1gcrazy

So last night I picked up my first UR car. It's a 1994, 163k miles, ALL stock, red and it's in pretty decent shape. Might need paint, we shall see. Anyway, i'll post some pictures of it once I bring it down from Denver. Friend and I picked it up from Glenwood Springs. Apparently some little old lady drove it for "20 years" even though it's only been 19...semantics.

Anyway, it's a turd at this point and can barely make it up a hill without downshifting to around 3000 rpm. Apparently there was some sort of coil replacement in the next town over that fixed the problem but then it started acting up(the same) again and apparently she just called it quits and sold it. So I brought a coil with me and unplugged each injector trying to find the odd one out but my best guess was #5. The furthest one back.

I drove it from Glenwood to Denver and it made it... Just wasn't glorious like it should have been. Now i'm trying to figure out the issue. I dont have it in front of me or i'd start with a comp test, then try and figure out which cylinder is down if one is at all...
Also, the lady prior to me changed the plugs really recently. BKR7E's.
Here are the videos:
Notes: One video my buddy is driving back my B5 S4 and it sounds like the UR has an exhaust...and a 2.7t but it doesn't... :'(
View My Video
View My Video
View My Video
View My Video

UrS4boy

Definitely dropped a cylinder. As to why there are five possibilities:

1. Spark plug is dead, possibly blow out of the head. Happens to those who don't check there plugs for tightness (22 lb-ft).
2. Spark plug boot is dead/gone.
3. Power output stage has dropped a channel.
4. Coil is dead.
5. Injector is dead.

If it was 1 through 4 and you drove any distance with the injector (No. 5?) on the missing cylinder connected, you might have damaged a) the cylinder due to raw fuel going through there wiping the oil off the cylinder walls or b) the catalytic converters because of the extra heat generated by the raw fuel.

Oh well, Noobs gotta learn the hard way I guess.

Check the plugs and I will give you some better hints (too late/early to start that now).

1gcrazy

I actually pulled the plugs to change them prior to leaving and all of them look to have been used. The owner even produced a receipt showing when the plugs were bought. They looked good. I saw the gap was .03 and to eliminate any issues with gap as i've had with my B5 which i've completely rebuilt.......I tapped the plugs down to about .022. When I went to pick the car up, I had a new set of BKR7E's to throw in but since I saw the plugs were new and all looked the same color, I threw them back in.
I'm not worried about the cat since Colorado Springs doesn't have emissions. If it IS the cat, i'd just cut it out since the exhaust is so quiet I can't even hear the motor at idle...
I am, however, a little concerned about the raw fuel issue. I was aware this could be a problem but the car was so damn cheap I decided to take my chances. Worst case I have to rering it. I drove it about 200 miles and really tried taking it easy. Mainly so any unknown issues didn't rear their heads.
I was under the impression that this only happens to NA cars, basically any car without oil squirters... Oil squirts up into the piston splashes on wall, oil ring accumulates and distributes to the rest of the ring. Gas washes it off and starts all over again? I'm betting it's fine.

I did see your FAQ but since I had video's I figured i'd confirm. I'm thinking POS... These come out of any 92-97 v6? IE the 2.8l?

UrS4boy

200 miles with one injector spraying raw fuel into a cylinder with no spark? Yeesh. IF the miss is that bad, you should have pulled the injector connector OFF and left it off. Now you have to pay whatever consequences that will result. (Who knows what that will be)

The V6s used similar POSs for their wasted spark ignition system (one 3 channel POS for 6 cylinders). They can be used as a temporary fix for one of the AAN POSs. Brown and can often be found in wrecking yards for cheap money.

As for POS versus Coil diagnotics, read THIS (click). Watch for the internal hyperlinks it contains for more POS/Coil fix info.

Kapn.K

I just got back from Glenwood, Sunday. How did you find the car if you don't mind me asking?

1gcrazy

Craigslist. Guy was in some legal trouble and the mom have her old car to him to sell.
What year v6's can I pluck those POS's out of

UrS4boy

Say 92-97 C4 A6 (and probably the 93 to 97 B4 Audi 90 and B5 A4s with the 12v V6).

1gcrazy

Just drove the car home today. It's definitely cylinder 5 that's not firing...

So basically it could still be a pos, boot or coil? It doesn't even look erratic, it's just straight not firing at all...

1gcrazy

Just swapped pins 5 to the empty slot on 227 like stated in those AWESOME directions and it runs. About to go for my first AAN test drive. Woot! Thanks hurseboy!

Edit...
This thing is dog **** slow... It's running on all 5 but really, i'm kind of shocked. Boost leak test in the morning.

UrS4boy

I left you a private message on the S2Forum. You might want to read it.

In the meantime, the first thing to check now that you have five cylinders firing is the moisture trap vacuum/boost signal hose connection. If the hose is off or loose, the boost signal does not get to the MAP sensor in the ECU and the ECU does not control the Waste Gate Frequency Valve = you only get spring pressure boost of about 6 psi = dog.

More info by clicking on the labels in this diagram:
http://members.shaw.ca/speedtek/UrS%...ice%20Map.html