Engine stopped groaning. Idles Much Smoother.

[Fourkguy@aol.com]

FWIW - ended a frustrating investigation into a problem which has been driving
me crazy.

Appx 3 mos. ago I let my mechanic tune my 86 4KS so I could see the potential
(as a benchmark for what I could achieve in future tune-ups.) Car ran nice,
much smoother than before & I was happy. After a while I started noticing an
unpleasant engine sound at appx 3000 RPM. Also idle was not smooth and got
some hesitation at low speed clutching, especially off the line & parking. At
the advice of the list, used a can of Techron, changed to Mobil 1 and sound
was not really noticeable to me. Started buying lower octane fuel as it was
much cheaper here at the advice of some listers. Some time later, the sound
reappeared also at 3000 RPM. Attributed this to the fuel octane & started
using super only. Also added can of Techron to remove whatever deposits I felt
the low octane fuel donated to me. Also ran a few Italian Tune-ups (the list
has expanded my vocab today) looking in my rear view mirror and scanning left
& right nervously. Well, all this did was change the sound, & move it to appx
4000 RPM.

Been meaning to check spark plug condition for a while now, but didn't have a
socket that fit the Bosch Super plugs that my mechanic installed. Today I
bought the socket and checked the plugs. What I found was the three electrode
kind of plugs in cyl 2 & 3 were evenly gapped and deposits were gray and even.
Looked pretty healthy. Cyls 1 & 4, however, had two well gapped electrodes
which looked fine and one with a much smaller gap which had dark, unhealthy
looking deposits. Re-gapped & cleaned them and THE CAR RUNS GREAT. Idle is
smooth. Hesitation gone. Was ready to check ISV, but the investigation is
over.

Thanks to all for the unbelievably helpful advice. I LOVE THIS LIST!

Jeff