1991 GMC Suburban Ignition issues

[geodiggr]

Hi all,

1991 GMC V1500 Suburban, 5.7, 4wd, 700R4, 160k

I am having starting issues with the vehicle. Initially, it was thought to be a fuel pump...but after it finally not starting after 4 months of sitting I have determined that it is a spark issue.

Weather finally started getting colder. Truck would not start. Turns over, but does not fire. Put a spark plug tester on the plugs and no spark. Try it later in the day (warmer), no spark at first...little blip, no spark, then spark and it fires and runs for about 10 secs and cuts off. Tried this test on two different plugs/wires and both had the same results.

Checked the coil today and it seems to test ok...

Problem is, the problem doesn't occur all the time. Seems that it occurs when engine is hot on restarts, when I cut steering wheel hard or to limits, or when it is cold outside. Cold outside seems to be the most consistent no start...so far.

Pulling my hair out on this one...any and all help would be greatly appreciated!

Thanks,
Rick

[unplugged]

Try this:
Pop the distributor cap. If you see a lot of red dust, you'll need to replace the cap and rotor. The red dust comes from the metal in the distributor. The rotor gets a small hole in it and the high voltage from the coil arcs to the metal surfaces under the rotor and oxidizes the metal, hence red rust colored dust/dirt.

[azdrtdog]

Cold engines need hot spark for rich mix i think the problem is always there.just more of a pain when cold. definetly check your cap and if the wires are old maybe replace check spark at cap