Re: [ihc] Scout warm up issues...

["ken.dunnington" <ken.dunnington@xxxxxxxxx>]

Ryan

I'd suspect the obvious.  Three main systems deal with cold start-up
conditions.  The exhaust cross-over system, the choke system, and the
heated intake iar system.  I'd check these three.  Really the first on
the list is the choke system because the other two can be eliminated
and not induce the problems you are having in and of themselves.
However, they may be working some other condition to produce you poor
start-up running.

Take off the aircleaner lid and watch the choke mechanism do its
thing.  See if its activity coincides with problems.  Or perhaps it's
inactivity that causes the problem, maybe the choke should begin
opening sooner than it is.

My money's on the choke as the main, if not only, culprit here.
However, diagnosis via internet is not a strong point of mine.

Ken

RM> This last week I paid particular attention to the scout's warm up to see
RM> exactly what it does when it gets to it's trouble spot.

RM> It always starts great and it'll run perfectly regardless of temp, I'd
RM> venture to guess I could kick off the choke immediately too and it'd be fine
RM> at first.

RM> Here's what happens...

RM> It'll start great and be running along fine.  let it idle to warm up.  It's
RM> running fine.  Then the rpm drops a little. Takes a while before it starts
RM> dropping but once it does it's fairly quick.  A slow and steady decline in
RM> rpm until it bottoms out at around 400 or 500 rpm sounding like it's only
RM> hitting on a few cylinders (I need to get a tach so I can verify the rpms).
RM> It'll stay that way for a while, can't touch anything becuase kicking off
RM> the fast idle will cause it to just die.  It'll do that for a few minutes
RM> and then out of nowhere the idle will bump up a notch, not a whole lot, just
RM> 50 rpms or so, it's a sudden surge.  After that though it starts the same
RM> progression as initially except in reverse until it's at normal fast idle.
RM> Then I can kick the fast idle off and go.   I can drive before then but I
RM> have to be careful to keep some pedal in or it'll die (doesn't bother me too
RM> much, I like to let the scout warm up before driving anyway).  It does kind
RM> of bother me though the way it does that.

RM> It runs really bad during that period.  Sitting there barely hitting, whole
RM> scout shuddering and rocking a little as the engine hits along.  It's going
RM> slow enough that I want to say I could easily count the number of loops my
RM> alternator belt does while it's doing that (yeah a tach would really help on
RM> getting that RPM, I'm kind of curious how fast it's going).

RM> It's a pretty drastic difference.  Takes about 30 seconds I'd say to go from
RM> initial great running to bad and another 30 seconds to get good again after
RM> a few minutes of barely puttering along.  Also, it only does it when it's
RM> cold.

RM> I've tried to mess with the choke some while it's doing that with no
RM> effect... any suggestions on what I should look at?

RM> New ignition module and coil and it did it with the old ones too (which are
RM> now my spares).  Prestolite electronic ign and the infamous stock holley
RM> 2bbl carb...

RM> It's been doing it for a long time, but it's one of those things that kind
RM> of annoys me.... ok, it greatly annoys me, but I have no idea how to
RM> troubleshoot this one.  I don't remember seeing anything about this type of
RM> problem in the troubleshooting section of the service manual.

RM> Thanks,
RM> Ryan