re. 4KQ runs rough when cold...

[Swann, Benjamin R. (BSWANN)]

Bill,

I experience(d) the same thing.  After giving everything obvious a good
going over, incl. plugs, cap rotor, fuel filter, new fuel pump, air filter,
all vac. lines tight, replace injectors, cold injector not leaking, etc. I
still had the problem. 

I was able to virtually eliminate the problem by cleaning the fuel pressure
regulator located on the side of the fuel distributor.  Carefully take this
off and give a good cleaning with gumout/other.  There are two O-rings you
may want to replace.  I had to do the procedure twice, as the first time I
put it back on, there was no pressure to the injectors, and the car didn't
start, as something must have dislodged and blocked it during cleaning,
or???

Now the car still has a slight problem, which returned after several months,
but only on very cold days, when just starting.  Before the cleaning, I had
tried everything else I could think of, but the car would run like crap for
the first minute or so of driving, even in warm weather.  I found the
problem to be similar to the mechanical fuel pressure symptoms I'd had in
CIS cars, and thought to give it a try, with the Bently pointing me in that
direction too.

Give it a shot (of carburator cleaner).

Ben
'85 4KCSQ - project GTQ

<I've notice recently that after starting my 87 4KCSQ in the cold weather,
it
runs a bit rough for the first minute or so. The car starts fine and idles
fine, but if you press the accelerator too soon it chugs a bit. Once it
warms up, the car runs great. >