Alright. well i just bought a 1998 a4 1.8tqm with 136k miles with a garrett stage 3 turbo with full apr cat back exhaust. the car has been very well maintained up until a few years ago when the guy just let the car sit in his driveway for 3 years. just got the car home. i bought it cheap as a project car and i knew about these problems before hand so i dont want anyone bitching at me saying that i didnt know what i got myself into or anything like that.

So i bought the car from a guy who hasnt driven it in 3 years, the car has just been sitting in his driveway...thats it. So the first thing that is wrong has to do with the the start up, as soon as you start it the car seems like it wants to die and until it warms up, the car does die. But after the car warms up it idles perfectly. Once you rev the engine or put it in gear the rpm's rise and fall and seems like the car is gonna die and stalls out. Now the check engine light is on so im thinking it might be some kind of sensor or something like that.

I probably left somethings out so if i remember or something else comes up ill add to this. But can anyone give me some advice or tell me whats wrong please? thanks guys!

BTW; is anyone is parting out a black a4 1.8t i need a rear driver side passenger door and the front passenger side fender. If you have either send me a price i need the parts asap! thanks again!

 

you should start by changing fluids, oil in crank, oil in transmission, check out the plugs, change gas, clean MAF... that should get you started

 

if the check engine light is on, go get a scan tool and run the codes. coilpacks, spark plugs, air filter, theres probably a lot of stuff that needs to be changed out.

 

scan
the
codes

 

The car sets the check engine light w/ a code to help you diagnose it. So scan it and let it help you figure it out. The problem your describing does sound kind of like a vacume leak though.

 

i havent had the chance to scan the codes or pickup a scanner but anyway heres an up date:

i changed the gas, oil, air filter, i checked the MAF and it seems clean (idk how else to really check it or what to look for , if you guys could tell me that would be helpful), i found a vacuum leak and fixed it (the boost guage showed a difference after fixing the leak), i checked the throttle body and connections to see if anything was loose or dirty and i cleaned it up, i think thats about all i did so far...i havent had the chance to run the codes or take it to someone..just got the car 2 days ago.

After doing all this the car ran better. Here is what is happening still; the check engine light is still on, i think the cold start sensor might be bad because when i start the car it tends to bog out and did right away, after the car warms up it idles between 750-1000 rpm, once i rev the engine between 1000-2000rpm the car runs like **** and dies down to around 500rpm then it catches and goes back to about 750rpm and idles...if it does not catch it dids after releaseing the gas. But once i rev the engine past 2000rpm the car runs and sounds amazing...its only between 1000-2000rpm where the problem lies...also it takes a few times to start before the engine catches and idles safely...sometimes i need to give it gas and start it in order to keep the engine running. It seems like the problem is with the idle and between 1000-2000rpm.

The car is not a full stage 3 tho. the car only has a t28 turbo, full apr exhaust, and stage 3 clutch. its running a stock ecu and injectors, which i plan on changing after i get the car running and some more cash. The car has 136k on it and the turbo and exhaust have been on the car since around 105k and the owner said it ran fine so i dont think not having a stage 3 ecu or injectors could be the problem after running the car without it for about 30,000 miles. But im not sure, thats why im asking you guys for help. im new to audi and a turbo charged car in the 1st place so i appolozie for being a noob to this.

I've checked the entire car tho and i know i really need to run the codes cuz right now this is a complete guess and check project. The car is running alot better since ive done these few little things tho. what i think is wrong is some kind of sensor problem, it might be the cold start, maf, or o2 sensor but i really have no clue right now.

I really appreciate all of your guys help and i hope you guys can give me a little bit more advice from all this info i gave you guys.

Thanks for the help once again and i wish you all a Happy and Safe Thanksgiving!

 

your car is not chipped after the turbo was put in? that could be part of the issue. same with the injectors, u might want to look into those 2. without codes its hard, u need to go do that. could be spark plugs too.

 

Have you checked out the VAG-COM sticky on the general threads? When I got my Audi two months ago I used the list, shot a couple of emails, took the dude a six of Heineken, and he scanned my ride. Does engine codes and also diagnosed abs problem,, etc. Great system to share tech soft/hardware and also meet nuts like ourselves. Good luck!

 

Another idea would be to seafoam the car (use search - ten billion threads on each page about what/how/where to do it) - sitting that long, seafoam (especially in the fuel) would help to break down some of the resins that deposit out of sitting fuel. Also, get some electrical contact cleaner and clean as many electrical connectors as you can find underhood (keep track of them so you don't forget to hook one or two of them back up). Sitting for that long can allow corrosion to develop on the connectors and degrade their signal conduction.

 

spark plugs?? check also the wires on the coil packs, check the ground on engine, after 3 years... corrosion its a problem