Major RICH Problems...Full story inside, will investigate more soon
 

Hi all,
Well this roller coaster ride isn't over yet. I've been running John's custom chip/3" maf and 440cc injectors for about 250 miles/2 weeks now. It has been decent. Upon initial startup it would hardly hold an idle. I did a TBA and it ran somewhat better. It had a hard time finding and holding an idle (sometimes running at 200 or 400 rpm's until it would rev up and down between 800, 900 and 1000, and then hesitate and dip down). That has all gotten a lot better with time. On stop signs or immediate dips in revs, the car would really like to hesitate, occasionally stalling. It got annoying, but was livable, and like I said it was getting better.

I finally got around to installing the EGT. It is immediately post-turbo in the DP. I would see readings of 7-800 at startup idle. Once you hit the gas it would climb up to about 1000, and then when returning to idle it would stay at about 1000. The more boost, the higher it would go. I think the max it saw was about 1400.

Other recent problem: I tried plugging in my Vag-Com to do some logging of fuel trims and MAF readings. The light on the Vag-Com went green, but the computer kept saying adapter error - that it wasn't plugged in or something. I still am mystified by this. I don't know if it is a car problem or a laptop/interface problem. Recent additions include the new chip - hard soldered - (maybe one of the pins didn't get done right and it doesn't affect performance, just diagnostics?).
I also recently added an aftermarket radio. I did all of the checking on ross-tech's site, but it was inconclusive. I thought though, that if the light was green, I shouldn't have a K-line problem.

So, the car has been running pretty nice lately. I was about to take some fuel trim readings and then raise the boost from 8 to about 12, then eventually to 15 or so...until tonight.

I am driving around with one of my girl friends. I get to the left turn lane, but the straight lane just turned green, and we are just driving around anyways. I am maybe going 25 in third. I downshift to 2nd, and start to feel some hesitation. After this the engine is running like complete crap. The gas pedal is fairly unresponsive and the car is shuddering like crazy. I pull onto a residential street loop and make a couple of laps to see if it will go away, because I have had much smaller scale problems lasting no more than 5 seconds before. This was stuck for good though. I couldn't get it above 10mph and Heather was getting thrown all over the place. I pulled over. It was idling fine though.
One of the local mechanics and worker at O'reilly's came over (he just happened to be right around the corner and saw me) and started looking at it with me. We found a major fuel bog. The tailpipe was shooting out so much carbon and you could smell the gas. EGT's were about what they normally have been at idle. Under no load, the motor would rev up fairly freely and smoothly, but slowly. In gear, it wouldn't hold an RPM to save its life.

In our pathetic street light and late at night, I just nursed it home at 10-15MPH, shuddering like mad. I abused the crap out of my clutch too. Oh well, it's getting replaced anyways.
Another weird thing: My boost guage (Blitz DTT) has been reading 0.00 bar the past couple of times I started my car. I figured it must have just gotten disconnected somehow. On the way home tonight, though, it started giving vaccuum readings. Recently, I have been pulling about -.63 at idle (-.70 before the new programming). The whole way home, the RPMs would be shooting all over the place (800-4000, stall, pop the clutch, 3000,1200,etc), but the vaccuum was finding a weird number and holding to it. It would adjust every few seconds, but not in real time. Readings were from about -.28 to -.43.

I am quite lost, but hopefully something will pop out at me tomorrow. My first suspect is going to be cleaning the o2 sensors. Maybe running so rich for a while carboned them up too much. I'm also going to inspect all of the vaccuum and intake lines. Anything else I should check?

Blown MAF cause problems this bad? Anyway to check or just unplug and see what happens?
I would check to see which of the many DTC's have been thrown, but oh ya, my Vag-Com isn't working.
Also, randomly the CEL started flashing last Thursday. I pulled over, the car was shaking a little and misfiring every once in awhile. I checked the manual, kept driving, and it went away in about 3 minutes.

Thanks for all the wisdom...

Steve

Re: Major RICH Problems...Full story inside, will investigate more soon
 

Gonna take a few stabs. You still got that BPV in or you have a BOV on there currently? A lot of times stopping fast or hard breaking can cause a BOV to crack open and car to stall. Try another persons VAG and see if you get a ICM code(ignition control modual). The random jerkyness could be from that. That would cause the cylinder not to fire and excess fuel from not burning it up. I'd say it is that or your MAF.

The maf i've seen cause the car to idle perfect, but not rev more then 1500-2000rpm. Normaly the MAF when its toast is toast, not streaky. Gas out the tailpipe(excess carbon) will also result from this.

Check the plugs and you should prolly throw new ones in at that time unless you are confident with your diagnosis of them. Check the insulation on the coilpacks
and make sure no part of the tube on them is ripped or damaged and the plug goes in fine.

Getting the computer codes will be your first most beneficial move.
I say it sounds like you really have a few multiple issues(also a boost leak)but it seems like your issues are ignition related, or electrical related. Make sure none of your wiring harness has gotten ripped or burned(check wires by turbo(exhaust housing.
Just do 1 thing at a time because I can tell you are confused and frustrated and may be making more issues or mistaked for yourself or maybe in what you just wrote above.

Do you still have your tap, stock chip. Try that to see if you can access with VAG-COM
 

440 and 3" maf should run pretty good on standard chip. At least for troubleshooting!

TAP chip is gone, I've got the stock chip...
 

But I'd have to go pay for reinstall, and last time I tried to run on 3" maf and 440s on stock chip, it ran about as smooth as it currently is.

Thx for the good advice, will check it out...
 

but it seems to be more of a fueling issue than an ignition problem in my mind right now.

3" MAF and 310's will run OK on stock chip, 440s are too big.

Do you have the older or newer style VAG-COM cable?
 

I know on mine, the wires on the serial cable would break off. I probably have to re-solder them every 6 months or so (then again, I do have the cable bouncing around in my car pretty much all the time) It would give me Adapter Communication error, or somthing like that. Basically, it can't communicate with the adapter (white box on the older units) so it's not a problem with the car.

It sounds like the spark plugs are fouled out. What type are you running? What are they gapped at?
The ECU will see fouled plugs as a mis-fire. The shaking symptons, then clearing up, are another sign.

It could be a bad MAF, but without a VAG-COM, we're pretty much shooting in the dark here. You could try running with it unplugged, but I'm not sure how well it will run since the NO-MAF map hasn't been changed.

I made the chip a little on the rich side, better rich than lean. It's too bad they couldn't get the socket installed, it would only be a 5-minute swap for you to try another chip.

Still got my number? Feel free to give me a call if you have any question.

Running problems solved, but smaller issues still a problem
 

It was quite clear what was wrong when I got a chance to look at the car in good light today. The intake connections had broken apart, leaving the turbo sucking unmetered air, and the MAF sensor completely in the dark as to how much air the engine was receiving.

So that's a non-issue, it has been remedied, along with figuring out why it happened and fixing that too.

Now, I am still having several problems. I need to retry the VAG-COM stuff, but I don't think anything would have changed.

The boost signal is mystifying me also. I unplugged the line at the FPR and plugged it back in. It was acting normal, then on the drive home it started freezing up again. I only recall it displaying positive boost once in the past few days (.10 bar, and that may have been right after I plugged it back in, but I'm not sure). The car feels about like it used to, though, so I don't think it is a boost leak. Maybe the hose is kinked or cracked somewhere. I'm going to take a look when I get a chance.

Thanks

I would probably have to say new style, since I got it about a year ago...
 

and I don't see any white boxes. Should I just open up the outer coating and see if the wires are still all connected or what?

You could try....
 

but you might want to contact Ross-Tech and see if they have any ideas first.