I have a 94 civic ex with a b16a2 in it. Everything is working great, no cel, no hesitaion... I have a problem tho, my vtec wont enguage untill 5800... I have a chipped p28 from "ag engenering" and it works fine but no matter what chip I use it always kicks in a 5800....

Any ideas??? Oil pressure sensor maybe, vtec solinoide, or oil leak?

 

You might not be able to modify the VTEC engagement point without using some sort of programmable ECU, or Piggy Back engine management system. Some of these systems (I think AEM makes one) should allow you to change the VTEC switchover. But doing this might have adverse effects.

The VTEC cams profile is alot more aggressive therefore if you engage VTEC sooner your intake vale will open sooner and allow more air into an engine that may not have enough fuel to match the perfect fuel air mixture that gives you the most power per explosion, with the greatest reliability. (i.e. You will be running lean).

Running lean usually gets you a bit more power at the expense of ALOT more heat. More heat = less effieciency = less power. So overall, running lean isn't good.

To fix this, increase the amount of fuel you put into the engine at the same time and you should balance out.

I'm no rocket scientist, but the theory is sound. You might want a second opinion though.

Jay
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