Vtec Swap!!!

[You_Wish]

Ok So Im Really Confused On This Any info would be awesome..

Ok so i did a GSR swap on my ls integra wired everything through the harness to make it look as clean as possible and wired it to a p28 thats tuned for a b18c5 took it for a test run and no vtec. so i was like maybe it needs to keep reving past 4800 when vtec is suppose to crack. drove it like that for two days nothing changed. so we straight wired it to the ecu to make sure it was not wiring problems. still nothing so we pulled the vtec solenoid off and checked both screens and and they where clean. changed the oil pressure sensor as well and still nothing.. so we wired it to a switch and vtec cracks... im at a loss we have almost tried everything.. oh and i tried my chipped p28 in a friends car and vtec worked.

[Theycall_Metue]

could be bad connector pin at the ecu

[wrekonize]

low oil....
no knock sensor...
off timing.....
wrong valve clearance
i had a friend same problem could not figure it out...and it was the oil filter..so do a oil change and filter change

[big mac]

yeah but p28 dont need knock sensor for vtec to egage

[Tech5]

make sure the vtec solenoid wire isn't pulled out of the connect , matter fact push in all the wires on every sensor for vtec

[You_Wish]

^^ Thanks For All The Info I Have Done All That

[all_motor_ek]

i just did a gsr swap in my ls. im running a p72 ecu chipped with chrome. with knock sensor deleted.
i wired my vtec and everything straight to the ecu drove it and it didnt engage either.
took the solenoid off it was still clean.
i had oil in.
finally my homeboy told me maybe im not getting enough oil pressure for it to engage so i changed my oil from 5w30 to 10w30
and vtec kicked eversince

[You_Wish]

^^ Im Gunna Try That Thanks Man

[Vteckidd]

make sure your oil pressure is high enough. Lots of swaps have dented oil pans that starve the motor for oil pressure which keeps VTEC from working. If you can make it engage with a switch, that means you wiring isnt the issue.

You need to determine if it is a MECHANICAL issue or an ELECTRICAL.

1) How to check if it is electrical:
-Take solenoid off, with 12 volts it should "click" or engage that will verify the solenoid works
-At idle, jump the solenoid with 12 volts, if it "engages" the car should bog and die down and almost shut off. Basically by hotwiring the solenoid you are "engaging" vtec at idle, which will make the car run like shit. If it runs normal and doesnt die, then the solenoid isnt working or there is a wiring issue.

2) How to check if it is mechanical:
-VTEC needs IIRC 55psi of oil pressure to properly engage. It also has to have speedo signal( keeps VTEC from engaging at idle and low MPH), and coolant temp (Keeps vtec from engaging when the motor is cold).
-Hook an oil pressure gauge up to the bottom of the block, usually where the factory oil pressure sending unit is. Oil pressure should be pretty high. If it isnt, you have an pressure problem in the bottom end somewhere. Bad oil pump, clogged pickup, dented or damamged oil pan etc
-If pressure checks out good, hook an oil pressure gauge to the port on the front of the head by the VTEC solenoid. This tests pressure BEFORE the solenoid. Pressure should be 55psi=90PSI in vtec. It needs a minimum of 55 IIRC to engage. So if oil pressure is low there, then there is something between the block, and the head that is keepiong pressure down.

CHECK THE OIL PAN FOR DENTS

[You_Wish]

make sure your oil pressure is high enough. Lots of swaps have dented oil pans that starve the motor for oil pressure which keeps VTEC from working. If you can make it engage with a switch, that means you wiring isnt the issue.

You need to determine if it is a MECHANICAL issue or an ELECTRICAL.

1) How to check if it is electrical:
-Take solenoid off, with 12 volts it should "click" or engage that will verify the solenoid works
-At idle, jump the solenoid with 12 volts, if it "engages" the car should bog and die down and almost shut off. Basically by hotwiring the solenoid you are "engaging" vtec at idle, which will make the car run like shit. If it runs normal and doesnt die, then the solenoid isnt working or there is a wiring issue.

2) How to check if it is mechanical:
-VTEC needs IIRC 55psi of oil pressure to properly engage. It also has to have speedo signal( keeps VTEC from engaging at idle and low MPH), and coolant temp (Keeps vtec from engaging when the motor is cold).
-Hook an oil pressure gauge up to the bottom of the block, usually where the factory oil pressure sending unit is. Oil pressure should be pretty high. If it isnt, you have an pressure problem in the bottom end somewhere. Bad oil pump, clogged pickup, dented or damamged oil pan etc
-If pressure checks out good, hook an oil pressure gauge to the port on the front of the head by the VTEC solenoid. This tests pressure BEFORE the solenoid. Pressure should be 55psi=90PSI in vtec. It needs a minimum of 55 IIRC to engage. So if oil pressure is low there, then there is something between the block, and the head that is keepiong pressure down.

CHECK THE OIL PAN FOR DENTS

there is very little dents in the pan. and is does idle like shit when i have the switch turned on and when we stright wired it up..

[Vteckidd]

there is very little dents in the pan. and is does idle like shit when i have the switch turned on and when we stright wired it up..

then you know your solenoid works as long as it is getting power. You can hook a test light up to it and free rev it, or drive it under load to see if at the required RPM and speed the solenoid powers on.

Sounds like a mechanical issue. Even a slight dent can affect the oil pressure enough that it wont operate properly

[You_Wish]

Could it be because my vtec sileniod is leaking

[*EFilliated*]

As far as I kno on stock ecus vtec only engages in Full throttle. If its chipped then it shouldn't matter, I have also seen dizzys causing vtec to break up and not engage

[Vteckidd]

Could it be because my vtec sileniod is leaking

not normally know. Unless it is spraying oil out, a small leak will not effect vtec, but i would fix it anyway

[You_Wish]

As far as I kno on stock ecus vtec only engages in Full throttle. If its chipped then it shouldn't matter, I have also seen dizzys causing vtec to break up and not engage

Dizzy is brand new

[You_Wish]

not normally know. Unless it is spraying oil out, a small leak will not effect vtec, but i would fix it anyway

It's poring out lol I'm fixing it

[Vteckidd]

then that could cause a drop in pressure enough for it not to engage. Fix it report back

[YoItsCarlie]

Have any CEl codes?

[You_Wish]

then that could cause a drop in pressure enough for it not to engage. Fix it report back

Well i changed the gaskets and oil pressure is a lot better gunna re wire it up tonight and ill let you know

[allmotor-teg]

i would say, try to make sure everything is sealed, change the oil, filter, any cel's on??

[You_Wish]

No cel

[allmotor-teg]

No cel

weird, so when vtec is suppoused to kick in lets say 4.800rpm it doesnt but still revs higher just no vtec or it doest pass a certain rpm??
did someone with alot of exp did the wirering??