[urq] urq Hot Start Issues

[Patrick Carlier]

It's true   it varies the pressure with engine load . 
a sudden increase of engine load , like full throttle , will cause fuel 
pressure to drop , allowing the metering plate to go higher and thus 
enrichen the mixture . Much like an acceleration pump on carburettor . 

But that's not the main function . 
It's real designation is warm up regulator . 
It's holds the pressure relatively low , causing the engine to run rich at warmup 
and as it warms up pressure rises wich results in a leaner mixture . 
It's also electricly heated to keep warm up time within a certain limit . 

A faulty warmup regulator could very well cause a hot start issue by floating the engine . 
It's easily cheked by monitoring the pressure . 
>From memory , the pressure should rise from about 2 bar on a cold engine to 4.1bar  when fully warmed up .
And it will also respond to pressure variations , wich can be checked by unplugging the vacuum hose . 
I use a syringe to simulate pressure variations .  


Hope this helps 
Pat 





----- Original Message ----- 
From: "Ken LiPani" <mentosman42 at gmail.com>
To: <urq at audifans.com>
Sent: Tuesday, February 18, 2014 9:59 PM
Subject: [urq] urq Hot Start Issues


>I had similar problems when I purchased my URQ. Was waiting for a ferry
> after picking it up and as soon as the ferry arrived I went to start the
> car(after sitting for 10 mins) and it just cranked and didnt even sputter.
> After cranking it for a bit I was smelling the exhaust and didnt smell much
> fuel so I was thinking the fuel pump died or the fuel gauge is wrong and I
> ran it out of gas. Walked down the street and got a can and some gas from a
> station and put it in the car and the gauge went up a bit so I knew the
> gauge was good then went to start it and she fired right up. Made sure to
> keep her running all the way home.
> 
> As for what solved the problem, it was some combination of replacing the
> fuel lines, getting new injectors, new fuel accumulator, pulling
> apart/cleaning the fuel distributor, and replacing the pressure regulator
> on the side of the block(the thing with the two fuel lines going to it).
> 
> That pressure regulator is supposed to vary the fuel pressure depending on
> the vac/boost it sees(if I am remembering this correctly) so if you had a
> fuel pressure tester setup(basic CIS test kit) you could hook it up in line
> and rev the engine to different vac/boost levels and see what pressure you
> are getting out. Mine wasnt varying the pressure at all so I replaced
> it(there is a guy that actually rebuilds these).
> 
> 
> Hope this is some help.
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