thebeard

Okay so here goes.

A couple weeks ago I picked up a 95 civic hatch with a non vtec b18b1 swap obd1 p75 with a tuned chip. Engine was completely redone before swap about 10,000 ago. New everything, mostly JDM parts but also performance pistons, cams etc... new type R tranny.
So, anyways. About a week ago I was getting a little feisty with it. I pulled out from a stop slowly then quickly rolled into it spinning tire until redline in 1st where I slapped it into 2nd. When I hit 2nd, the front end started hopping, it hit pretty hard 2-3 times before I mushed the clutch and started driving like a good citizen.
When I started driving normally my mil light popped on. I'm a mechanic. I work at a shop. I came back from lunch threw the scanner on it and got these three codes.
MAP sensor high voltage
TDC sensor no input
ECT sensor high voltage
and i got an obd2 code number P0662. After the number it read "Unverified code"
I looked it up online- "IMRC valve position sensor high voltage"

I checked all my grounds. They're all solid and have resistance(no breaks). I checked the ECT sensor, it has 5V going in and I believe .3-.4V at running temp. Which tested as normal. I tested the map sensor. 5V from the pcm 2.87V KOEO KOER between .8-1V. Pretty normal. checked resistance through the TDC plug on the dizzy. All wires had resistance. That p0662 kinda threw me for a loop, not quite sure what to do there. I rechecked all the sensors, rechecked the grounds, pulled the ecu out opened it up and made sure everything looked good. no burn marks, SST chip was still in place, pulled it out and looked at it. No burn marks or anything. Re installed it put the ecu back together plugged it in bolted it up and I'm still getting the same 4 codes 1-3 seconds after engine startup. Without fail. Engine runs fine, smells a little rich when you hop on it but it starts up with the first turn of the key. No extended cranking. My only thoughts are that I broke the ecu with the hard hits.

Sooo, any bones you gurus could throw me would be great. also would going through these diagnostics help my case at all? https://honda-tech.com/honda-civic-d...ignal-3245627/

Thanks for any and all input.

tony_2018

obd1 shouldn't throwing obd2 codes.

MAP should be at: Ignition on 3v, at idle: 1v
ECT should be at: varies from .1 - 4.8 depending on coolant temp.

Technically a wire is shorted somewhere.

thebeard

Map was acceptable. ECT was within range.
I'm gonna go over my wiring diagrams tomorrow.
Also about 2 weeks ago the o2 plug extension melted onto the exhaust and blew the 15A ecu fuse (forgot to tie it up after put it on, dumb mistake) pulled the wires apart and taped them separately then taped around the harness. Put a new fuse in and ran flawlessly. Check engine light didn't come on until after the 2nd gear hop.
Do you think that has anything to do with this problem? I made sure to tape the wires individually and cover up all open/frayed wires so there wouldn't be any contact. I know it sounds stupid but I figured since there wasn't an o2 code it wasn't the problem.
I'm gonna be pulling that section of harness apart this week.

(edit: wording)

Former User

Reset the ECU to see whether any of the codes repeat.

thebeard

I've reset it at least 5 times. All 4 codes have repeated each time.

I just took out the o2 extension and pulled the plastic conduit off of the wires, looked at all the wires and tugged on the places I taped to see if it was weak and would break. None broke and they all seemed strong. re-installed it. Turned the car on to pull it out of my garage to take to the shop tomorrow to check out. Ran for about 2 min, no mil. If it doesn't come back I'll order a new o2 extension. If it does come back I'll have to pull the harness apart.

(edit: wording)

thebeard

Mil is still off after approximately 50 minutes of driving and two trips. Looks like I'll be buying a new o2 extension plug.
Thanks for all the help gents