1975 C10 350 2bbl missing when cold

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BT3 - 02 Feb 2006 14:12 GMT

Missing on a couple of cylinders when engine is cold and choke is set.
Lasts for about 1 minute or so, then starts firing all cylinders and resumes
normal cold idle. Continues to run properly after it's warm. Problem
started the morning after the timing correction, but I've verified that it
is correct.

Background:
NEW plugs gapped to .060, plug wires, HEI Ignition control module, HEI
rotor, HEI coil, distributor housing, PCV valve, rebreather filter, air
filter, fuel filters
Adjusted timing to 6BTDC @ 600RPM in Park, readjusted idle to 600RPM in
Drive

Other:
Mechanic says .060 is too much gap for HEI, as resistance is too great. Book
and truck stickers say .060
Valve cover cleaning and gasket replacemenet scheduled this weekend. Noticed
there is significant oil "baked" on rickers, etc inside the cover. Will
plan on running a can of detergent through before this. Could there be any
relationship to the miss now that the timing and idle are correct?

Thanks, BT3

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Whitelightning - 02 Feb 2006 22:02 GMT

> Missing on a couple of cylinders when engine is cold and choke is set.
> Lasts for about 1 minute or so, then starts firing all cylinders and resumes
[quoted text clipped - 8 lines]
> Adjusted timing to 6BTDC @ 600RPM in Park, readjusted idle to 600RPM in
> Drive

.060 for gap is perfect , and the timing is right, but if the chain is
stretched, could
be causing a problem, what was it before you moved the distrib?
which plugs did you install?
AC Delco should be R44TX.
There is also an R44T, that should not be used.
the X stands for wide gap HEI ignition.
The T for tapered seat.
there is also an R44TS that should not be used , the S
indicates moderate extended reach 7/8 inch long and was used on the
'76 and later
Bosch plugs and GM HEI are a marriage made in hell

http://www.acdelco.com/html/pi_plugs_ident.htm gives a nice break down
of AC plug
codes.
Is the choke pull off working correctly?
Is the choke set correctly? the unloader measurement is 0.275 measured
between horn
top of choke butterfly, adjust by bending tang on fast idle cam

Whitelightning

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BT3 - 03 Feb 2006 00:58 GMT

The timing WAS 11 BTDC. As mentioned I moved it to 6. Perhaps I'll need to
draw a happy medium.

Admittedly, I used the cheapest plugs since I knew I was only going to leave
them in there until this weekend, then put in AC's. That might be my
trouble. When I got them, they were gapped at .025. When I gapped them to
.060, they just looked strange, pointing out almost.

The choke seems to be operating correctly. It WAS having some trouble when
I got it, but I cleaned the exterior linkages, then lubricated them and
everything actuates correctly. As far as specifics, don't know. My
chiltons says "We'll just assume your carb is working OK, moving on ...". I
would need the "Carb adjustments for Idiots" book, as it's always been my
understanding that these things work on the principle of "faries and pixie
dust".

The previous owner had just put a new timing chain on.

Thanks for the feedback, I've got some things to check.

BT3

>> Missing on a couple of cylinders when engine is cold and choke is
> set.
[quoted text clipped - 38 lines]
>
> Whitelightning

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