4kq hard starting-stumbling

Bob D bob at audisport.com
Wed Jun 22 18:58:55 EDT 2005

Have you checked the DPR? Also hows the motion of the CIS plate? These 
two items have given me problems in the past...

Huw Powell wrote:

>> I've been having a problem w/ my '85 4kq lately that I
>> can't seem to figure out.
>> Problem:  Hard starting when "cold"-- cold varying
>> from 50F to 95F.  Car will sometimes catch when key is
>> first turned, but then stalls.  After a few attempts
>> the car will eventually start, but will have trouble
>> idling for about 30 seconds- usually need to keep the
>> revs above 1500RPM during this time - then the idle
>> evens out and I can drive away.  Once car is warm, I
>> can turn off and restart easily.  AFter it sits for a
>> few hours, the hard starting begins again.
>> Diagnostics/Changes so far:
>> -Swapped ECU temp sensor with known good--no change
> Darn, that would have been my first guess...
>> -Checked after start enrichment function--ECU does
>> enrich mixture after starting
> You're checking it by observing the current at the control pressure 
> actuator, right?  One thing you could try would be to remove the CPA 
> and shoot some brake or carb cleaner through it both ways.  They do 
> sometimes get clogged.  Be careful not to lose the two small o-rings.

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