gets hot (warm?) and dies, HELP!!!

[sactoC10]

My truck left me stranded in front of my ex's house tonight when I dropped off my son after soccer practice. I was NOT interested in having her or her new husband come out to assist (feeling a bit awkward at this point for sure). It was so bad, I pushed the truck in front of the next door neighbor's house just to get out of view!

So anyway, I've now had this truck for a year and this has been consistent. After a 30 mins or so of stop and go driving, or sitting idle for 10-15 minutes it just puts out slowly and dies. It hesitates from a stop and feels as if it is getting flooded, yet it does not smell like gas at all.

What is going on with my truck? Too much fuel, not enough fuel? Air problem? Only thing I've really changed since getting it is the open air filter. Please advise... I love my kids, but don't need to spend any extra time in front of my ex wife's house again!

[Longhorn Man]

Points or HEI ignition?
Any idea how long since it has had a full tune up?

[da-burb]

An off the cuff guess is the control module in your HEI if you have one. They are heat sensitive and prone to dieing when over-heated which ideling and stop and go traffic produces.

Other that that you need to become the detective, the CSI of truckology. The next time it dies, check the carb to make sure you still have gas when you give it a couple of pumps. If you have gas then look for spark. Take a spare spark plug, pull a wire and crank it over. It may take some doing to find a place where you can see the plug and crank it over. If you have spark and gas you should have a running engine.

[RON WOODGEARD]

It could be a couple of things, I'll go over my past experiences in some form of order.

#1. Fuel line too close to Manifold, Causing "Vapor lock" ( this sounds like what it is !) The way to check this, or prove it, Would be to remove the metal fuel line between the Fuel pump and the carb, Replace it with rubber hose.
#2. Dirty fuel filter, either in the fuel line, or the carb itself
#3. Float out of adjustment
#4. the last being a Fuel Pump

OH, Yea, I also remember one time many years ago, I had an International 4X4 that would run for a while and die, Give it a few minutes turn it over and it would fire and run again, only to do the same thing somewhere down the road,,, I had sticks in the gas tank, and they were sucking into the fuel line pickup, then when the engine died, or you turned it off, They would float back up to the surface..

[sactoC10]

jeez, could be any of these things...

Points, no HEI at this time.

Last full tune-up? GREAT question.

Fuel line does not look too close to the manifold, but vapor lock sounds possible (just ran outside to take a peek).

It has one of thos HUGE A** filters that was in-line for the main tank and the auxiliary tanks (all three)... removed the aux tanks, but maybe that filter is the first place I should check.

Along those lines, when this happened at the car wash last week, it felt (and sounded) like it was running out of gas.

Today it final cranked up when I floored it after I realized it may not be flooded since I did not smell any gas.

Great ideas, at least I have a place to start. THANKS!!!

Keep them coming, in order of where I should start. Fuel filter before points? Truck doesn't idle rough, sputter or back fire... just likes to shut off after running for a while.

[71Longbed]

points ? you should get new rotor cap wires i suggest HEI if the engine is over heating Flush the radiator with your hose and a pressure nozzle go down to your local parts store and aquire a 180 degree thermostat and engine overheating will be no prob dont forget the atifreeze and water tho

[sactoC10]

When I say "gets hot" I don't mean overheated. Radiator was replaced in the last few years with a nice heavy duty one. When I say gets hot, I am referring to operating temperature! Thanks.

[emmett]

Does it have a mechanical fuel if it does check or replace it I had a chev. van that did the same thing when pump got warm would not pump gas thus motor died

Good Luck EMMETT

[bouncytruck]

My '69 Blazer was having a problem were it would die constantly when it was warm. It turned out to be the plug into the back of the ignition switch was melted. Mostly caused by the PO's "creative" wiring, but worth taking a look at.

[Mudder]

A bad coil will act like that also.

[jlmtrout]

Will it restart after it sits for a while? I had a Monte Carlo w/455 Olds that would die and not restart until it sat for a few minutes. Turned out to be partially clogged fuel filter. Also, look at rubber fuel line under passenger side of cab to see if it is collapsing. Good luck and keep on truckin'......Jerry

[chevymaz]

Mine was doing the exact same thing. After I drove about 30 minutes it would start sputtering and die. I tried several things with no luck...then I put a 1" phenolic carb spacer on and it took care of all my problems.

[sactoC10]

Great Gosh A'mighty, seems like it could be dozens of things eh? OK, to answer some more questions.

Yes, it does restart after sitting for a few minutes, anywhere from 5-15 minutes, as if there was never a problem.

Bouncytruck, which melted plug? I only ask this because the systematic tear down of this ride has revealed at least one melted plastic wiring cover, the multi one that inserts into the A/C fan switch. Yet if there is one, then there may be another someplace, very interesting.

Emmett (Smith?-j/k), yes it is a mechanical fuel pump and I do have another one. I'm thinking that this is a fuel related matter, so maybe that's it.

Mudder67, I'll go the spark route after I go the fuel route, thanks.

Jlmtrout, will check the filter first, then the lines, then the pump. Not too much rubber there though, seem to be aluminum most of the way.

Chevymaz, won't mess with the carb for a while.

