VTec problems not kicking in... PLease help
 

Hey,
I have a few problems with Vtec kicking in, when I had the car on the dyno it was working ( so we think) but it stopped working, we checked to make sure its getting power from Ecu and it is.
On the s300 it is switching maps like Vtec is kicking in, but it isn’t. I have changed the following,
Vtec Solenoid added a LS/Vtec line thinking the head isn’t getting oil pressure.

I added a oil pressure sending unit on the front of the head to check oil pressure and it never went over 25psi,when a head takes 50 psi. But wheat don’t make sense is I added the ls/vtec line to feed oil straight too the head.

What else would you guys suggest I try?

Re: VTec problems not kicking in... PLease help (B18c1turboedEK)
 

Where is your ol supply for the head coming from? Back track the lines and passages for a blocked or semi-block port.

Dumb question, is the oil filled and does the oil pan have dents?

Re: VTec problems not kicking in... PLease help (B18c1turboedEK)
 

Pressure switch verifies vtec activation to the ecu. Vtec only activates when you have speed at the wheels and your at/approaching operating temp, so be sure your not doing some type of testing just revving the motor.

If you verify the pressure switch is closing, then vtec is working.

No check engine lights during all this?

You think it was working on the dyno, yet your sure it's not working now?

Re: VTec problems not kicking in... PLease help (Turbogixxer)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbogixxer &raquo;</TD></TR><TR><TD CLASS="quote">Where is your ol supply for the head coming from? Back track the lines and passages for a blocked or semi-block port.

Dumb question, is the oil filled and does the oil pan have dents?</TD></TR></TABLE>

Ok the line i added is coming from the golden eagle oil adapter. i just added the line yesterday so i dont think its clogged.
yes their is oil in the motor, i cant tell of any dents in the pan,due to i have the moroso oil pan and its flat under it, it dont looked dented at all....

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RC000E &raquo;</TD></TR><TR><TD CLASS="quote">Pressure switch verifies vtec activation to the ecu. Vtec only activates when you have speed at the wheels and your at/approaching operating temp, so be sure your not doing some type of testing just revving the motor.

If you verify the pressure switch is closing, then vtec is working.

No check engine lights during all this?

You think it was working on the dyno, yet your sure it's not working now? </TD></TR></TABLE>


Nope no check engine lights, we pulled the car of the dyno becasue it wasnt working.I have test driven the car on the street after changing all that stuff and it sounds the same.

I am road testing the car after warm up and speed also, vtec is set too kick on at 4401 and it isnt. i am road testing the car not just reving motor up

Re: VTec problems not kicking in... PLease help (B18c1turboedEK)
 

Dude, just backtrack the system. Start at the pressure switch like I said. The switch just closes and sends a ground signal to the ecu to confirm the solenoid opened.

If your getting no cel, then it seems likely the solenoid is opening and the switch is closing. I'd still verify this. Just do a basic continuity in car between body ground and the pin at the ecu for the pressure switch. If solenoid opens, you should immediately get continuity.

If that's functioning, it's verifying the solenoid is opening and the oil pressure is high enough to activate the switch.

If adequate pressure exists then there has to be some issue beyond the switch. This is something I'd solve in person, but over the forum it's gonna be tough.

You said you placed a pressure gauge at the front plug on the head. The pressure at that location changes upon vtec solenoid opening...did you see this happen? Typical pressure out of vtec is low...but present.

Re: VTec problems not kicking in... PLease help (RC000E)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RC000E &raquo;</TD></TR><TR><TD CLASS="quote">Dude, just backtrack the system. Start at the pressure switch like I said. The switch just closes and sends a ground signal to the ecu to confirm the solenoid opened.

If your getting no cel, then it seems likely the solenoid is opening and the switch is closing. I'd still verify this. Just do a basic continuity in car between body ground and the pin at the ecu for the pressure switch. If solenoid opens, you should immediately get continuity.

If that's functioning, it's verifying the solenoid is opening and the oil pressure is high enough to activate the switch.

If adequate pressure exists then there has to be some issue beyond the switch. This is something I'd solve in person, but over the forum it's gonna be tough.

You said you placed a pressure gauge at the front plug on the head. The pressure at that location changes upon vtec solenoid opening...did you see this happen? Typical pressure out of vtec is low...but present.</TD></TR></TABLE>

Ok ill test the presure switch out. I changed the vtec solenoid out but used the same oil switch due to the other on being broken.
Wehn i added the oil pressure sending unit on the front i saw about 20 psi on the gauge and it never changed. when i got on the car and hit vtec range oil pressure stayed the same.

Thanks for your help man

Re: VTec problems not kicking in... PLease help (B18c1turboedEK)
 

Hey, let us know your findings.