Fwd: '88 5K cold start problem

["Eric Renneisen" <renneie@hlthsrc.com>]

Forwarding a plea for help that came in through the web site. 
Please contact Peter directly. Thanks.

>>> "Peter Matamala" <p_matamala@hotmail.com> 12/23/98 03:30pm >>>
Hello,

I would like to thank you for taking the time to post such a helpful
and 
informative website.  I am the owner of an 1988 5000s and find that
the 
20v and my car share many of the same ills.  

I am experiancing a cold-start problem.  In fact, I have been a
scholar 
of this problem for about 1 year.  I would love to take it to the 
mechanic, but my student budget does not allow for this. I'll describe

the problem to the best of my ability, any suggestions you could offer

would be greatly appreciated.

The car starts,and runs fine for about 1 minute.  It then starts to
get 
erratic in idle and eventually stall.  The problem is worsened if I 
press the gas pedal during this time (I can sometimes prevent stalling

by not pressing the pedal while starting, despite the owners manual 
suggesting one do so)  Once it has stalled, I will restart it at which

time it will run for <10 secs.  In order to keep it running I must 
depress the gas and rev the engine to at least 2000 rpms until it has 
warmed up sufficiently.  While I am pressing the gas, the engine will 
hesitate, or sort of skip a beat every few seconds.  I hear the noise
of 
a relay in the passenger footwell actuating while this is occuring.
This 
only occurs in temps less than 40 farenheit.

I have tested the ISV as you suggested, and pulled the harness on the 
thermotime switch to test the function of the cold start valve. Both
are 
O.K. I have also replaced the multifunction temperature switch.  This 
was peculiar because the aftermarket switch has 3 connectors, as
opposed 
to four on the original.  The aftermarket has no terminal for 12
volts!  
I was able to get a reading on the terminals concering the temp gauge,

but the other  two, when tested for resistance, gave a reading of O.L.

on the multimeter.  Is this possible?  Is my new multifunction switch 
faulty, thus causing ECU difficulty and hence cold start trouble?

It has been suggested that my problems could be caused by a faulty 
differential pressure regulator on the fuel injector, or possibly a
bad 
fifth injector.  How would I test these? Any other suggestions?  
Anything you can offer would be helpful. 

Thank you, 

Peter Matamala
 
p_matamala@hotmail.com
Matamalp@clarkson.edu