# 2.0 aba, 8v BV head running lean at high rpm CIS BASIC



## rallymk1 (Oct 17, 2005)

Having issues troubleshooting a lean condition above 5K... 
2.0 ABA w/ 8v solid lifter head 
running CIS BASIC 
thin-wall air plate, BMW 320i fuel dist, new mercedes brass injectors 
audi 5000 (or something) large throttle body 
full P&P and properly rebuilt head, TT 288 cam 
WUR removed from block 
Runs on a 50/50 mix of Sunoco 260GT Plus (104) and super 

Car was running fine until 2nd day of last event when it started going lean and dropping power above 5K at WOT, mixture is right where it needs to be on wideband until 5K then it drops significantly.(I don't have exact #'s) 

Guy working on it is thinking possibly an issue with fuel distributer, any other ideas? 

Running out of time as next event is about a week away! 

Thanks for any input or thoughts. 
Jv


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## jaredtrobinson (Sep 4, 2010)

I am but a nub ... however, I know that VW put a full throttle enrichment switch on the JH engine. As to what has changed? I haven't a clue  GL though


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## bubba_vw (Dec 3, 2008)

have u checked the pumps?


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## rallymk1 (Oct 17, 2005)

that was a thought of mine also... 
we have checked fuel pressure which is okay, but not the pumps specifically 
mechanic dude says fuel pressure or delivery issue would cause a problem through the whole range not just at high rpm...I'm not so sure...but he's the expert


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## bubba_vw (Dec 3, 2008)

does it make a difference if its the first run or after a few runs?


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## rallymk1 (Oct 17, 2005)

I have never tested it cold but it's in a rally car so doesn't get driven much. When it started doing this it was on the second day of an event after running great for 6+ hours the first day, it started pretty much first stage of the second day and ran like this for 6+ hours that day. I did an all day drive in it a couple months ago and it was doing it pretty much whenever the situation described (>5K @ WOT).
Is that the info you're looking for?
Thanks!


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## ny_fam (Apr 3, 2004)

Sounds like a air leak happening at high vibration or high load when engine tilts/moves, or loose connector on the frequency valve. Both or each could have happened after your 6+ hour run.


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## dogzila22 (Apr 1, 2008)

use audi 5000 wur, don't lean at top end


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