Hello all, First post so I hope I'm doing this right. This is going to be kind of long so sorry in advance about that. I have a 1985 D250 with the 360 V8. It has an Edelbrock intake, a 3310-11 Holley carb and maybe a mild cam. Not sure on the cam cause the guy I bought it from likes to bs people to justify his high asking prices. I took it out of a 2 1/2 year storage about 2 months ago. Fresh gas and a new battery and it fired right up and ran perfect for approx. 3 weeks other than the time the choke decided to close on its own.

I was going up a mild incline at about 50mph and the engine bogged down like it was low on gas. I pumped the pedal a few times to see what it would do and if I got it in the right spot it would run for a couple seconds the do it again. Pulled over to the side and when I let off the gas completely it stalled. Pumped the pedal twice and it fired right back up and ran fine to where I was going. On the way back it did it again and continued to do it 7 more times in the next half hour until i got home. Drove it the 2 miles to work and it did it again. Most of the times it was pulling up hill at around 45mph but a couple times was on flat sections of road going slightly faster.

After talking to a couple people at work it was decided it really should have a tune up. I replaced the plugs, wires, cap, rotor, fuel filter, fuel pump and rebuilt the carb. It made no difference. I strapped a 2 1/2 gallon can to the inside of the fender and hooked it to the pump and it ran perfect. Let it sit for a couple hours so i could clear out a space to drop the tank and when I went to bring it in I could barely keep it running because it siphoned the gas out of the can back into the tank. Hooked the tank back up and it ran fine for a day.

The next day it started skipping. Get it running and have to rev it up to at least 1100rpm to make it stay running while in gear but it would skip so bad the truck would shake. Checked the timing and plugs but couldn't find anything. Checked the dist. and the shaft had noticable wiggle in it. Put a reman one in along with a new water pump because that decided to leak too. Ran better than ever for 3 miles then bogged out going up a hill at 50mph. Let off on it and put it in neutral and it stayed running as i coasted about 3/4 of a mile down hill to a gas station and had to put it in gear to get off the road and it was skipping again. Made it home and went to the store the next day to get the ignition control module, ballast resistor, and coil.

Coming home it died just like it ran out of gas. Put 4 gallons in and it started after about a minute of cranking and ran horrible for about 30 seconds and smoothed out and ran perfect. Got it to work and dropped the tank and drained approx. 12 gallons of gas out. Flushed the tank as best I could, cleaned the sock on the sending unit, and replaced the rubber lines everywhere. Still did the bogging out at about 45.

Put in the ICM and resistor and let it run while i bumped up the idle speed a little so it would run smoother and let it run for 15 minutes and it stalled. Pulled the sight plug on the float chambers and they were empty. Readjusted them and got it running and took it for a drive. Dead on the side of the road from no gas in the carb. Pulled the sight plug and it started up, drove till it ran out of gas again and had it towed to work. Filled the float chamber through the tube sticking up in the intake and it fired right up but now the float level is too high. Drove it around as hard as I could without the air cleaner on it which is about the size of one on a 20hp lawn tractor engine and it ran better. I was able to make it bog out but i was doing about 75 going up hill. Put the air cleaner back on and it was back to skipping a little and bogged out at about 45.

Any ideas on what direction I should go? I really need the truck to tow the trailer at work so I need to get it fixed.

Thanks in advance, Stewart

 

It sounds like you are getting vapor locked(no liquid fuel to the carb). This happens when the fuel temp gets to high in the fuel line running to the carb. You need to keep the fuel line away from heat sources(headers) or insulate them.

 

Well I'm back at it trying to get the truck running right. Had to walk away for a few days as I was getting to the point where I was going to end up doing something to it I'd regret later. I did find that 10 of the 12 bolts on the intake took almost 2 full turns to get tight/torqued and sprayed wd-40 all along the gasket seams to see if they were leaking. There wasn't a noticable change in how it ran. I think I've ruled out a vapor lock issue as I let it run for almost 2 hours and get good and hot during the week on a couple hot days and then sprayed from the fuel pump to the carb with cold water and immediately took it for a drive and it still will die out. Changed the fuel pump back to the old one today with a new filter just to make sure it wasn't the new pump then started it and let it run maybe 5 minutes while I put some gas in and took it up the road and it did it again. Plan for tomorrow is to put an electric pump in and run the line from the tank to the pump and into a can to see what kind of flow there is. If it's questionable then I'm going to order a new sending unit and put it in. I also plan on talking to a local guy I know that does a lot with the Holley carbs and see if he'll look over mine to see if there might be something I missed when I rebuilt it. Stewart

 

Put a Facet electric fuel pump in this afternoon and have driven it about 15 miles without any issues. Going to get on the highway with it tomorrow at some point and see if it does it then. I really hope it doesn't. When I had the tank out I wasn't real happy with all the kinks in the sock filter on the end of the sending unit. Found a couple different people on ebay that sell new sending units with an actual filter on the end so I think I'm going to get one put it in and unhook the electric pump and see if it still does it. If it doesn't great I'll take the electric pump out and be happy it's fixed. If it does then I'll wire in the pump permanent. Stewart

 

I have the exact same problem. Electric pump did not help. I am running from a new auxiliary tank with electric pump. Problem started when I forgot to fill up with gas and ran low on gas. Pulled into a station I had never used before. Bought $20 of gas and it started running ragged, a block from the station. The next day when I drove by the station all of the pumps were blocked and the tanks were being serviced with hoses running everywhere. I suspect the idle circuits of the stock two barrels are stopped up. Have you resolved the issue with your truck? Mine is 85 with 318..