I have a 93 EG with a B16a2, skunk mani, and skunk tb.
Did the swap myself.

It's running s300 on a p28.

Ever since the first day I got the car running with the new motor, there is some sort of fuel cutoff issue.

The fuel pump is a new walbro 255. Here's what happens:

If you hold the throttle in one spot, every 3 or 4 seconds, the fuel pressure completely drops, so the motor bogs down. It does this when driving or just sitting. And it will do it constantly if you hold the pedal still. It does not do it when accelerating or decelerating. It ONLY does it when the pedal is held in one spot for a few seconds.

It's basically like....VRRRMMM-bog-VRRRRMM-bog-VRRRMM-bog (it will do it as long as you hold the pedal still)

When it's hooked up to my laptop, I can see all of the fuel pressure drop as soon as it does it. All of the plugs and everything were checked by the dyno shop that installed hondata.

I am thinking it's something to do with the fuel pump. Anyone have any similar issues or ideas?

Thanks.

 

If you are seeing a drop in fuel pressure....it could be the pump
but it seems weird that its only when the throttle sits in one spot for too long.

Throttle Position Sensor? I think its supposed to be .45v at idle
and no higher then 5v at Wide open Throttle. You can check it with
a multimeter. Not sure if a bad TPS causes drop in fule pressure but
I know sometimes TPS can go out and cause hesitation (which could
be fuel pressure change)

I would check all sensors on and around throttle body and if that doesn't
work....then I would take the stupid gas tank out and have that new pump
checked. But i don't think its a fuel pump (b/c its brand new)

 

And you said you had the p28 dyno tuned......right? So they would have adjusted the air/fuel ratios and that can be eliminated as a problem

 

yeah, it was tuned the same day they installed the hondata.
they didn't notice the issue until the next day when I brought it back and told them about it.

they had it for the day and ended up telling me they couldn't figure out what was causing it and that it could possibly be the TPS.
so i put a TPS on from my buddies car, and it made no difference.

 

But did you adjust the TPS correctly when you swapped it?

 

It was a while ago, but I know I checked the voltage and made sure it was .5v at closed throttle and 4.5v and full throttle.

I honestly don't think it's the TPS. I am going to pick up a new fuel pump tonight and see if it makes a difference.

 

usually when I have that problem it's the plugs/wires.

also, you check your fuel pressure regulator

 

Have replaced plugs and wires, and it has a brand new AFPR.

Went out and replaced the fuel pump tonight. Same issue.

It does it if you hold steady anything over 2k rpm.
When it does it and I datalog it, Injectors and Duty drop to 0. Then they go right back to normal, then 0.....(rinse, repeat for as long as you hold the pedal still).

I also notice that they drop to 0 if I just give it one good rev and let go. As the rpms drop, the injectors and duty drop to 0.

TPS is reading correct voltage in hondata.

I really need this crap fixed. Any other ideas?

 

bump for knowledge

 

what ecu are you using? i had an issue with both a p72 and p75 with datalogging. tuning on CHROME, tho. when i would turn dataloggin off it would quit doing it. i went through about 3 sets of dsm 450s and finally pulling out of the driveway i turned DL off and it ran like a champ

 

It doesn't just do it when datalogging. It's done it since I did the swap. Even before hondata was installed on my stock p28.

 

bump.