Engine dies after letting of gas pedal

[COjeeper]

Hey everyone,

So when I got my 87 wagoneer the thing wouldn’t go over 15
Mph and I had to have it trailered home because the motor wouldn’t stay running. Fast forward a month and she’s idles like a champ now and it’s running great but for one problem. When I get on the gas pretty good it’ll run but when I let off it dies, I can’t tell if I’m starving it or flooding it, most of the time it will fire right back up. When I got the Jeep it had a new Holley carb that had the factory 74 jets in it, I live at nearly 8000 feet so I went down to 63 and it made a huge difference but not sure if I went to far or not enough. Any advice would be great, thanks.

[TUDrewser]

We are dealing with something similar, though we also had some lousy idle, especially when cold. We've been chasing vacuum leaks and it's slowly getting better. Replaced distributor as the vacuum advance was not working (and maybe leaking?) and that helped some too. I'm wondering if our EGR is gummed up...that's the next thing to check.

I'm sure you've already checked stuff like this but figured I'd at least share in your frustration

[will e]

My Ouray notes say I run 61's in my Holley Truck avenger PRIMARY and this works well.

What Holley carb are you running? What are you running for the secondary jets? Is it a manual secondary or vacuum secondary?

Is it pretty consistent in its stalling? So you get on it pretty good and then totally let off or reduce the amount of throttle?

When you are loading the engine your manifold vacuum is at it's lowest. As soon as you reduce throttle it will reach pretty much the highest value it ever reaches, even more than at idle, at least for a moment. So it might be a vacuum leak. Or perhaps you are getting 'too much' advance on the distributor (this seems like a long shot but we've seen weirder thing). I would disconnect the vacuum advance for the distributor (make sure to plug the vacuum hose). Then take it for a spin and see if you can duplicate the issue.

[COjeeper]

So I went to the store and bought 10 feet of every size vacuum line I could find and started replacing every hose, the thing runs great now! I also adjusted the float to be a little higher than Holley says it needs to be. Just drove it 20 miles through the mountains to the exhaust shop and didn’t have a single issue. I’m thinking I had a vacuum leak and ended up fixing it when I was replacing hoses, thanks for the response and I wish you the best of luck but it is nice to know others and sharing the misery .

[COjeeper]

So I went to the store and bought 10 feet of every size vacuum line I could find and started replacing every hose, the thing runs great now! I also adjusted the float to be a little higher than Holley says it needs to be. Just drove it 20 miles through the mountains to the exhaust shop and didn’t have a single issue. I’m thinking I had a vacuum leak and ended up fixing it when I was replacing hoses, thanks for the response and I wish you the best of luck but it is nice to know others and sharing the misery .

[TUDrewser]

Awesome! Nice work!