a4 b5 no power, stutter, who can solve this mystery
 

Hello all, first Audi, first post, please be gentle

So heres the deal, bought a 1999 a4 2.8 with a stutter but I can't seem to figure out what is going on with it.
heres what I know:
I changed the fuel filter, old one very clogged
injectors all spitting
plugs all firing, based on pulling them one by one and noticing a change in the engine, note there was some oil in the number 4 hole under the oil cap but the plug seems to still be firing
cleaned the maf, that seemed to have helped a little bit
the vacuum hose that goes across the front of the engine that always rots and breaks was rotten and gone, the end had some crud in it, replaced that
there was an exhaust leak in front of the driver side cat where the cat joins the header, someone replaced that joint and used jb weld to seal it and it had rotted away, i re-jb welded it and it is quieter now
the air filter is clean
I tried pulling the plug to the maf because i saw somewhere that doing that might just delete it and make the car run on presets but when i pull the plug the car shuts off
where I am at now:
the car will start and idle but when any gas is applied it shuts right off
the check engine light is on (not blinking) but when I hook up the code reader it just says error
I have a can of bg44k ready to go in
I have no idea what vag com is
I was going to clean the throttle body but some research indicates that they rarely have problems
now im thinking it may be the coil pack and or icm
should i reset the engine computer by disconnecting the battery and touching the wires together? would that help the code reader pull a code?
Should I pull the valve covers and see if it looks terrible inside?
Im pretty lost and would appreciate any help. Thanks guys!

another thing is someone told me they thought i had a clogged cat but i was able to push a piece of threaded rod all the way through the drivers side one, havent checked the other side

Gonna need to find a way to see the codes. What code reader are you using? Any cheap one should be able to pull codes but it sounds like yours, for whatever reason, is not.
Can you borrow somebody elses? Or rent one at an auto-parts store?
Most anybody who works on cars even occasionally will have one. Hell I pointlessly have two.

Other than that...
Vacuum leak? MAF? Throttle body WAY out of alignment? Fuel pump? o2 sensor?

update
 

thanks for the input, im pretty sure the fuel pump is in good shape because when i replaced the fuel filter i lost the sealing washer at one of the connections and it was spraying out like crazy so it seems like it has good pressure. I did the throttle body realignment procedure, that didnt seem to make a difference. The code reader i have is a cheap inova one, idk why the heck its showing error its obdII it should work.

update
 

i suspect that the code reader is not working because the radio is not hooked up. the previous owner had a dvd player in there and the wiring is absolutely butchered. Is there an easy way to just jump the wires without the radio installed so i can get a reading?

Yikes. You may need to find somebody that can look in there and see which wires go where. It's hard to say without seeing them.
Is the dvd player gone now? Or can you start the car up (not just 'run') to see if full power will give it the info it needs?
And just for the sake of it, can you try the code reader on another car to be sure it's not THAT that's the issue.

Is the ABS light on, if so the controller has probably failed (they all do eventually) and that can cause comm failures that prevent code readers from working properly. If the light is on unplug the connector on the top of the ABS pump/valve body and see if you can read the codes.

update
 

The ABS light is on, sorry I should have mentioned that initially. I unplugged the controller and tried the code reader, still error. I briefly tried to rewire the radio last night but the wire pieces are just too short to work with. I think my next move will be to buy the radio wire harness used and splice it in.
Also I cleaned the oil out of the number 4 plug well by washing it into the chamber with some carb cleaner and no more seems to be leaking in, the engine is idling very smoothly now but when I try to apply gas is shuts off immediately

update codes!
 

I got the code reader to work. The only reason I can think of that it may have suddenly worked is that I had the battery unhooked overnight cause I was working on the radio wiring, I really dont know. But.. here they are
1237
1238
1239
1240
1241
1242 These are for cyclinders 1-6 saying there is an open circuit for the injector I think?
1545 throttle position control
0302 cyl 2 misfire
0102 Maf input too low
Hope this helps!

okay lets look at each one

p1237
p1238
p1239
p1240
p1241
p1242
p1545
p0302
p0102

It appears you are correct, p1237-p1242 are open circuits for each injector.

p1545 says something's messed with the throttle body. Dirty, broken, etc.

p0302 is the misfire. No surprise there given the injector and TB issues. You can ignore that for now since we're assuming it's a sub-issue of the other one. Only surprise is that you don't have errors for all 6.

p0102 is the MAF input because you unplugged it. So okay to ignore that one too.


First thing to do would be to check some fuses: 28, 29, 32, and 34.

http://i955.photobucket.com/albums/a...A4FuseBox1.jpg

Curious about your throttle body too. That would cause the idling/dying. Can you take the intake snorkel off to wipe it off/clean it? Assuming you have some spare hose clamps. Just be VERY careful. I cleaned my TB but in doing so I dropped something into my transmission and ended up having to pay ~$1500. Don't let ANYTHING drop. There's a small hole just below the TB that drops directly into the bell housing. Put a rag or something there to cover it.... seriously.