[urq] Starting and running after hot start

[Mike Sylvester]

As with most CIS running problems...vacuum leak.

When cold, CIS will fire the cold start injector and a car with a vacuum
leak will start OK.
Once warm, the cold start injector does not squirt and a vacuum leak can
keep the throttle plate from rising.

Mike

www.urq20v.com

> -------- Original Message --------
> Subject: Re: [urq] Starting and running after hot start
> From: "urq" <urq at pacbell.net>
> Date: Mon, September 14, 2009 12:34 pm
> To: <urq at audifans.com>
> 
> 
> Agree.  There is so much information to be gained by reading the fuel system
> pressures ... 
> 
> One other thing to check on a MAC-02 is functionality of the OXS Freq Valve
> .... I found my car's Jekyll/Hyde nature was due to an intermittent drive
> signal to the OXS Freq Valve ... the valve buzzing should be easily heard
> when it is running.  From my BTDT it seems that the function or lack of
> function is far more critical in warm start conditions.  
> 
> Steve Buchholz
> 
> -----Original Message-----
> 
> Not to nit-pick - but I would consider that a "warm" start problem.  Back
> when I had CIS (6 yrs!!) - my car had a warm start problem. It would start
> right up no problem after sitting for a few minutes (hot start) but give it
> a half hour and it would start hard, idle rough.
> 
> My memory is fuzzy but here are my thoughts:  
> 
> Check your fuel pressures - might need to rebuild the plunger/o-ring set in
> the fuel distributor.
> Fuel check valve (can't remember if this is in the accumulator or pump)
> Fuel accumulator
> Leaky injectors?
> Injector fan working? - does it have the hole cut out to send air to the
> fuel lines?
> 
> Don't forget to pressure test for vacuum/boost leaks.  #1 cause of problems
> IMO. 
> 
> Brandon
> '84 ur
> 
> -----Original Message-----
> 
> Hi everyone.  
> 
> My 83 URQ has developed a "hot startint" problem lately.  Cold starts are
> fine.  However, when I get to my destination, park the car for an hour or
> two, come out start it, it starts, but it will not run (idle).  I can keep
> it going (heal and toe type thing). But the other day I stalled at an
> intersection, so I had to wait for about 15 to 20 minutes before it would
> star again.  I managed to get it home, but before I turned off, I checked to
> see if it would idle.  It did as it normally does.  I thinking perhaps a
> couple of leaking injectors??  Would appreciate any input from anyone. 
> Thanks in advance.
> 
> Tony:  88 Audi Q 90, 1983 URQ, 2008 A3 S-line.
> 
> 
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