu sees in any way?

 
Rep Power: 285

it should not alter the voltage, only the amperage. But the solenoids take soo little amperage that it should not have hurt anything.

It was working properly before.

I fixed my full throttle problem (throttle plate would actually open about 100* instead of only 90*.

And my coolant temp seems to be ok according to the dummy guage. I dont have a live-feed OBD2 scanner of my own. So i will have to acquire one from somewhere in order to check that out.

 
Rep Power: 0

I'm just curious, which wire is the vtec signal wire? Is the vtec solenoid the same thing? Because I plan to ground that point. Thanks!

 
Rep Power: 812

there are vtec input and output wires I believe, and then there's the vtm wire. can someone confirm this?

 
Rep Power: 285

there is a vtec signal wire that goes to the vtec solenoid to engage the lifters to use the vtec lobe.

There is only 1 wire on the vtec solenoid. It grounds itself through the block.