no start 90 200 qw

["Scott Mo." <scottmo@teleport.com>]

>Dave wrote:
>idle speed and co setting both needed adjustment - the freq valve was
cycling 
>down to 100% duty cycle every 10 to 15 seconds. I reset every thing, and
then it >idled fine.

If you saw a very high duty cycle at the freq valve, this is indicative of
a vacuum leak in the system. You should never have to adjust the mixture
that much from the original adjustment with a  correctly sealed
intake/breather system.

This assumes the adjustment was not fooled with by someone else and the
fuel distributor plunger movement is smooth and it is not sticking.

Have you checked the following:
replaced the fuel injector inserts and o-rings? 
checked the back side of the main breather hose?
check underneath the  rubber Tee fitting at the valve cover?
checked the breather hose from intake boot to valve cover tee fitting?
Replaced the valve cover gasket?
Accordion hose at intercooler?
Intake pipe rubber connection at Turbo?
Turbo exit hose?
Idle Stabilizer valve hoses blown off slightly?
Dipstick and oil cap gasket?
Sticking Decel valve behind r/fender (pretty rare)
Cam or Rear main seals? (less likely)

One other thing, did you pull the cold start valve and watch it spray into
a bottle during the output test? If you had the gauges connected, you could
also watch for a pressure drop when the cold start valve is briefly
actuated with jumper leads.

My 89 200TQ would not start the other day in 20F weather,  I had to jumper
the cold start valve to get it to fire up. I was using a spare ECU that had
a dead transistor for the cold start valve circuit. The ECU output test
confirmed it was not getting grounded by the ECU. I am embarrassed to say I
have been driving it around this way for several months!  It always started
when the temps were above 40F.

HTH
Scott Mockry

http://www.teleport.com/~scottmo