# 1990 AUDI V8 NEED HELP NOWWWWWWWWWW!!!!!!!!!!!!!



## congratulati0ns (Jun 29, 2007)

Im only 17 and i love audi and just got a 1990 Audi v8 with the 3.6L v8 and im planning on working on it with my dad, startiing with some mechanical issues. 
1. The engine starts and runs, and when your driving or revving it, it hesitates, you cant just step on it from 40mph lets say and get it to 70-80mph quickly you have to so very slowly on the throttle, same when stopped and revving, doesnt let me rev past 3,500-4,000 with out bogging out, i would have to go slowly on the throttle to get it past 3,500-4000rpm. If you have any suggestions what is causing this, email me at [email protected]
2. The second issues is that the CAT light is flashing, what should i check or replace first? O2 sensor or CAT's? 
3. The Antilock cant be turned on, the light is anlways on "Antilock Off" no matter how many times u press it to go on.
Thanks 
-Matt


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## MikkiJayne (Jan 1, 2007)

*Re: 1990 AUDI V8 NEED HELP NOWWWWWWWWWW!!!!!!!!!!!!! (im2fast4u16)*

I think 1 and 2 may be related. The cat light comes on when the cat is overheating, and that is most likely caused by a fuelling problem - probably running very lean from your description. There is a sensor in the back of the drivers side cat which goes up in to the floor.
I'm fairly new to this engine myself, but the first thing I'd do is pull the plugs and have a look to see if any of them look different. That may show up if its a problem on a particular cylinder or not. Then maybe check the FPR, filter, pump, etc. It could be that the fuel pressure is low?
The ABS light staying on indicates a fault in the system somewhere, most likely a sensor. You'll need VAG-COM for this (with the dual K-line connector option) so you can check what the electronics are saying. This may also help with diagnosing the engine problem.
Good luck http://****************.com/smile/emthup.gif 
Mikki x


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## srvfan84 (Jun 23, 2006)

*Re: 1990 AUDI V8 NEED HELP NOWWWWWWWWWW!!!!!!!!!!!!! (MikkiJayne)*

My strongest guess is a vacuum leak. Look for a crack in your intake boot. This would make you run really lean, causing it to both bog down and create higher temperatures in your head and exhaust. Look for any entry of unmetered air. 
This may definitely make more sense if you notice it gets worse when it gets warmer.
One way to test for leaks is to let your engine warm up and spray carb cleaner on suspected areas. If there is a leak it will raise your idle. Again, I'd start with the intake boot.


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