Update on post 14

I'm no noob to diagnosing Hondas or motors or anything but this issue has me stumped. The motor is a b20v gsr head whatever. Its been running in my car since April with 0 problems. The other night, i had it out for a drive and vtec just wouldn't work. I noticed it coming out of a hard turn, so i figured that my oil might have been low or something even though it worked fine earlier that night. Level was good. So here is the point im at. Ive tested/done the following:

-replaced solenoid screen and made sure plunger/pin in solenoid was free
-12v to solenoid, it clicks
-wire from solenoid into car ohm'd out
-removed oil supply line to head and blew out with air blower onto a shop towel. checked for debris, nothing.
-Hondata DOES switch to the high cam map

I have not touched this motor internally since October or so. So that eliminated forgeting an orifice or something of that nature.


So I've only got a few options at this point. Check overall oil pressure(doubt it), pull t fitting off back of block and check for blockage, check for 12v coming from ecu at vtec engagement, or drive it off a cliff.

Let me know if you could think of anything else that it might be.

 

As I was just saying in another thread,
Stock Vtec needs:

Oil pressure
Engine speed signal (RPM)
Vehicle speed signal (MPH)
TPS signal
MAP sensor signal
Coolant temp signal

Perhaps one of the signals isn't getting to the ECU. Checking the oil pressure would definately be the most important test since it's the only cause of the Vtec not working that can damage the motor. You can test wires in the engine bay and then at the ECU to check for breaks. You can also check the Vtec wire at the ECU while someone is driving to make sure it's not sending the Vtec enagement signal.

 

Love the loc btw. I'm from MD myself but I don't eat chipotle.

 

Sounds like you've covered the bases pretty well, I'd verify oil psi next.

 

It switches maps from low to high cam like it should, which would eliminate the vss map tps coolant temp sensors.

 

Then check the VTEC solenoid wire for activation when it's suppose to engage.

 

Still need to take a ride with a test light and see if +12v comes off the ecu when its supposed to. I hope so, I'm gonna be a mad guy if my ecu is fried. I really don't think its an oil pressure issue at this point. My girl has had my beater since this issue and my motor hasn't blown up yet lol.

 

Another option: Use one of the output features on Hondata to run vtec off a pin other than the stock one. That might work.

 

New solenoid, still no fix. Gonna take a ride with a test light today.

 

Post results with test light

 

Haven't done the test light yet, but at idle, I cracked the fitting loose at the back of the head and oil was spraying heavily. I'm pretty sure is has sufficient oil pressure and there is no blockage where its t'd at.

 

I read the post, and before I go into what I think it is, always remember the KISS theory
(Keep It Simple Stupid)

Question #1 Check engine light? im guessing no
Question #2 Tuned or stock ECU? I hope its not stock

if no check engine light I would make sure the check engine light is not burned out, all honds that I know of that have Vtec will trigger check engine if it does not kick in,( I could be wrong, but I had a problem with vetch oil pressure, and changed vtec solenoid with a new one, and rewired vtec, turned out to just be a bad ECU(ECU works vtec does't) but you should get a check engine light.

 

Check engine light works and is not on. The VTEC solenoid is detected by the ecu, so thats why there is no code. It is not a stock ecu, I have S300.

The car does have 13.3-13.4 volts from ecu when vtec kicks/was supposed to. So that eliminates ecu. I just bought a pressure tester so im going to do that tomorrow. Also, i took a wire right off the battery to the solenoid while reving the engine to 5k or so as per the repair manual. No vtec so now im almost positive the oil pressure has to be low.

 

Alright did a few more things today.

- Removed factory pressure sensor and hooked up gauge. reads about 25-30 psi at idle. Sounds about right considering i have pro1's and a small vac leak i found today. I know that could be the issue in some cases, but hondata still switches maps so i dont think so.

- Hooked up gauge to port right in front of the vtec solenoid. The manual says it should read below 7psi at idle. Mine reads 0 at idle. It then says to rev the car to 5k and jump a wire between the battery terminal and the solenoid. The gause should read 57psi IIRC mine still reads 0.

- Removed solenoid and bench tested it. Checked out good.

- While solenoid was off, I removed the oil supply fitting in the back of the head and fed a zip tie through to make sure there were no blockages. Nothing.

- Hooked it all back up and bypassed the vtec wire in the wiring harness. Even though this wire ohmed out I still ran a test lead to the solenoid. Still nothing.

Im stumped. Even if there were not enough pressure/a blockage, shouldn't that port next to the solenoid get some sort of reading when the solenoid is forced to open?

 

heeellllpppppp meeeee

 

throw some ideas out. im stumped

 

Damn, someone take a guess!

 

Despite your bench testing of the solenoid and running a seperate wire to it to try manually activating it, unless you've tried another known good solenoid, I'll put my money there. It might open when there's no pressure hitting it, but maybe it's worn out enough that when 50psi+ is, it still stays shut.

 

I did that too.

 

Did you recently have head work done? Possibly one of the rocker pins is missing?

 

I have stated that the motor has not been touched internally since October. Bump.

 

what about an oil control orifice?

 

Im thinking maybe one of the ones on the cam journals might have blown an o-ring.