4kq runs poorly when warm

Brendan K. Walsh bkwalsh4201 at hotmail.com
Wed May 12 08:23:36 EDT 2004


How about the temp sender for the csv(back of the head)? Csv stays on=crappy
running when hot. Though i think they usually break the other way round, ie,
no cold start...

Brendan

"If God had intended us to walk he wouldn't have invented roller skates."
Gene Wilder, Willy Wonka and The Chocolate Factory.
----- Original Message -----
From: "Huw Powell" <audi at humanspeakers.com>
To: "chris hart" <chrishart13 at yahoo.com>
Cc: <quattro at audifans.com>
Sent: Wednesday, May 12, 2004 4:34 AM
Subject: Re: 4kq runs poorly when warm


>
> > Always starts right up and idles smoothly at
> > 1000-1200rpm.
>
> Ooh, ooh, can I bring back the buzzer?  Ok, no...
>
> That's the first thing wrong.  The car is supposed to idle at about
> 800-850 rpms.  So, something is wrong with your CIS.  I suspect
> maladjustment to correct for something "else," or a sticky/dead ISV.
>
> > Runs very strong until it's warmed
> > up(even better when the ambient temp is low) then
> > throttle response gets sluggish and it feels half dead
> > and won't wind out in first and second but clears up
> > by third to run pretty strong but still off.If it's
> > very hot outside it'll sputter approaching
> > redline,too.I've recently replaced the timing
> > belt/water pump,cap,rotor,plugs,every vacuum line I
> > could find,and the air filter.All the hoses involved
> > with the CIS are good.From what I could tell with my
> > cheap,analog multitester the coil is in spec,but I
> > suspect it anyway;I think I've heard of heat related
> > intermittant coil issues.Or maybe a sticking
> > centrifugal advance(but that wouldn't be effected by
> > heat)?Any ideas?
>
> Maybe the temp sender for the CIS, but I doubt it.  As I said, it just
> might be adjusted wrong (perhaps for bad hoses that you replaced?), but
> I think it's more than that.
>
> It runs strong cold - so it's nice and rich.  Maybe too rich.  But if it
> was so rich it couldn't adapt when warm, it probably wouldn't run ok
> cold.  Still... how about measuring the OXS voltage (while connected)
> after it gets warm and is idling?
>
> It couldn't hurt to clean the ISV with carb cleaner and learn to measure
> the DPR current so you can adjust the static (idle) mixture.
>
> Someone mentioned plug wires, couldn't hurt to take a close look at
> them, too.
>
> --
> Huw Powell
>
> http://www.humanspeakers.com/audi
>
> http://www.humanthoughts.org/
>
>


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