Holley Diesling

Sounds like you're on the right track... For any number of reasons, the throttle plates are likely open too far. The extra fuel drawn from the transfer slot will have things running on for Gawd knows how long. Lumpy cams and vacuum leaks seem to the biggest causes of these. I have to add that timing is usually a non-issue.... simply beause I have seen timing blamed improperly too many times.

Remind us of your set-up and maybe we an help a bit more...

I know this is caused by a partially open throttle. But, is there a selonoid on holleys that control this? I've also heard the fast idle screw could be out too far??

Thanks guys!

Brad

.go to your setup in outlook exp and set posting format for newsgroups to text mode, non-html

I used to know about this... I had one car that had an anti-diesel solenoid, it must have been a 73 LTD 351.

The idle stop screw was on that solenoid so that with key off, primary plates were full closed.

Thanks Jim and "Crusty" :)

It's a 1980 Bronco with a 351M, Holley 4160.

And since I got ya.... :) ever since it got cold, anything below say, -10C, in third gear (3-speed C6 auto), at anything under 50kph, even on the slightest incline or when adding just the smallest amount of throttle, it gears down into second. Thoughts on that?

Thanks again guys.

Brad

Here's a long shot for you.... Could either of the rubber hoses for the vacuum modulator line be old and brittle??? This would give a vacuum leak that might explain the after-run. And the high line pressures generated by low modulator signal would give early downshift.

To be absolutely sure about the source of the after-run, I would pull the carb (bring careful not to turn it upside down) and check the throttle blades.... Above the little hole for idle feed on each primary is a slot (transfer slot we call it). This transfer slot should not be visible with the choke open and throttle closed (looking from the bottom. If you have a fairly agressive cam, or any other problem that reduces the vacuum signal to the carb, the first inclination is to open the throttles (using the adjustment screw) to achieve idle... *most* times, this will give a highish, "thready" (hard to find a good word) idle... sometimes seems like the change from park or neutral to a gear drops the rpm a lot more than it should..

Tough for the old guy to describe after a frustrating evening with a recalcitrant V10...

Gotcha Jim. That modulator is the first place (and the easiest) :) I'm going to look. I'll bet you that's it - just got a feeling.

Thanks man.

Brad