Idle issue.

[jdricha5]

I installed a remaned 2100 from autozone on my 360. When I put everything back together and started the truck the only thing I could do to keep the truck running was make it idle too high. Now im guessing from what it use to idle at. It just seems its idling to high and no matter what I did I lower the idle it would kill. It almost sounded like it was galloping and would kill very shortly after about 10-15 seconds the galloping would sound more rugged before it would kill. The truck runs PERFECT on the highway but when its idling its too high.
Any ideas?

Thanks
JD

[mrtleavitt]

Make sure you don't have any vaccum leaks. A hose may have got missed when you put the new carb back on. Just double check.

[jdricha5]

how do I tell if I have a vacuum leak? I do remember not being able to get all of the old gasket off the spacer before I put the new one on.

[ezernut9mm]

how do I tell if I have a vacuum leak? I do remember not being able to get all of the old gasket off the spacer before I put the new one on.

that's how you tell. i would bet dollars to donuts that's the problem.

[jdricha5]

I have the riser so how do I get all the old gasket off of the intake? Any kind of brush or cleaning product that wont hurt my intake? All I need now I guess is two new gaskets one for the intake/spacer and one for the spacer/carb.

[knightfire83]

Use a putty knife to scrape old gasket remains off. A window scraper that has a razor blade works good too. I usually follow that up with a wire wheel in a drill, then wipe the area own with carb cleaner to remove any left over oils. Just make sure you plug holes with something so wire and gasket bits don't go down inside the engine.

If you want to spend money, you can get special air tools that have abrasive discs specifically designed to remove gasket materials. Think they have a kit for electric drills too.

With the spacer you can do the same. It would be easiest to remove the spacer and take it over to a bench grinder that has wire wheels on it.

Gaskets should be readily available at a parts store for a few $$. 2 barrel Motorcraft, Autolite, and Holley use the same base gasket design.

You could have a bad rebuilt carb too.... I've heard horror stories about re-manufactured carbs from parts stores.

You didn't mention anything about adjusting the idle mixture screws, you will have to do this to get a good idle.

[devilbilly65]

Vacuum leak check, spray carb cleaner around the carb base and at the vacuum tree behind the carb, rise in idle speed indicates leak in that area. Sounds like too rich idle mixture, this is causing the poor idle, I would lean it out by screwing idle needles all the way in and back out 1/2 turn.

Once you have idle speed set, then adjust mixture again"back out one needle at a time until idle speed drops 100 rpm then back in 1/4 turn"

You don't have this problem when driving because the idle circuit is bypassed when the throttle plate is opened up

[Montana71-F100]

I had the same problem. It was a vacuum leak around the bottom of the riser. Spraying carb cleaner or propane helps you to find the general area. A way to find exactly where it is is to hook an air hose to a vacuum port and give about 2 or 3 psi of air. (too much pressure could hurt something). Then hold the choke closed and squirt soapy water from a plastic squirt bottle around the suspected area. You'll see bubbles where the leak is. It's just like finding a leak in a tire. That's how I knew it was the bottom gasket and not the other one. I didn't think of this idea, I found it on the internet but I can't remember where.