I have a b18c5 in a 92 civic vx, stage 3 hondata ecu. No matter what I set the vtec switch over point to it won't come on until after 7000rpm. I've gone through all the troubleshooting steps in the helms manual. The oil pressure is fine, I'm not throwing a single code, I've even swaped the vtec pressure switch with a known good one. I've reset the ecu at least a dozen times.

One thing... I don't know if this would affect it or not. I still have the stock civic radiator and there is no thermostat in the engine. Could that be causing it??

Does anyone have any suggestions!

Any help is appreciated!

Thanks...

-=edit=- spelling mistake


[Modified by neumonik, 8:56 PM 4/3/2002]

 

The problem will have nothing to do with your radiator or thermostat. just out of curiosity...is the Hondata calibrated correctly? This reminds me of something I learned on my ex's car(del sol S). She had a shift light with a 3,000 rpm pill in it but the light itself had a switch on the back that you would set according to the amount of cylinders. I noticed that if i would set the switch to 6 cylinder then her shift light wouldnt light up until like 5500. Either that or there is a defect in the Hondata unit itself....as long as you have the proper oil pressure then the VTEC should be crossing over fine. try swapping out the VTEC solinoid itself....one other thing, between the VTEC solinoid and the head is a "funny looking" o-ring with a screen , they arent expensive so just change that out maybe its bad . Let me know what happens.

Also, whats your temp. reading? Is it holding normal? You might wanna get an integra radiator in there fast, but i've had 2 b16's and 1 LS/VTEC and none of them had thermostats. My VTEC always worked fine.


[Modified by CopperSol, 3:24 AM 4/4/2002]

 

The ecu is straight from the box. I didn't touch it yet.... haven't had a chance to. The car hasn't been on the road for more then an hour.

I know exactly what o-ring you are talking about.... I took it out to make sure the screen wasn't cloged or anything. I have the GSR radiator ready to go in... I just have to stop being lazy and make the lower mounts.

Anyway, Thanks for your help!

 

Running with no thermostat is asking for trouble. The thermostat is there for a reason. What you should realize, is that the coolant needs a chance to absorb the heat from the engine....it can't do this if the coolant is always flowing full speed. The ECT might be telling the ECU that things are dandy....but like I said earlier, the coolant hasn't absorbed all that much heat....so it does indeed look cooler to the sensor, but your engine will be hot.

Now, as far as VTEC is concerned: You need oil pressure, warmed up engine, and road speed to be >?mph (functioning VSS) for VTEC to engage.

There have been several posts about the criteria for VTEC engagment and oil pressure alone will not kick it in.....but I'm unsure of the mph requirement.

 

I fully unstand why the thermostat is there. I did it as a temporary messure until the larger radiator is in. It's not being driven very much (like I said, less then an hour in the past 4 weeks).

Now to the vtec.... when I'm testing this the speedometer is reading 45-55mph and the tach is just past 7k when it engauges. If the vss was shot wouldn't that cause the speedometer to not function?

-
Frank

 

19 MPH...

 

30km/h

 

If you can try to get a P30 ECU just to see if it makes your VTEC engage rite. If so then it's most likely your Hondata.

 

your coolant must be at least 100degrees before vtec turns on.
put a thermostat in.
now.
trust me. ive gone through ALLL this **** in my car.