SiCivic99

Ok. Here is the deal. I have a 99 Si with Greddy turbo kit. I have thermal exhaust, test pipe, Turbo XS BOV and a recently installed LARGE Greddy FMIC. I was also running an Apexi AVC-R.. Now you know the good stuff up front, here is the deal...

I blew my engine. Rebuilt it with stock internals. I used assembly lube on the pistons, put it all together and fired it up. All works fine there. (its a detail I had to include)...

I noticed when I first fired the new engine the air/fuel ratio gauge was acting very odd. It was SLOWLY sweeping in stoich on a cold engine. Odd. Anyways, it went away and started working fine. I notice one other time that it did this so lets say twice in a 1 week period. My intercooler showed up so I installed the intercooler and I pulled the AVC-R out the same day because I sold it...

Now, my BOV sounds TOTALLY different, as if its not even working and I have compressor surge, but other then that the car appeared to work fine. I drove to work no problems, maybe 20 miles. I got off work @ 10:30 and it was cold outside (if this matters).. I fired up the car, the air/fuel rtatio gauge went rich, then slowly crawled down like it usually does. I got on the road and went maybe 100 yards and BAM, it drops off full lean. Nothing. When you rev the car, nothing. I went home and got code 1 (primary O2)... I checked all my connections, all looks good. Nothing is loose, all connections are soldered and tight. I reset the ECU, drove twice and then got the light again. Car STINKS rich as hell, but keep in mind I have a test pipe. The test pipe was on the car for about 2 weeks before I blew the engine and I NEVER got any O2 cels, just something about the cat being 'below threshold' (code 67 I believe).. I tested the O2 sensor like I was supposed to according to helms. I disconnected the O2, idled the car and took a reading off terminal 1. I got .5 volts, when I revved the engine it shoots up, then goes down and rested arround 0.01 volts (this was a COLD engine).. the book said if its ABOVE .1 volts then its bad and to replace it, mine passed so I assume I don't need a new one. I replaced the ECU also like it said and I get the same results. The car began idling very rought and was going up/down, up/down from say 600-1000 rpms. Again, this was @ night when it was cold. Interesting thing is the next morning around noon I reset the ECU, let it idle and had no trouble. It tossed another code 1 within 2 miles of leaving home. Last night the air/fuel ratio gauge began to 'sweep' in a SEMI-normal fashion from stoich/lean, but it would never show rich. It would only show rich when I first started the car, and would then go down to lean within 10 seconds.

Now, someone else on clubsi has the EXACT same problem with thier Greddy kit. I figured it was the blue box, but I disconnected that and idled the car with the same results. This other person also has replaced his O2 and still has the same problems.. I have replaced my ECU and I still have the same problem.. Greddy has no advice for me, they say an intercooler couldn't do that. There are a few things I am thinking could be my problem...

1). I have a plugged up O2. The teflon in the engine assembly lube has plugged it up and is causing it to give jacked up readings.

2). I have a wired or something that I knocked loose when removing the AVC-R. I have checked my connections, but that doesn't mean there is NO error.

3). The intercooler is introducing a much colder charge. The car is confused and is trying to somehow compensate. (I seriously doubt this, but hey, I am just throwing out ideas)

4). Somehow the Greddy blue box has messed something else up. Who knows what, but its an idea.

Keep in mind this engine is basically new. I am still breaking it in. Therefore, I have not boosted it, I always shift @ 3,500rpms also. Maybe this has something to do with it? I don't know.

Any ideas/advice?

SiCivic99

TTT

HondaCutter

Hey man, how's it goin. Anyway maybe you should try replacing the O2 sensor, and the IAC valve. Just throwing out some ideas. The surging sounds like the IAC valve but, or you may have a vacume leak somewhere.
Later

SiCivic99

But after resetting the ECU in the morning, there is no more surging @ idle. My code is code 1 (O2), not code 10 (IAT)... Vaccum looks good on the boost gauge. It sits @ 22 now, 18-19 before the engine rebuild.

HXMan

Definitly get that O2 sensor replaced. It probably is gummed up with something. It is kinda cheap to replace, and at least then if the problem goes away, you know what it is. I know when I get codes with my car, it usually idles pretty good, until it throws a CEL. Did you get a CEL today after resetting the ECU in the morning?

Seems to me like you tried everything else, and your sensor is to blame.