While racing at Buttonwillow this past weekend, during the final ITA race on Sunday, I dropped my best lap time ever around the 5th lap of a 13 lap race. 2:15.8 on #25A CCW on new RA1's; started the weekend putting down 2:20's on really old, pretty used up RA1's. I elatedly dove into my next lap when I noticed the check engine light came on. All gauges looked good (oil pr, vlts, temp, etc.) and the engine sounded normal, and seemed to be running just fine, so I figured I'd continue until something did sound or look awry. Next time around, after hitting all my lines, braking points, and apexes (sp?), and expecting another stellar lap, my time read somewhere in the 2:17's, a lap later, in the 2:19's, and I couldn't seem to break 2:19 after that for the rest of the race, doing some of the best driving I've ever done. Obviously, I was down on horsepower.

After getting back to the pits, I check the CEL code, it gave me a 22, which is the VTEC Oil Pressure Switch. I went to the model specific forum (92-2000 Civics) looking for info on the pressure switch and what the most likely problem might be for these particular engines (stock D16z6), whether the sensor/switch actually goes bad, or wiring issues, and such. For it being a model specific forum, there were pretty much only posts regarding JDM engine swaps and "I've got a 93 civ Hatch with a type R integ motor in it, throwin' a 22 CEL, What up, yo?".

I know how to figure out if the switch itself has gone bad, whether it's a wiring issue back to the ECU, where to get a replacement, blah, blah, blah. What I want to know, and what I couldn't find out in any of the other forums, is do I really need the pressure switch for a track only car, or can I bypass the switch entirely, and what are the ramifications of said actions? I thought I read somewhere that VTEC will only kick in at a certain oil pressure, with the VSS showing a reading of at least 5mph. I may be wrong, but if this is true, would it mean the VTEC will kick in at exactly 5mph with the switch bypassed?

TIA

 

From what I've read, the car must be moving (hence the 5mph), there must be enough oil pressure, and the engine has to be at full throttle. I'm not sure about the car being at full throttle though, from experience I've had vtec crossover coasting ~90mph in 5th (puts the engine at the rpm for the vtec crossover). Someone correct me if I'm wrong, but being on the big lobe at lower rpms creates less power because the air velocity going into the CC is lower. But then this wouldnt matter too much as a track only car's engine dwells in the high rpms. Hopefully you can take something out of that.

 

the pressure switch is just a saftey device. it reads oil pressure.im sure if the code comes up the ecu will downgrade performance to prevent damgage to the motor from running it hard with low oil pressure.
with that said you dont need it.jdm engines dont have them at all. you can just loop the wire at the ecu to bypass it.

 

pfft, I just put a damn bolt in where the pressure switch was cause the damn head I got didn't have one. 8)

 

in a way I think it's nice to have enabled, you just found out that you have oil starvation... which will cause a lot worse problems than a crappy CEL.

 

That is, if it's not the switch failure itself. I'm really hoping for a busted switch over oil starvation. After flogging the car around that track for 2.5 days, without really any problems, for that to crop up at the very end of the whole weekend lends me to believe it's the switch. I'm starting to get to that point where switches and sensors are starting to fail. I've already had to replace the TPS and VSS in the last 4 months, so I really won't be suprised if another one has gone bad, but I'll have to check it out to be sure, which is fairly simple to figure out. I have an Autometer oil pressure gauge hooked up at the port where the car's OP idiot light sensor is, and I never lost any oil pressure, so I'll assume if there was enough pressure there, there was enough up at the top of the head. Of course, I'll assume that until someone tells me I'm wrong. ha ha.

 

Just to throw another view out there. I kept getting the CEL 22 with my old motor on VIR south course. Couldn't figure it out, installed an oil pressure gauge and saw oil pressure was dropping by 40psi when vtec engaged. Turned out the company that did my headwork didn't reinstall all of the pins/pistons in the rocker arms.

Moral of the story is that the cel 22 can point out legitimate problems. However IIRC, some jdm motors don't have this switch and also a real oil pressure gauge can help uncover problems as well.

 

there is a test you can do to check the switch. all you need is an ohms meter. ill post the info when i get home. you may need to clean the oil screen that is in the vtec housing and i would not recommend driving/ racing the car with out the switch in place.