Performance Problems -- 1984 4ks 1.8L

b1biker b1biker at
Tue Nov 6 20:33:30 EST 2001

I have had performance problems with my 84 4KS since early August. At that
time I replaced the power mirror on the drivers side with one from a VW
Quantum. In the process of re-wiring the plug I caused a short which blew
the fuse for the power mirror circuit. When I went to start the car it would
start, idle for a few seconds and then die. This could be repeated over and
over. Prior to changing the mirror the car ran fine; although it did use
some oil, bad stem seals on #3 cyclinder. After much fruitless diagnostic
work on the CIS I took the car to my friendly mechanic. He discovered the
rotor/cap to be bad. These were replaced but the car still would not run
properly. It had difficulty in coming off idle and would not rev above 3k;
it only reached that rpm with significant hesitation. The mechanic told me
that he thought the problem was in the CIS and did not feel that it was an
ignition problem. Since that time I have replaced the fuel pressure
regulator and adjusted the position of the mass airflow sensor plate. Both
of these improved the operation of the car but it still hesitated coming off
idle and sputtered throughout acceleration up to about 4k rpm. I finally
cxheckedc the plugs and found them carbon fouled. After cleaning the car now
starts and idles fine, it accelerates well up to about 60mph, 4k in 4th
gear. As I accelerate I seem to hear a sucking noise from the engine
compartment but can not find a vacuum leak. The car has little or no power
at 4k rpm and will not accelerate or even maintain speed in 5th gear. It
also runs with the temp guage right at the top of the normal range; it used
to run about 3/4 up into the normal range. I have not replaced the fuel
filters but will be doing so in the near future.

Questions: 1- Is it possible that the fuel pump is simply not delivering
sufficient fuel?
2 - Is it possible that the over-rich condition that fouled the plugs before
I replaced the cap and rotor caused the catalytic converter to become
What have I overlooked? Any advice/suggestions would be greatly appreciated.

Gary Meier
84 KS, 83 CGT, 88 5KSQ

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