[net.auto] Intermittent starter problem

reg@whuxl.UUCP (Gunderman) (08/14/85)

I would appreciate any info re:
A 79 Chevette starter that will not turn over when the engine is very hot,
such as when driving 25 miles on the highway with the air conditioner on
and then stopping for about 15 to 30 minutes and then trying to start the
engine. This condition is not constant - most of the time its turns over.
		Dick Gunderman

jeepcj2a@fluke.UUCP (Dale Chaudiere) (08/16/85)

> I would appreciate any info re:
> A 79 Chevette starter that will not turn over when the engine is very hot,
> such as when driving 25 miles on the highway with the air conditioner on
> and then stopping for about 15 to 30 minutes and then trying to start the
> engine. This condition is not constant - most of the time its turns over.
> 		Dick Gunderman

You probably have what is referred to as a "flat spot" in your starter.  This
occurs when there is an open or high resistance in one of the windings of the
starter armature (sp).  If the starter stops at the right point it will draw
more current than usual or not turn over.  The engine is tighter when hot, so
the battery may not be able to supply the current to turn over the engine.

Solution, rebuild or buy a new starter.  It is a very irritating problem.

By the way, I posted a followup because my system never seems to find the
sender if try to use reply.
.

irwin@uiucdcs.Uiuc.ARPA (08/20/85)

I would bet that the armature is rubbing the fields in the starter. When
the starter gets very warm from the warm engine, the armature and the
fields expand. If the clearance between is very close when cold, it will
be even closer when hot and may actually touch. If the bearings in the
starter are worn slightly, it could allow the armature to shift to the
side slightly, causing the low clearance. You would have to remove and
disassemble the starter to look for signs of wear on the fields or the
armature to prove the theory.