Re: 87 4KCSQ question

[Luis Marques <marques@ti.com>]

Dave Kodis <dkodis@earthlink.net> wrote:
> I have a problem with my 87 4KCSQ........
> When it's cold, late fall 'til spring, I have to let the car warm
> up for 7-10 min. or it dies out to idle when I gas it. It can get
> up to between 2500-3500 revs. then hits a dead spot and I 
> have to let it go back down to 750.  After the car warms up, 
> I don't get the problem any more.  Someone mentioned it
> may be the throttle microswitch??  I like to be sure because
> at US $126 I'd hate to have to guess wrong...   

Huw Powell responded:
> Sounds like a bad/faulty warm up regulator symptom - you're too lean 
> until the engine is warm.  Might not be, though.  Do you have access 
> to fuel  pressure gauges?

The later 4kq's didn't have a warm-up regulator.  They have the CIS-E
F.I. system that controls the mixture electronically.  It could be the
coolant temp. sensor/wiring that is bad.  It signals the computer to
enrich the mixture for better driveability when the engine is cold.  Of
course, you must also check your spark plugs/wires, distributor cap &
rotor, etc. to make sure they are providing a good spark.  I don't see
how a bad throttle switch could cause your problem, but it can be
checked easyly with a multimeter.

Hope this helps.

Luis Marques
'87 4kcsq