amoebiasis

Hi everyone. I need some help with my car. I'll be pretty detailed, skip to the bottom for a summary if you dont want to read all of this.

I have a 95 civic coupe with a 96 B18cR swap. Today as I was about to leave work, I noticed that the idle was pretty high. It ended up climbing up to around 2k and started to pulse up and down a little. Considering it was pouring rain, getting dark and I was 45min from home, I decided to go ahead and drive home and mess with it tomorrow. As soon as I started driving off it started jerking so I stopped and the idle was now jumping around between 100 to 1100 rpm. I didn't see anything wrong, and since I was getting soaking wet from the rain, I decided to go ahead and risk it and go home.

During acceleration it seemed fine, then when I left off the gas the rpms would jump around, either at very low rpms or at around 2500k. After getting on the highway I cruised at around 50-55 mph. So long as I had a foot on the gas pedal it would buck but not badly. If I let off the gas however, it started to buck very severely (felt as I was suddenly braking then accelerating quickly). After about 20 min of this, the check engine light came on. Whenever I put the clutch in the rpms would jump around at around 3k rpm.

The codes I pulled were codes 8 and 14, TDC sensor and IAC valve. I checked the dizzy connector and saw that there looked to be a little bit of oil on it. I traced it back to the dizzy cap, I took it off and there is definitely oil leaking inside of the dizzy. Could this cause the problem? Maybe oil got on the sensors or something? Could the IAC valve affect the engine this way? I thought it just controlled the idle speed while it was cold, lowering the idle after warming up.

I will dig into it tomorrow, but I wanted to get some opinions on possible causes.

Also I should note that yesterday on the way home I got stuck in stop/go traffic and my engine began to overheat. I pulled over immediately and turned the engine off. The temp gauge read around 3/4 up at the highest point. Discovered that the radiator fan blade fell off of the motor shaft (aftermarket mishimoto slim fan). I fixed it and refilled the coolant with 50/50 antifreeze mix. It drove fine after the fix, and this morning to work, and all day today. I am planning to do a compression test tomorrow.

Thanks for the help!

tl;dr: Civic with B18cR swap developed very sporadic idle and would severely buck while driving. Threw codes 8&14. Found oil inside of dizzy cap. Overheated the day before but was fine after being fixed.

hybridmiklo

check to make sure there is a good ground and battery voltage at the iacv. start there. that will be the idle issue you had. the bucking issue will be the dizzy

KnucklesTheDC2

I'm having exactly the same problem, same cel, same bucking when in gear and same idle. It's intermittent but when it's raining or after a wash it seems to happen indefinitely.

Got a 94 Integra b18b2.

Did you end up fixing it?

amoebiasis

Yes. It turns out there was water getting into the ECU. Since you mentioned that it happens when it rains I would check that first. Water was leaking through the sunroof and running down the pillar and down the harness to the ECU. I fixed it by simply flipping the ECU around so that the connectors are facing down and I have basically a drip loop in the wires. You can also check the connection at the distributor to make sure that is ok.

Hope this helps.

KnucklesTheDC2

Man that's exactly what I thought, I checked the ecu and there's corrosion on the metal and signs of water leaking.
I've been trying for months to figure it out, can't believe we had the same problem haha.
Can't you replace a seal somewhere? Otherwise it will keep flooding into passenger footwell?

amoebiasis

I actually haven't tried fixing the leak yet. For my car at least, I think that the drain from the sunroof might be clogged and needs to be cleaned out. There is a tube that leads from the sunroof and ends behind the fender (I think) and from what I have heard from others it gets clogged and causes water to leak into the car. Whenever I am not feeling too lazy I am going to run a wire or something in there and see if I can clear it up.