[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: Ur-q fuel system troubles

OHOE wrote:
> Hi, I posted about this a couple of days ago but got no responses so I thought
> I'd try again with some new information. My Urq is running very lean. It

how do you know it's lean? There are many reasons for starting problems
and untill you take the pressure readings (system,control,residual you won't
have a place to begin t/shooting.
> doesn't like to start very much when it's cold and really doesn't start very
> much when it's hot.

Cold start injector not working will give hard "cold starts" if it works 
all the time (when the engine is warm) you can have a hard "warm" starting condition.
Loss of residual pressure will also give hard starts.

Poor injector spray = hard starts.

 Power is also greatly diminished, although at certain
> times the power comes back for a little while and then goes away again.

Fluctuating fuel pressure will cause this.Hook up a gauge and 
read the pressure,see if the needle reads steady.

Since the o2 sensor signals the computer to regulate fuel delivery via duty
cycle.You have to check the duty cycle.Can you hear the freq. valve cycleing?

Check for vacuum leaks.The controls can compensate for minor leaks but once they become 
larger it reaches it's limit of control.
> does this sound like? System or differential pressure regulators?The cis system in the urQ doesn't use a differential pressure regulator.Cis-e
 need to know the pressure readings and delivery volume to eliminate the pump.
> valve? need to know the residual reading and time it holds res.pressure.

 Distributor? Not likely,but possible.You must determine if the fuel system 
  is the culprit before going off on another tangent.

  Without systematically doing the tests (as described in Probst) narrowing the
  field of "what could be wrong" would just be hit/miss.Sorry,but that's the
  best advice I can offer.
  Replacing parts that might be bad is very hard on the wallet.

  Given a place to start,I am sure the wisdom of the list will prevail and have
  you smiling in no time.


 I'd really appreciate any help, and soon, please. I'm
> supposed to be taking the car somewhere a good distance away tonight:(!
> Private responses would be best as they get here faster than the digest.
> Thanks so much (fingers crossed),
> Oliver
> 83 urq
> 84 gti
> 85 16v gti rally car