when vtec hits it sounds like rev limit!

ok heres the setup i just put together for my friend and i am not a electrical person so help me out
s2 s2'2 ctr head full skunk v-train
eagles with high comp endyn pistons
81.5mm and like 12.0-1cr in a ls block
i am running the vtec straight out of the vafc and bypassing the whole p28 vtec engagement, because i tried it with it looping through the ecu and it did the same thing, so any suggestions would be worth hearing. i know the head and everything in it is good because i was making 220 horse with that head on my old setup, and i know his bottom end is fine because i put it together a few months ago with a ls head that he has been running

also if you completely unhook vtec it runs just fine all the way past 6500 and then i let out of it

 

bump

 

Re-check all connections for v-tec controller, something may have high resistaNCE IN CONNECTION. Especially double check the connection to the v-tec oil pressure sensor for the ecu. I would rec running control through the ecu as originally intended by the controller.

 

I got a wiring diagram of the ecu harness and the only one they had at hybridgarage was for a P72. The color schemes are different from the diagram from the service manual for a car

 

bump that $^!&

 

To the top. ANYBODY

 

definately sounds like the vtec oil pressure wire on the vafc

 

dont know if you have this diagram for the p28 hope it helps. Good luck

 

are you sure everything for the v-afc has been hooked up? i remember hearing the same problem and it was withe the vafc a wire wasn't hooked up right or somehting. sorry i can't be of complete help.

 

I'm using this in a 93 Integra LS. There is no oil pressure switch wire in the harness or vtec solenoid wire. I ran a new wire to the solenoid and connected it to the pink wire from the vafc.

 

The P28 needs the connection from the Blue wire on the V-AFC. The ECU thinks the Vtec didn't activate correctly, because the ECU is not getting the pressure switch signal (this is supplied by the V-AFC through the blue wire), and the ECU is having fits over this, and causing your problems.

 

What does the blue wire go to on the car. It's the VTM signal right?

 

Every different wiring possibility and no change. At narrow throttle, it will rev as far as you want it to go without vtec. If you floor it, it bogs out at vtec whether its at 4800 or 6000

 

Just be sure the blue wire goes to the ECU, and not into the chassis wiring harness. Also, be sure you have the purple V-AFC wire connected to pin A4 at the ECU. You also need to cut the wire from the ECU to the Vtec solenoid. So pin A4 from the ECU goes into the purple wire for the V-AFC, and then the pink wire goes to the Vtec solenoid on the motor. The blue V-AFC wire goes to pin D6 at the ECU, but has no connection to the engine (not required).

 

Cool. Got that. What about the white and yellow? They loop in the pressure signal, which on my car is the map sensor

 

If you want to change fuel with the V-AFC, you need to hook up those 2 wires (yellow to the ECU and white into the chassis harness).

 

had that **** happen to me when i installed the vafc but not tune it. it threw a vtec pressure sensor code(?) and a too rich/too lean. i think these are probably causing you not to hit vtec, or maybe your O2 sensor is bad, but not likely. have you had it dyno tuned? i would spend the money and do it right.

 

At full throttle it wouldn't be the O2 sensor. The ECU ignores the O2 sensor after about 3/4 throttle.

 

I put the stock PR4 ecu in, messed with the ignition timing and the fuel, and it ran right. The P28 I have been using has a Jun style program in it.

 

Do you know for sure that the Jun program you are using if fully compatible with the P28 ECU? Has this ECU/Chip combination been used before?

 

No I don't. What about having the PR4 programmed ( by someone who knows what they are doing) and being done with it?

 

Why don't you try some other DOHC Vtec program on the P28 that you know will work with the ECU? PM me if you want to try this route.