Truck dies while idle

[utee05]

Hi all,
I have been scratching my head on this one. While driving around town my truck has died on me twice.

The first time it was while I was in line to park in a parking lot. The second time I was waiting at a 4-way stop.

Both times I tried to turn the truck right back on but it refused. I had to get a jump to get it up and running again. When I checked the battery voltage it was at 12.4 before getting jumped. When the truck is on the voltage jumps to 14.4 so this means alternator is good.

I will say that both times I had around 1/4 tank of gas so I'm suspect that it could be something fuel related. The reason is cause I was in traffic last night and the truck held up fine, though I had nearly a full tank of gas.

I replaced the wiring going to the junction block as it looked a bit worn at the connection. I replaced this after the truck died on me.

Mods done to the truck: headlight relay, aftermarket stereo.

Any clue as to what could be causing the issue? I checked voltages from starter to battery and ground and all looked good.

[truckster]

When you tried to restart, did the engine crank and not fire, or did it refuse to crank?

[utee05]

It did not want to turn over. So the engine did crank but no fire.

I know the point dist was replaced about a month before I got the truck so it has been on there for about 6 months.

[1990SSchevy65]

This is what I love about old cars and trucks.

It only takes Air, Fuel, and Spark to run the engine. You seem to have eliminated spark, since the battery, alternator are fine and since the points dist was replaced recently it should still be good.

You said that you were at 1/4 of a tank of gas the two times it died. When was the last time the fuel filter was changed? I know in some carbs that there is a filter inside it as well. Maybe it is time to replace those?

[utee05]

Not sure on the fuel filter. I know the carb was worked on but not sure what all was fixed or replaced.

I have a rochester q-jet T4-478. I am pretty sure the fuel filter is inside the carb.

Yup the gauge read around 1/4 of a tank so that is what got me thinking that it could be something fuel related.

[ole dollor]

you said you were still running a point dist. might want to change out the points and cond. i have known a lot of cond. that over heat and have to set a while and cool before they will let the points fire again. if you have a uniset replace it , if the cond. is seperate from the points just replace the cond. and give the wiring a good look at the dist. good luck on your truck..

[Tynee]

I'm on board with the fuel filter thing, FWIW. Next time it dies, before you do anythign else, pop the hood, take off the breather cover, and look down the throat of the carb while you work the the throttle. If you see fuel spraying, you probably down't have a fuel problem. If you DON'T see fuel spraying, then you most likely have a filter or pump issue.

If it were me, I'd replace all the fuel filters you can find on the truck. If you don't know when it was done, it's probably time anyway, and it can all be done for $15.

Good luck.

[utee05]

Yup I was going to go ahead and replace all of the fuel filters that I can find. Was planning to work on this over the weekend.

Downside is that if the truck dies I am usually out and about so maybe I can replicate it when I am near home to try that theory out.

[utee05]

Well I replaced the fuel pump and lines. It looked fine but I noticed that the lines were crossed. Not sure why they were connected this way but I corrected that. Now to drive the truck around and see if this helped.

I looked at the fuel filter but it looked pretty clean to me. I was going to replace this but got the wrong part so will need to go back and get the correct one.

[Ol Blue K20]

Originally Posted by ole dollor

you said you were still running a point dist. might want to change out the points and cond. i have known a lot of cond. that over heat and have to set a while and cool before they will let the points fire again. if you have a uniset replace it , if the cond. is seperate from the points just replace the cond. and give the wiring a good look at the dist. good luck on your truck..

I agree with Dollar, I would be suspicious of the Condenser

[utee05]

Ok I will check out that as well. Didn't look at initially since I suspected that it was good but might as well.

So I should probably change out the distributor cap/rotor and condenser and possibly point set? Or would I be better off just moving to HEI?

Anyone have images of a uniset? I can take some pics of my setup as well to show what I currently have.

[SCHRUMGMC]

It may be the Aftermarket Radio..I have a Jetta and one was put it and it killed my Battery

[utee05]

Though the issue is that when my truck has died the voltage at the battery was still around 12.4V. If the battery was being drained it would be a lot lower.

The tricky thing is that I needed a jump to get the truck going again even though the voltage at the battery was good.

One thing that happened to me the other day was that the truck did try to turn off while I was actually driving. I just kept pumping on the gas pedal and luckily it stayed on. This was before I replaced the fuel pump and lines.

[utee05]

Well while working on my truck I noticed that my point cond was not connected up properly. The wire was loose. I went ahead and replaced the point cond and the ignition coil while I was working on it. So far the truck is running ok but I wont' know till I get the gas down a bit more and see if the truck dies on me again.

[RoughKuntry]

So what happens if the the carb is spraying hot fuel out the top? What are you supposed to do then? take for instance my 73 Super Custom 350 5.7 v8 was just doing that yesterday? I pulled off the road to unlock the hubs and kick her out of 4 high, and I got nothing no spark just nothing. Should I just take this to my mechanic and have him check it out?

[ole dollor]

Originally Posted by T.Rokk

So what happens if the the carb is spraying hot fuel out the top? What are you supposed to do then? take for instance my 73 Super Custom 350 5.7 v8 was just doing that yesterday? I pulled off the road to unlock the hubs and kick her out of 4 high, and I got nothing no spark just nothing. Should I just take this to my mechanic and have him check it out?

well to get back home I would tap on the carb. right around where the float would be...on a q-jet. sounds like your float is heavy , or some trash in the needle and seat. but that want fix the no spark problem. you did not say whether you had points or hei, you lost fire some where, yes a good mechanic should be able to fix you right up...good luck.

[Don Quixote]

Just an isolated thought, if it dies and required a jump with a good battery, check your starter selenoid. If it's cracked and moisture gets in or it is simply heat soaked, it won't transfer the voltage to anywhere from anywhere. On a GM, it is the middle man for the whole electrical system.

[WIDESIDE72]

Originally Posted by Don Quixote

Just an isolated thought, if it dies and required a jump with a good battery, check your starter selenoid. If it's cracked and moisture gets in or it is simply heat soaked, it won't transfer the voltage to anywhere from anywhere. On a GM, it is the middle man for the whole electrical system.

Very good point on the solenoid. I had almost forgotten about that!

[RoughKuntry]

Originally Posted by Don Quixote

Just an isolated thought, if it dies and required a jump with a good battery, check your starter selenoid. If it's cracked and moisture gets in or it is simply heat soaked, it won't transfer the voltage to anywhere from anywhere. On a GM, it is the middle man for the whole electrical system.

That's a great point, however. I replaced mine two weeks ago, and yet my truck still will idle and die, then not want to start up, I leave it alone for a while come back and then i need to charge the battery again.