q.man06

2000 ex coupe
Built D16Y8, with all stock ignition/timing components
Hondata s300 on a P28


When in neutral, you can get the engine to rev up to ~4k rpm, but only for a second before it cuts out. Likewise, if you hold the engine RPM at anywhere above 2k rpm, it will only hold for a second before it cuts again. Once the car returns back to idle, you can do it again. It does not sputter, it's like you just hit a brick wall

When driving, if I keep it under 2k rpm, I can drive it just fine. Anything over that, I have to let the engine come back down to idle before I can start driving again.

A while back I got a code for the ignition signal, and I fixed that by plugging the wire back in--- figured it's not important as this happened about 3k miles ago, but the more info the better.

Car is not throwing any engine codes. Lean protection is disabled, rev limits set to just over 7k rpm.

Any idea's would be greatly appreciated.

Jimster480

Sounds like its going lean. Your saying its a Built D16? If you increased your compression then that could be the issue. Also it could be the TPS or MAP sensor malfunctioning. If you dont send enough fuel/timing for your RPM then you will hit a wall. When I put this setup together that I have now, my car was tuned for a built D16 with 7.5 CR (vitaras). Now the D15B that I have has 8.7. it ran so lean that it would feel like it hit a wall. I adjusted my fuel pressure until it ran fine.
Do you have a fuel pressure gauge?

q.man06

It's an FTJ vitara build, so ~8.5:1 compression I believe.

The wideband doesn't read lean at all, It's actually in need of being leaned out but not by much. It sits between 13:0 and 15:0 at max between the two.

I understand not having enough timing/fuel will cause you to hit a wall, but as i've experienced it, it usually just leads to sputtering/misfiring. The car doesn't miss at all, it feels just like you hit boost cut, or lean protection where you have to completely back off the throttle to even use the engine, just with this it wants to get completely back down to idle before giving you control.

MAP sensor could definitely be an issue; however, I thought it would have thrown a code? I have the GM 3 bar map sensor, but in hondata I set it up slightly differently by changing the offset-- Reason for this being, is that i'm in Colorado and with the altitude it reads ~2psi off. So I moved the offset to compensate to where my datalogging matches my gauge.

i'll go datalog the TPS to see if there's anything funny going on there.

I appreciate the input

Jimster480

FJT custom length rods? Becuase if not then its 7.5:1 on a z6 head.
And it shouldnt be falling on its face for 13-15 on the wideband. it could be the wideband though.

q.man06

Figured it out. Somehow the TPS got unplugged, really not sure how lol. I'm surprised that it didn't throw a code :/