Re: 4500 RPM cutout

[steveb@falcon.kla.com (Steven Buchholz)]

>   Can anyone put me on the quick track for checking the common gremlins
> that cause the TQC (and maybe 5000TQ) to cut out at 4-4500 RPM.  I know
> there are some ground checks involved, but knowing which ones will sure cut
> down on needless hunting. 

I've never had a 4k cutout on the 5000, but I've definitely experienced it 
on the QTC!  My first recommendation is to clean up the grounds.  IME, the 
one that is attached to the back of the intake manifold is most important, 
but I also cleaned up the braid that connects the block to the frame and 
the several body mounted ground points in the engine compartment.  Another 
possibility is that the distributor is not lined up properly.  You may also 
be having a problem with overboost.  

... just so happens I've got my quattro maintenance & adjustments books here. 
ther sources: defective air temp sensor (mounted on the intake manifold) 
[should be 13-33 ohms as measured at pins 18 and 19 of the F/TCU connector 
BTW].  If fuel pump shuts off @ 4500 RPM check: air temp sensor (mentioned 
already), Idles switch, boost pressure, frequency valve and wiring.

HTH!
Steve Buchholz
s_buchho@kla.com
San Jose, CA (USA)