I'm really thinking that it is fuel related, whether it be a problem at the tank, big fuel filter, or up front at the pump. All the while that this has happened, it's seemed as if it is not getting fuel. I just can;t figure out how the heat or time running is making a difference. It starts up easily from cold every time.

[chevymaz]

mine was a fuel problem as well, when the engine got hot it would boil the fuel (vapor lock)...you could actually hear it.

[bouncytruck]

The plug into the back of the ignition switch. I bought a new one through ChevyDuty with pig tails to splice into the wire harness. If you look under your dash behind the ignition, ya can't miss it.

[sactoC10]

I just realized something...

When I got this truck, the exhaust had been split, but rather uncoventionally. The exhaust pipes lead down the exhaust manifolds and run outside of the frame just where it bends straight to lead toward the back of the truck (this make sense)? The pipes then continue back, on the outside of the frame rails.

Last week I tightened up the nuts where the pipes meet the manifold exits. In doing this, I think that the pipe on the passenger's side may just about touch the frame. With the fuel lines right there in the frame with those hot gasses exiting the engine close by, would that create enough heat after driving for a while to create a vapor lock at that point in the lines, to where the fuel can barely even get to the fuel pump?

This may be the problem. As I stated, the truck has had the problem as long as I've owned it. It seems to have worsened in the last two weeks, as it has taken less time to cut off since the "repair" was made. Also, it happens exclusively when the truck is not moving, and there is no cooling taking place on the frame rail or the pipe.

What do you think?

[Hotrod70C10]

This is going to sound really stupid but, I had this same problem that you are describing. Check and see if the bolts / nuts that hold your carb down on the intake are tight. I never checked it and I was getting stranded evertime I would kill the truck after it got up to operating temp. After it cooled off it would start again. I didn't find this out until I was pulling the carb off to replace it only to find that the bolts were less than finger tight on the front side. I tightened them down and fired it up let it run to operating temp, killed it and fired it right back up.... Then I put my new carb on... lol I'm lucky that the thing never burst into flames......

[ddsmith]

Hot operating temperatures indicate a lean fuel charge to the cylinders and this will drive temperature up. You should not have a fuel filter on the suction side of the pump. It should be a straight shot to the suction of the pump and the filter should be on the discharge side. Vapor lock is a possibility but I had a exhaust manifold donut gasket leak which dumped lots of hot gas down in the starter area. It didn't give me vapor lock but the starter wasn't to happy. I would follow the suggestion about the next time it happens to look down the carb throat and give it a couple of pumps. You should get nice solid streams of fuel from the accelerator pump/s. If you don't then I would check your fuel supply side and resolve the problem.

[sactoC10]

OK, ddsmith, I hear ya.

The filter that I have is at the frame of the truck underneath the cab, where it could filter the fuel from all three tanks down the line from the switch, en route to the pump. The pump does NOT have a filter between it and the carb, where they typically are found.

You are telling me to get rid of the one between the tank and the pump, and put one between the pump and the carb, right?

[RON WOODGEARD]

Originally Posted by sactoC10

I just realized something...

When I got this truck, the exhaust had been split, but rather uncoventionally. The exhaust pipes lead down the exhaust manifolds and run outside of the frame just where it bends straight to lead toward the back of the truck (this make sense)? The pipes then continue back, on the outside of the frame rails.

Last week I tightened up the nuts where the pipes meet the manifold exits. In doing this, I think that the pipe on the passenger's side may just about touch the frame. With the fuel lines right there in the frame with those hot gasses exiting the engine close by, would that create enough heat after driving for a while to create a vapor lock at that point in the lines, to where the fuel can barely even get to the fuel pump?

This may be the problem. As I stated, the truck has had the problem as long as I've owned it. It seems to have worsened in the last two weeks, as it has taken less time to cut off since the "repair" was made. Also, it happens exclusively when the truck is not moving, and there is no cooling taking place on the frame rail or the pipe.

What do you think?

You may have found something, especially since it has worsened since a change was made. AND, it happens when you are not moving. Vapor lock is the "Boiling" of the fuel in the fuel line. This used to be quite common , but with the isolation of the fuel delivery from the heat source from the factory it has subsided to almost nill.
What you need to do is Isolate the fuel line from any or at least most of the heat. You may be able to do this by cutting a thick tin can up and wiring/bolting it between the fuel line and any heat source. ( Not touching either ) Now that our area is starting to cool down again, This problem should be less frequent because of the cooler weather also. But once you Have the heat source figured out, Get it fixed permanently.. IE: New exhaust, YEAAAAA...

[Longhorn Man]

Placing the filter between the tank and the pump reduces the pressure in the line more than if it had no filter there. Reduced pressure lowers the boiling point.

[Harold Shepard]

I thought I would add to this. My truck, just afer a total frame off would sputter and buck like it was running out of gas, but only in a pulling situation. 1st thought was line stopped up, long story short, it was the fuel filter in the carb that was stopped up. Change the filter first it's cheap and then go from there....

[sactoC10]

Yes, probably the filters...yes filter(S), my truck has two! It has the one at the carb from the pump, then the other one back under the cab at the frame. Gonna remove the big extra one and replace the small one. I'll let ya'all know what happens.

[monsgard]

timing chain