I think I have a stuck thermostat. (I'm going to replace it today after work)
It must be stuck open because the car seems to not even get into normal operating temp on the gauges (I know the temp gauge works because it does move a little here and there if I'm in traffic or what not).

So would a stuck open thermostat cause the car to run too cold, therefore not getting hot enough to let vtec engage?

Thanks.

 

If the thermostat was open all the time, it would just take longer for the coolant to get up to temp. Maybe its youe temp sensor?

 

The problem is that the car will get warmed up and vtec will work fine.
If I drive it hard and I'm in vtec for a while (or just up in the rpm's for that matter)
vtec will cut out almost like its studdering and the harder I drive it the more and more it will cut out until finally vtec stops working completely.

Could the oil be getting hot enough from driving hard that the oil pressure actually drops, therefore causing the pressure switch to not allow vtec to work?

Does the weight of the oil have an affect on this. (I think I'm only running 30 weight right now)?
Thanks

 

Yes.

 

Id have to say that there is something wrong with your oil preasure because obviously if you are accually able to get into VTEC once the car is "warmed up" as you put it (key word being "warm") then it seems like there must be a problem in maintaining oil preasure...all i can say is that i would be careful and not be hitting VTEC until you know what the problem is

 

I have to agree with the cold engine theory. A stuck open thermostat and a fast moving car makes cold water. I wouldnt hurt to verify the sensors but, the gauge and the computer both have they're own so its probably not that. And, of course it wouldnt hurt to verfiy proper oil level either.

 

Well, here's an update....
Installed a vafc yesterday.
vtec still "cuts out" - So the only thing left to be the problem could be the vtec soleniod itself, right?
My theory being that the vafc doesn't "care" about temp, or oil pressure, or speed.
So the only thing left to cause this problem would be the soleniod.
I put a wire from the positive terminal to make sure that it clicks and works, and it does. But, is it possible for the soleniod to actually wear out. If the soleniod works upon magnetism, then is it possible to wear out and lose its "hold"

What do you think?
Thanks