lostshootingstar

I recently put a 96-97spec JDM ITR motor in my 2001 GSR. Using the JDM ITR ECU that came with the swap (from hmotorsonline). it reads P73, so i know its the right one. Also using the Obd2b -> obd2a conversion harness.

The car runs perfectly, no CELs.

The problem is that there is a VERY aparent fuel cut at about 6000rpms. The previous owner of the car had installed a stupid VAFC, and when i set the VTEC engagement point below 6k, VTEC kicks in, and then i "hit the wall" so i know the solinoid works, but i dont think the ECU is ready to let VTEC kick in for one reason or another.

I have read that if the ECU wont let VTEC kick in (even though the AFC is activating it), then it will setup a rev limit, close to 6000rpms, so im assuming this is my problem. but i dont know how to fix it since i have no CELs.

here is a little history of the swap.

1. put the motor in, started it, it ran like crap, threw a bunch of codes.
2. replaced the TPS, 1 code fixed
4. IAT sensor was broken, replaced it. code fixed
5. car ran perfect, and still does 2 weeks later.
3. VSS was broken, replaced it. Another code fixed

the VSS was the last code i had to clear, and its no longer showing up. I cleared the ECU by pulling the battery cable and "backup fuse". I figured the VSS code was what was telling the ECU to setup this fuel cut, but now that its fixed, it does the exact same thing.

iv read a lot about oil pressure causing this. I have put just about 500miles on the car since i put the new motor in, and the oil is 1/16" up past the second dot on the dip stick, so i dont think this is the problem.

Im going to try and disconnect the VAFC thats installed, but i have to wait for the weekend

please help! not being able to go past 6k on an ITR motor is hell!

project_hatch1.8

You don't have an msd ignition do u?

lostshootingstar

No, everything is stock. except the VAFC. however, everything was working fine with the GSR engine.

Another problem i was having is that my fans wouldnt kick on. I played around with the coolant temp sensor, and finally got them to kick on, but i havnt heard them in a while. would this effect VTEC engagement? my cluster shows that the car is running at operating temp

lostshootingstar

Ok, a new update on this:

I setup my VAFC to show both VTo and VTi. and they BOTH come on, so i dont think the ECU is the problem anymore.

on the other hand. even though there is no CEL, and the car works great until 6k, when i jump the ECU for codes, the light stays on (code 0). i cant remember if thats what its supposed to do, or if the light is just not supposed to come on at all.

what else could be causing this? iv read alot about the ignition system causing it. so im going to replace my plugs, wires, cap and rotor

JDM_Ej

Wideband? I had this problem, and it turned out to me my map sensor.

lostshootingstar

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM_Ej &raquo;</TD></TR><TR><TD CLASS="quote">Wideband? I had this problem, and it turned out to me my map sensor. </TD></TR></TABLE>

Interesting...the TPS was broken, so i guess it makes sense the map sensor could be screwy. ill try putting my old GSR one on.

lostshootingstar

I figured it out!

im almost embarrassed to post this. but i figured out what the problem was today. the engine has probably revved past 6k the whole time, however, the TACH does not go past 6k. I was subconsciously taking my foot off the gas when i would see the tach bounce around. so today i said "whats the worst that could happen if i keep my foot on the gas" and sure enough, i saw at least 8k on the VAFC before i let off.

so, next question. why would my tach drop to zero after about 6k?? ignition control module?

so lazy

you got it buddy! but on a previous post i a guy's tach was jump'n i just told him to change the whole dissy fixed his problem.. saves time