I have a 97 GSR engine. The head just got a valve job plus new: valves, springs and retainers. The MIL only shows code 41 (i only have 1 02 sensor.) I ran a test light to the VTEC solenoid and it turns on at 4400 rpm like it should. This makes me think the problem is mechanical. Maybe the machine shop did something wrong.? Any ideas? Thanks

 

check the solenoid screen.
Check your oil level.

 

I've been through all the simple stuff already. I also swapped the solenoid and pressure switch with another set from a working 99 Si engine.

 

Did you try swaping out the ECU? If you cleaned the screen and swaped out the Sileniodand still a problem,Then Lok at the wiring(Pinched cut crimped)wires, there are only three wires for the V-Tec wiring,1 for the selinoid and 2 for the oil/VTM switch.
Good Luck!

 

Thanks for the advice, but I really dont think the problem is electronic at all. I've done about 30 swaps in Hondas before and never had a VTEC problem that couldn't be fixed. I actually used my engine harness and ecu in a different car with a different engine and everything worked fine. As far as I know, if any sensors or solenoids (or wiring to them) aren't working- I would have a check engine light to show that. The VTEC solenoid IS getting power at 4400 RPM.
I suppose i should find an exploded view of the head, so I can tear it apart myself and look for the problem.

 

Check the oil pressure reading from the port at the front of the head by the solenoid. It's a M10x1.0 adapter that you'll need.

If the oil pressure checks out, I'd check the rocker arms and sliding pins.

What makes you think that VTEC isn't turning on despite the positive voltage on the VTEC signal wire?

 

Ok...this might seem stupid, but you said you basically put on the head... did you make sure your oil control orifice was still in place ? (no orifice, no vtec)

You should also check your oil level and the pan to ensure it's not dented.

X2

 

thanks for the reply. I'll check the head for oil pressure before i rip it apart.
I know vtec isn't working because there is no change in exhaust tone at 4400 and it lacs high rev horsepower. The car has 3" exhaust, so I should deffinately hear it. (and the cams are stock)

 

You probably won't hear it. Stock GS-R cams and even properly tuned ITR cams won't transition that hard.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IN VTEC &raquo;</TD></TR><TR><TD CLASS="quote">You probably won't hear it. Stock GS-R cams and even properly tuned ITR cams won't transition that hard.</TD></TR></TABLE>

Where in the world do you guys get this from ? I have never been in a GSR that you can't hear or feel the vtec crossover by 5500+.... initially, it might be weak...but to not hear it...

X2

 

Look for that shitty little dowell pin under the #3 cam cap, I am aware that(or lack thereof) can inhibit your VTEC from activating...

It`s always the small stuff

 

Do you have cam gears? If I set mine cams on the retard to much the engine redlines at 7k instead of 9k. IT might be mechanical.

 

I don't know who told you what, but 5500rpm is when the 2ndary runners open.

 

solution: after checking oil pressure and finding it to be way to low (like 0-30lbs) I pulled the valve cover off and ran the starter. Oil was gushing from under the intake cam by the distributer. It turns out, the machine shop forgot to thread a plug back into a hole. It was letting so much oil push through, that I suppose there wasnt enough left to activate VTEC.

 

I'm just going to do some of the basic steps in checking to see why the **** vtec isn't working .
1) Oil level, its gotta be FULL. I'm talking at the upper mark on the dipstick.
2) Solenoid, Ok this is a 2 parter. A) take a wire (any wire) disconnect the grey plug on the vtec solenoid and touch the wire to the pos. battery terminal and the solenoid side of the grey 1 pin connector. there should be an audible click from the solenoid. B) If A checks out, remove the solenoid and clean the filter screen. (self explanatory)

3) Speed, the car must be going over 10 mph so the spedo must be working. that means the VSS has to be working. vtec is temperamental isn't it?

4) more oil, check the oil pan. if its dented POUND IT OUT!. this is why mine wasn't working. the pan was dented in far enough to hit the oil pickup for the pump to cause low pressure situation in the head, no pressure no vtec.

5) ECU Swap out to another ECU that you KNOW vtec works on.

6) Car must be at I belive its 80 degrees or higher so let car get to a normal operating temprature.

7) If none of the above work, you might want to pull the solenoid off the head, remove the solenoid filter and verify the piston moves freely.

Thats a basic troubleshoot for it. if i missed anything or got anything wrong just reply and ill change the info.
If you go through all this and it still doesn't work its oil pressure (the pump) or wiring related. so check all the wires for vtec.
Thats it i hope it helps some people.

from my troubleshoot i wrote a year ago

 

great post thanks for the help.

what is does the oil presure have to be at for vtec to cross over?

i rebuilt my motor about 5 months ago and when it warms up the oil presure drops to about 45-50 psi @3k at operateing temp. is this not enough presure to activate vtec. what are the causes for that drop in oil presure at operateing temp? The motor was blown before..(spun rod bearing) could the oil pump have went bad? i replaced the gaskets in the oil pump. i really dont feel safe running it like that.

according to my guage im getting next to no oil pressure at idle. should i invest in a new oil pump?

I find it too much of a coincidance that something caused the motor to blow up in the first place and now have low oil pressure.

thanks larry

 

Why did it not trigger a Vtec Oil Pressure CEL??

JDM engine?

-PHiZ

 

i was wondering the same thing im not getting any cel's
im running a p28

 

did u look at the vtec oil pressure switch?

 

ran some tests today and the solenoid clicks over when i send it power (so i know it works) and i know that the solenoid is getting power at 4800 rpm so i guess its working. you cant hear it at all though i checked and cleaned the screen and its ok i even had a friend rev it up to like 5 then i hard wired the power to the solenoid and you still dont hear a thing. is this normal? whats my next step?

try an oil pump and see if thats where im looseing oil pressure?


get back..

larry

 

have you checked your oil level?

 

um no im a moron

yeah i checked it you douchbag