Engine Stalling

[LeadHead]

A few days ago, my truck stalled on me (in an intersection, of course ) and I figured it was maybe the fuel pump, or something worse. I put on a new fuel pump, and that didn't do nothing. It stalled on me when I was on the brakes. So, I got it started and made it home. I went a half turn on the curb idle screw. Ran better, but still dropped scary low and almost stalled when I was braking or stopped. Another half turn later, it worked, but the idle seems way high. I'm idling at around 20mph . Anyways, would yall happen to know what the problem is? I'm thinking the carburetor is messed up, or something worse.

I do have a bottle of SeaFoam. Think that may be the cure? Thanks yall!

Edit: I feel like the high idle speed is only covering up the engine wanting to stall, but I want to cure it so I dont gotta worry when braking (steering locks up and brakes suck and could be real dangerous)

 

[HotRodPC]

If you adjusted the carb and it raised your idle, the you improved your idle and carb adjustment. You'd have to turn your idle screw back down to compensate for that. But 1/3 of your SeaFoam in about 10-12 gallons of fuel and let it run thru the carb and see if it cleans up the carb any and improves your problem. Usually just stalling like that you explain, is carb related.
Its only happening at low speeds or when the rpm is low? It doesn't do it if you're cruising like 40mph?

 

[crazy4offroad]

What kind of carb? First guess would be high-ethanol gas is taking its toll on your rubber fuel lines, stopping up your fuel filter(s) and idle circuit of your carb with what looks like black sand (little bits of rubber).

 

[LeadHead]

If you adjusted the carb and it raised your idle, the you improved your idle and carb adjustment. You'd have to turn your idle screw back down to compensate for that. But 1/3 of your SeaFoam in about 10-12 gallons of fuel and let it run thru the carb and see if it cleans up the carb any and improves your problem. Usually just stalling like that you explain, is carb related.
Its only happening at low speeds or when the rpm is low? It doesn't do it if you're cruising like 40mph?

Thanks! I will do that tomorrow.

Yes, that's correct. Only stalls when I'm going slow while slowing down for a stop or turn.

 

[LeadHead]

What kind of carb? First guess would be high-ethanol gas is taking its toll on your rubber fuel lines, stopping up your fuel filter(s) and idle circuit of your carb with what looks like black sand (little bits of rubber).

Sorry about that. It's a 650 Holley on a 350 engine.

 

[HotRodPC]

Yep, sounds to me like a carb issue for sure. Holley's don't like getting anything in the idle circuit at all. I have a feeling if you just pull the front float bowl, and the metering block off the carb, clean all that out, put it back on, you'll probably be good to go. You can even do that without removing the carb if its the Holley I think it is.

 

[HotRodPC]

And for those who don't know, there are now rebuild kits for carbs that will make them OK for ethanol use. A bit more pricey, but just about a requirment these days.

 

[dhamp]

A really crappy dist cap & rotor makes mine do it sporadically, but mostly when it's raining or very humid. Plus mine is TBI, so not sure if it's relevant.

 

[89Suburban]

 

[LeadHead]

Well, I ran some Sea Foam through it and it didn't help. Truck is back to stalling. It works fine when it first starts up, but I'll drive around the block two times, and it starts stalling out.

I took the air filter off the carb and opened the throttle and steam came out. Should that happen?

I'm not so sure it's the carb anymore. What do yall think?

 

[89Suburban]

Did you check your fuel filter?

 

[Irishman999]

Did you check your fuel filter?

x2, I would look into your fuel delivery system. Just a couple weeks ago I took the fuel line loose at my carb to find it packed full of black particles, after the fuel filter.

 

[LeadHead]

Did you check your fuel filter?

Yeah. It's got some little black particles swimming around in there. But it's pretty new. My old one fell apart a few months ago.

x2, I would look into your fuel delivery system. Just a couple weeks ago I took the fuel line loose at my carb to find it packed full of black particles, after the fuel filter.

Ok, I'll do that.

 

[89Suburban]

Put a new filter on, pull the feed line at the carb and crank the motor to pump some into a bucket to clear the line out, then I would open up the carb and check it for dirt like mentioned earlier here.

 

[HotRodPC]

It could be the fuel filter since low rpm the pump is not pump hard enough to pump the junk through the filter, but normally, when a fuel filter is bad, you're more likley to have issues at higher rpm, cuz the fuel flow can't keep up through a dirty filter.

I'm still going with a dirty idle circuit in the metering block. Maybe best to remove the primary float bowl, and metering block. Clean all the passages out with carb cleaner and an air nozzle with high pressure. You should be able to do it without need for a kit. Worst case scenario you might need to replace the bowl gasket if it tears.