[RESOLVED] O2 volt at 1.0v + stuttering and bucking

[numlock666]

The Car:
Updated in profile:
95' TSI with 6Bolt, 16G, Stock Fuel System, GM MAF + MAFT.

Basicly it ran great for the last 7 months minus suspension issues.

Last saturday I was at a meet in Chino Hills, car drove out there fine and as I decide to go home, the timing belt jumped 3 teeth on the intake cam. Did a miraclel job there and got it to jump back 3 teeth. Fired right up and drove home. I noticed it felt lacking so I ran a Compression test and cylinder #2 registered 90psi. and 1,3,4 was in the 150's. So Thursday, took the head off, dissasembled it, took it in and got the valves changed out, seals recut and everything checked, slapped it back on with a new HG, already had the ARP's. Re-did timing and got the tension perfect this time because I have the tool now. Car fires up first try, all in one day =). Today Just did a compression test and I'm getting 155 153 150 157 #1-4 so all is good.

Heres the problem, I'm running rediculously rich, the O2 pegs 1.02v HAHA! It stutters, bogs, misses bad. The O2 still cycles though and if I gas it up slowly it cylcles normally but up until around 3K it starts to go up into the .9v's.

Things I've eliminated:
NOT BOOST LEAK. Why? Im running a dummy turbo, no boost at all because Im having the 16G rebuilt. Also running a blow through and everything is metered right before the TB. Checked the fuel return line, all looks good, no kinks or frays. I have the vac line from the mani to the FPR directly. Plugged in a logger to check for codes, none at all.

Things I'm going to check today:
TPS- mine is kinda ghetto rigged and I remeber when I had it on backwards after finishing the 6bolt swap I was getting this same scenario. O2 sensor - Kinda old, was chewed up by the 14B when the turbine wheel and compressor wheel seperated Haha. Clean out the MAF. Also, the FPR soon as I get a chance to borrow one from a friend.

Im sorta leaning towards the TPS because 1, It happend before, and 2 what I mean by ghetto rigged, I was fixing the shafts seals and was putting it all backtogether, dropped it, broke the TPS's male connector off. Soldered it back together and superglued the casing HAHA. But in the process of removing the fuel rail, #4 injecter popped off and it sprayed fuel on the TPS and some of the cover is missing =(

Update:
New OEM O2 sensor, still 1.0v+, funny thing is the car runs better with the o2 sensor plugged in but now installed in the O2housing. Just hanging around.

 

[Mikael SS]

i see .9v at 14.3AFR

I don't know why people continue to think that the factory O2 sensor tells you anything.

 

[numlock666]

I'm not saying that it's my excact AFR, I know that a norrowband is not something to rely on for accurate AFR readings but it's obviously rich. Doesn't matter what the narrowband says, if its popping and bucking and shooting out flames....I think I'm a bit on the rich side. If you don't have anything good to contribute to the thread, or even this forum for the most part, don't say anything at all. Just a waste of space and more crap for people to search through for pointless information.

 

[numlock666]

On my way to work I was watching the logger while keeping at a steady cruise rate of 40mph at around 2000 RPM and made an interesting observation. At that load, the car was pulling 2-3 g/s of air, but from time to time it would jump to 12-14 g/s randomly and that was about the same time the car would buck and stutter. So I started suspecting the MAF sensor due to it acting strange the same time the car would go haywire. Took it off and it was dripping with oil. My guess is that the oil collected in the FMIC from the last dead turbo finally made it up that 90* bend into the upper IC piping and got to the MAF. Cleaned it with some Electric contact cleaner, hooked it back up before the TB and left the rest of the IC piping disconnected (RAM air style) and it runs perfect! For being a N/A 7.9:1 compression ratio engine at least. HAHA...will be putting on the borrowed 14b tomorrow hopefully.

Mods please tag this as SOLVED