'85 4kq no start, no fuel to injectors - the answer!

Ben Swann bswann at worldnet.att.net
Wed Jul 31 18:50:05 EDT 2002

And the skillfull (or was he lucky?) winner of "what is wrong with my
engine?" is  Martin Pajak who got the correct answer first..

> >Another Hint:  The defective part has electical control, althought the
> >fix was not electrical.
And On Wednesday, July 31, 2002 1:28 PM, Martin Pajak
[SMTP:Martin at quattro.ca] responded:
> Differential Pressure Regulator on the side of the FI distributor?
> Cheers
> Martin Pajak
> http://www.quattro.ca
> 1983 Audi Ur-quattro (269,000 km) Canadian spec. winter car
> 1985 Audi Ur-quattro (156,000 km) Euro spec. import ;o)
And Huw came in a close second...

Duh, my turn?  Control pressure actuator screen totally clogged?
Huw Powell



Which was very close and sufficed to answer the question.

And Elliott Bavely was very close -"it turned out to be the plunger in the
fuel distributor that sits above the other end of the air sensor plate
"lever".  In my case, the plunger had a bunch of crap (fuel that had turned
into varnish after sitting for a few years)  on it and was stuck in its

and that would have been my next place to look, or as he did just
substitute out fuel distributors, which I'm glad I didn't have to.

Here is a description of the problem and fix:

Basically the Differential Pressure Regulator became so blocked that no
fuel would pass through into the metering head.  After referring to
troubleshooting section in Bentley wherby it referenced Differential
Pressure several times under the symptoms I seemed to be having, I then
unscrewed the Diff. Pressure Reg. from the fuel distributor.  I had never
seen such filth.

I carefully removed the O-rings which will be replaced with 034133487, and
cleaned them up in order to reuse temporarily.  I actuated the fuel pump
momentarily to shoot out any residual debris using a towel to catch -
thrown outside immediatlely.

Then I cleaned up the gunked up pieces and shot carb cleaner through 'til
everything was pretty.

Reassembled.  Actuated fuel pump to charge system.

In a few cranks it fired, but I had to make some serious adjustments to the
mixture which had been  out due to PO tampering to compensate for all of
the leaky vac. hoses and probably this problem which coincidentally killed
the car just after I got it.  That seems to be my luck.

Thanks for playing "what is wrong with my engine?"  Hopefully the next
round won't be one of mine.

With 8 (or is it 9?) Audis in the driveway now - several 4kq's and a coupe
for sale.

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