I have a 99 GSR swap in my eg, well since i lost my license my dad drove the car and filled it up with 87 octane. today I got my apex ws2 exhaust put on with a 2.5 hi flo cat. just last week my vtec was engaging and i could hear it with my old exhaust, now i dont hear it at all, is it the gas? does it need 89+ octane? could it be i cant hear it with the new exhaust?? and my headgasket and the seal under the vtec solenoid(what is the seal called?) is leaking a little bit could that be it?

 

The seal under the vtec solenoid is the cam seal and no, it wouldn't keep vtec from engage. The leaky cam seal is a common problem with hondas.

 

how about the gas?

 

It it engaging and you don't hear it, or it's not engaging at all? And put some 93 in there, it will be happier.

 

Gas grade should not affect VTEC engagement but it can decrease power slightly (ie. down at the lower rpm where the KS is functional and can pull timing and only if you're running an ECU that looks for knock, OBDI PR3, P30, P72). The seal under the VTEC solenoid is actually NOT the cam seal, it's simply the VTEC solenoid gasket. Unless it's leaking a lot that shouldn't cause you any problems at all. You need to mechanically and/or electronically test the VTEC solenoid. Mechanically, with your motor at idle unplug your VTEC solenoid (single wire connector) and run a wire from your battery (+) to it, with the one end secure on the battery touch the other to the pin inside the VTEC sol. connector. If it bogs your motor down a few hundred rpm (this is audible too) everything is mechanically fine and it's most likely something with the ECU or wiring. If it doesn't then it's not entirely if not at all electronic, VTEC solenoids do go bad. Is your oil pan dented? Hows is oil pressure at the head? Has your cylinder heads VTEC rockers ever been removed? Electronically this is the safest way to do it but I'm sure you could figure out other ways... With your VTEC solenoid plugged back into your engine harness tap into this wire (a splice connector will work just fine), run this tapped in wire inside your car and connect it to your tester (if it's a test light connect on side and take the other side to ground) then go drive the car. If the light or voltmeter shows 12V+ when VTEC should be engaging the the ECU are okay. This should give you a start if you wanna do a few tests that just take some time... Sorry to ramble on soooo long, just got out of a boring class.

 

isn't it a bad idea to engage vtec at idle/low oil pressure?

just asking...

 

No, if you've got the pressure to lock the VTEC rockers at idle then the head is getting more than enough oil to lubricate and it's not like the rocker pistons takes oil away from that once it's pressurized. VTEC doesn't have anything to do with it, it would be a different story if you had low oil press at the head to begin with. Even if it were it's a 2 second test anyway...

 

thanks a lot