[urq] stumbling under boost

[DGraber460 at aol.com]

In a message dated 6/6/2008 8:03:35 P.M. Mountain Daylight Time,  
a.sigal at bluewin.ch writes:

My 85  urq runs great, except it has developed a nasty
>stumble at full  throttle and full boost.
>
>Can't find a vacuum leak and duty  cycle readings seem
>to be correct.



Sounds like classic boost leak. Turbo over-boosts due to lack of  resistance, 
and ECU shuts off the fuel pump.
If you don't have one make a pressure tester out of ABS pipe and a cap  glued 
together and clamped into the turbo intake. Drill, tap, and install an air  
fitting into this "plug". With this you can pressurize the system and with a  
stethescope check for pressure leaks. Careful not to pressurize more than ~  
10-12 psi or you risk blowing your pressure transducer in the ICU. To be ultra  
safe, isolate the ICU "just in case".
Bet you a beer you find a leak (or 2). Even small leaks that vacuum  will not 
betray will be quite obvious.
Come out in August and I'll either collect or pay up!
 
Dennis
Denver



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