89 Carbureted 4G52 Stalling Out

[AaronB31]

My truck is starting up just fine. Low speeds/pulling out of parking lots just fine. When I get on the road and start doing 30mph, it bogs and starts cutting out. I barely made it back to the house. It died a couple times but I managed to restart it.

I had this problem about 2 months ago. I rebuilt the carburetor and it ran great. I drove it twice a week for the past 2 months. Now, out of the blue, it is doing the same thing it was doing before.

Any ideas?

[AaronB31]

I should add that I've installed new plugs and wires, and changed the oil recently.

[85Ram50]

Fuel Pump?

[AaronB31]

The thought of it being the pump has crossed my mind, but I doubt that's it since it is idling correctly.

When I have the hood up, I hear a loud sucking air sound coming from the carb area, so I'm thinking maybe a cracked vacuum line.

If that doesn't work, I'll do the cap & rotor. Then on to ignition coil. Will update when I make progress. Someone with ideas and/or experience feel free to point me in the right direction please.

[pennyman1]

check the vacuum lines going over to the silver box on the left fender. It is the computer interface for the carb, and the vacuum lines work with the computer to control the carb. A leak there will cause the exact issue you are having - I had an 88 that had the same issue and the lines were the cause.