Ok, so as some of you know I have a ls/vtec in my SI. It's a 82X89mm ls block with a usdm b16 head. Endyn pistons at 12:1. Tuned on a p28 with s100.

Here's the problem - when I switched from my jdm obd2 p73 ecu and vafc to the p28 it ran fine for about a day, then all of a sudden it started cutting the fuel at WOT when VTEC should engage. It only does it at WOT (well actually pretty much anything over 90% throttle) and it only does it over 5200 rpms. (vtec) It TOTALLY cuts fuel too and throws a CEL. The fuel cut is hard enough to throw me against my seatbelt. When I let off the gas the fuel comes back and the CEL goes off.

I took it back to my tuner and we street tuned it. Well with his s200 plugged in it runs fine. WOT pulls no problem. Plug back in my s100 and I take it down the street... its fine!? I seriously make about 20 WOT pulls to make sure it's fixed and we decide it was a loose conection. OF COURSE I make it about 3/4 the way home and it starts cutting out again.

Any ideas? VTEC pressure switch is dissabled, lol yes I have oil, and I have a VAFC hooked up with no setting on it.

 

Bump for ideas

 

Take out the VAFC, why the hell would you want that if your running hondata anyways? Do you have a new fuel pump and filter? Follow the fuel path onto the regulator and then if none of those work check your main relay and replace it. You might as well since after 10 years, it's unreliable, worn out and easy to replace. The main relay can give intermitent performance to the fuel pump it powers. $70 honda parts counter.

 

get rid of the vafc and buy your tuner's s200

 

u might have a wiring problem.. it happended to me.. never found the culprit but after re-doing the harness its been running fine since... u might have a broken wire somewhere and its grounding itself making ur ecu trip out

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g0tuj0ckin &raquo;</TD></TR><TR><TD CLASS="quote">u might have a wiring problem.. it happended to me.. never found the culprit but after re-doing the harness its been running fine since... u might have a broken wire somewhere and its grounding itself making ur ecu trip out</TD></TR></TABLE>

I think this is what's going on. The problem is intermitent, and when I move my ecu around I can usually get a few good WOT pulls before it happens again. Stupid Hondas...

 

no its not stupid hondas.. its stupid motor swaps lol... u have to add wires and sometimes they get loose

 

Datalog your TPS percentages. It may not go beyond 106%, It will go in to a cut out mode otherwise.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2LEM1 &raquo;</TD></TR><TR><TD CLASS="quote">

I think this is what's going on. The problem is intermitent, and when I move my ecu around I can usually get a few good WOT pulls before it happens again. Stupid Hondas... </TD></TR></TABLE>

you're using an OBD2-OBD1 converter harness, you might wanna start checking there first.