Ok guys, I recently pulled an LS/VTEC turbo build from one civic, and put it into another civic of the same year (95 EX). Engine ran fine when pulled. I used the same engine harness from old car, and just hooked it up the the shock tower plugs in the new car. I have a P28 chipped with a Hondata S300. Car was tuned, and ran good. I used the same ECU in the new car.


Once swap was done, the car started and ran "ok". It felt the same as old car, but had a bit of a stutter or miss. No big deal, I was gonna get it retuned and figured out.


Anyway, I've driven the new car through about 5 tanks of gas. No major problems. I stopped for a bite to eat one day, then started the car up and went to pull out of the parking lot, and the car stalled. The Check engine light came on solid. (keep in mind, at no other time has the CEL come on)

I try to restart the car. The main relay works fine, the fuel pump primes, the CEL comes on, and clicks off for a mili-second after fuel pump prime (like it always does), but now it stays on. When the engine cranks, it acts like it gets no spark. I figure it's the ICM gone bad. I've dealt with that before. But I've never had a solid CEL. I tow the car home, start checking everything out. Here is what I've done, and I need opinions:

when the key was in "on" position, the IACV would buzz. Constantly. I've never heard this before. The CEL stays on solid, and no codes are thrown. When a laptop is connected to the Hondata, it won't show any codes either.

I try unplugging the MAP sensor, CEL still on. I unplugged the IACV for a moment, and believe it or not, the car started up. Very poorly. I had to keep the gas pedal down for it to run, and it was running very badly. Like it would if it were on 3 cylinders. Still, a solid CEL. I've tried to replicate this, and I can't get the car to start anymore.

I checked all grounds, they seem fine. Fuses seem fine.

I put another P28 in the car, and the after the fuel pump prime, the CEL turns off as normal. I can't get the car to start though, I'm thinking due to the 780cc injectors, the GM 3 bar map, etc. BUT.... the CEL does turn off with a different ECU.


Ok, so is my ecu bad? What could cause this? Do you think my Hondata is still OK? I mean, could I swap it into another P28 and be good to go? If the whole thing is shot, thats a shitload of money to replace. Can anyone give advice, before I buy another ECU? Also, whatever made my ecu go bad (if that's the problem) is it just going to happen again with the new ecu? I don't think it's the ICM, because the ECU shows a solid code before the car is even tried to start, and of course, I did get it to start briefly with the "thought to be bad" ECU.

 

new revelation.

the hondata ECU plugged into another car (stock integra GSR) will start that car up. The CEL stays on and solid though. I'm gonna try to hook up my laptop in that car, and see if I can get it to respond to anything.

I wonder... could the installed parts that allow the Hondata board to work have gone bad? I mean, the ECU has basically reverted to a P28 now? The solid CEL still has me baffled.

 

Same thing just happened to me, iacv buzz and all. I replaced the main relay, which stopped the buzzing, and the solid check engine light means that something is wrong with your ecu. I would replace the main relay and the ecu.

 

what was the code on the CEL???

 

i actually recent started having the exact problem over the past 2 days in my ef hatch. i didnt have any cels.then im just cruising down the road and all the sudden car dies and soild cel. but then i pull over try and start it right away it wont start, fuel pump primes, then i wait 5 mins try again it starts and runs fine. but today it happened to me and i hust turned the ignition back then foward again while coasting in gear and she fired up. for some reason im starting to beleive its not getting enough spark but has new dizzy wires and plugs and the issue for me comes and goes so maybe its just a short somewhere.

 

I just got done with this same issue. My chip in the p28 ecu was bad. happened right after my swap. would run for a couple minutes, then die, everytime. would go into safe mode, iacv would be buzzing etc etc. the chip may have been shorted out or something. or was just a cheap one.

 

^

I wish that were the case. My chip was a Hondata S300. Not so cheap. I'm going to cut the J1 jumper in the ECU (making it a stock P28) and run it in my integra, and see if I get the solid CEL. If I don't, then it's either the Hondata, or the parts that were installed on the ECU to attach the Hondata.

Strange thing is, it's ran fine for 4 years. Why a problem now? WTF? Nothing has changed.

 

this just happended to me and i had to replace the plugs wires rotor bud/cap and distributor

 

^

that wouldn't explain the solid CEL with no codes. I know that the problem lies in my ECU. I'm just worried that when I replace it, something in the car is causing the ECU to go bad or something, and I'm gonna end up frying the new one too.

 

im having this prob to only with a h23a vtec. with my stock p06 i get code 15. with my chipped one i get none. and my ems shows nothing but cart wont start with any of them. turns over fine but wont fire. i changed the rotor, coil and icm but will not start

 

^

is yours getting fuel?

 

yep. took out sparks to verify injectors were actually sprayin. bottom of each one was wet