guvnerH

I've swapped a JDM D15B VTEC into my 96 Civic DX and since then the car just won't run well.

Here's a little background info.

-Using P08 ECU with obd2-obd1 jumper harness
-Swapped Y7 distributor internals into the OBD1 distributor housing, prior to this I was using the TD-42U dizzy and I had no spark, after swapping internals from the working Y7 dizzy I have spark. I didn't buy a dizzy jumper harness but have checked 5 times that the wires from the harness to the dizzy are correctly matched up.
-Converted the IACV wires from 3 wire to 2. Black/yellow wire shows 12v. I have also moved the A14 pin to A12 on the factory harness and removed A13.
-Using Y7 injectors since I'm still using the stock engine harness from the car.
-VTEC is wired up
-Spark plug wired have been triple checked and are properly hooked up to the dizzy.
-Dizy is not 180degrees out
-Timing belt marks are all lined up
-TPS, MAP and IAT all work and are plugged into the right sensors
-NO CEL codes!


So starting the car using the OBD1 P08 ecu the car starts right away, but struggles to idle, the intake is making a loud sound which is coming from the IACV, if the IACV is unplugged the sound stops, but the car will drop RPM even more. Regardless of the IACV if I hit the throttle lightly or hard it just bogs, if I take a few seconds and slowly feather the throttle higher it will rev up, suddenly rev nice and high but then gradually drop back down to a rough idle EVEN with the throttle held in the same place. Plus the car is running pig rich, there was a 2 foot long black gassy mess on my garage floor.

After trying various things to get it to run just out of desperation I plugged in the Y7's ECU and suddenly the car ran pretty darn good! The idle was low and kept stalling because the IACV was not wired to work with this ECU as its wired for a 2 wire plug, but if I held the throttle just off idle it ran nice, I could even take the car for a drive around the block and it accelerated fine. Now I was getting codes for crank position sensor, O2's since I'm using a post cat O2 for a pre cat, and IACV

I had a friend come take a look at the car since he is more knowledgeable with Honda's than I am and he said everything looks fine to him, but can't understand why its not running on the P08 ECU, but runs OK on the Y7's ECU.

The only thing I can think is that I have a bad ECU, but I wanted to get opinions from anyone willing to help before I try to find another ECU.

Thanks in advance.

Ryan

guvnerH

bump

guvnerH

anybody?

guvnerH

UPDATE:

I know I'm the only one talking here, but hopefully someone can still try to help me out here.

I got the car to run with the P08 ecu, it took letting the car warm up and revving the engine a few times to get it to work, I took it for a short drive and everything seemed fine, VTEC would kick and it pulled ok. As I got further into my drive it started to buck and bog, when I stopped to turn around the car bogged horribily from a roll and I had to pull over and swap back to the OBD2 ecu to get home. I then was able to borrow a working P28 ecu and it was much of the same althought it did feel stronger, VTEC hit much harder, but when I got futher into my drive the same thing happened. The one difference was that once I got the revs up into VTEC it pulled hard to redline, but getting there it bucked and bogged. Then I did the same drive with the OBD2 non vtec ecu from the d16y7 and it drove great, not one problem the whole drive.

Now suspecting the jumper harness being the culprit i checked all the wires via ff-squads site and everything looks fine, there were 2 power source wires crossed, but uncrossing them yielded no change. I did notice on the OBD2 side that 2 pins (iacv) I think A12-A14 were spliced together going to the one 1 iacv pin on the obd1 side, that I have yet to look into.

Does anyone have an ideas here? i'm desperate to get this car going as my wife needs it to get to work daily.

bordeaux37

I'm having the same problem. But I also have an extra plug, and cannot figure out where it's supposed to go. There are three identical plugs, just with different colored wires.
One goes to the Fast Idle Control, one to the MAP sensor, and the other is a mystery. Which goes where?
Plug 1: Yellow with red stripe, green with white stripe, white
Plug 2: Yellow with white stripe, green with white stripe, red with blue stripe
Plug 3: Yellow with green stripe, green with blue stripe, pink with white stripe.
HELP!