Pebcak Posted January 20, 2018 Share Posted January 20, 2018 For the past 6 months or so I've had an intermittent problem. When I get up to 55-65 in the Beast it'll bog down like it has a governor/isn't getting enough fuel. When I slow down to 45ish it'll be fine until I get up to speed again. Luckily for me I only do 45ish going to and from work back roads so it hasn't been an emergency. Here are some point of troubleshooting I've done. - Doesn't matter which tank is selected. - Happens in cold or hot weather. - I've tried different gas stations. - Checked lines and changed the fuel filter less than a year ago. - Up until about 55 mph the truck idles and runs fine. It's totally random when it happens. I talked with one of my coworkers and he had a 70's model when he was growing up. He said to go ahead and change my fuel filter again and put a bottle of isopropyl alcohol in each tank to absorb any water. With those suggestions, I went under to trace everything down to get parts I noticed a mess underneath. Now I'm thinking I should run new lines from the tank selector all the way to the engine bay. With this project I have some other questions. - Can I just run new (fuel rated) hose all the way from the tank selector into the engine bay and put the fuel filter in the bay? - I'm not good with hoses so I need to ask if I should go with Steel or can I use fuel rubber hose? - What diameter should I use for a 351W? 5/16" or 3/8" I see the part # of 9289 on the IPB but can't find the measurement in the part # area. - I took a picture of what I think the tank selector is and wanted to make sure that this is correct. What is all the stuff that the lines "use" to go through on the left side of the photo? Here's the fuel filter my son replaced about 10 months ago. I apologize in advance for the multiple questions. As always, I want to fix this and do it right the first time. If I can improve or make things easier in the future I will. Any suggestions or comments (good or bad) are more than welcome. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 20, 2018 Share Posted January 20, 2018 You can replace all that stuff, but I don't think it will solve the problem. I say that because I don't see anything wrong with what is there. (And, by the way, the thing to the left of the pic is probably the original fuel tank selector valve.) Since it happens on either tank it is something in common with both tanks. And I can think of a few things it could be: Float Level: If the float level in the carb is low, you could be running out of fuel in the carb, but have enough flow to the carb. The Edelbrock Owner's Manual explains how to set the float level. Vent: The tanks are vented via a small line that tees and then goes to the evap canister under the battery. If that line is pinched after the tee, or if the evap canister's vent is plugged the tanks can't vent properly and you'll pull a vacuum on the tank and prevent the fuel pump from doing its job. You could test this theory by loosening the gas cap for a drive. Fuel Line: Or, it could be that the fuel line going from that valve in the picture, through the fuel filter, and on to the carb is leaking at a joint. Any looseness in a connection can allow air in and that will kill the pump's suction. As for replacing the line, yes you can use rubber hose. Get the stuff that is ethanol-rated. As for size, I'm not sure. I thought it was 3/8", but I wouldn't swear to that. Link to comment Share on other sites More sharing options...
Pebcak Posted January 20, 2018 Author Share Posted January 20, 2018 You can replace all that stuff, but I don't think it will solve the problem. I say that because I don't see anything wrong with what is there. (And, by the way, the thing to the left of the pic is probably the original fuel tank selector valve.) Since it happens on either tank it is something in common with both tanks. And I can think of a few things it could be: Float Level: If the float level in the carb is low, you could be running out of fuel in the carb, but have enough flow to the carb. The Edelbrock Owner's Manual explains how to set the float level. Vent: The tanks are vented via a small line that tees and then goes to the evap canister under the battery. If that line is pinched after the tee, or if the evap canister's vent is plugged the tanks can't vent properly and you'll pull a vacuum on the tank and prevent the fuel pump from doing its job. You could test this theory by loosening the gas cap for a drive. Fuel Line: Or, it could be that the fuel line going from that valve in the picture, through the fuel filter, and on to the carb is leaking at a joint. Any looseness in a connection can allow air in and that will kill the pump's suction. As for replacing the line, yes you can use rubber hose. Get the stuff that is ethanol-rated. As for size, I'm not sure. I thought it was 3/8", but I wouldn't swear to that. Awesome ideas Gary! I'll try the gas cap part out the next time I drive it. It's going to be parked this next week until I get my allowance and time to work on it. This weekend is full but next weekend is free for now. One follow up question. Is it an issue if I redo all the hose and put the fuel filter up in the engine bay somewhere? For the ease of R&R? Or is there a physics/design reason it's on the frame below? Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 20, 2018 Share Posted January 20, 2018 Awesome ideas Gary! I'll try the gas cap part out the next time I drive it. It's going to be parked this next week until I get my allowance and time to work on it. This weekend is full but next weekend is free for now. One follow up question. Is it an issue if I redo all the hose and put the fuel filter up in the engine bay somewhere? For the ease of R&R? Or is there a physics/design reason it's on the frame below? From the factory the filters are always after the fuel pump. But yours is before. I've run one before the pump for years on several trucks with no problems, but there are those that say you shouldn't do that for fear of restricting the pump. So, perhaps that is what is happening, and if you put it in the engine compartment you could put it after the pump. Maybe that will fix the problem? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted January 20, 2018 Share Posted January 20, 2018 Adding an 8oz bottle of alcohol to a tank of fuel that already has 12.8oz *per gallon*(10%) is very unlikely to do anything. Back in the day adding drygas allowed a polar solvent to be miscable in a non-polar solvent, because it will mix with both. You either have a fuel restriction or an ignition that is breaking down at higher rpms. Figure a way to determine if your miss is load or rpm dependant. Drive in a lower gear on flat ground for a few miles. Drive in a high gear up a long hill. Do either of these cause it to happen, or be worse? "It's totally random when it happens" is not a valid conclusion. SOMETHING causes it to happen... Link to comment Share on other sites More sharing options...
PetesPonies Posted January 20, 2018 Share Posted January 20, 2018 Adding an 8oz bottle of alcohol to a tank of fuel that already has 12.8oz *per gallon*(10%) is very unlikely to do anything. Back in the day adding drygas allowed a polar solvent to be miscable in a non-polar solvent, because it will mix with both. You either have a fuel restriction or an ignition that is breaking down at higher rpms. Figure a way to determine if your miss is load or rpm dependant. Drive in a lower gear on flat ground for a few miles. Drive in a high gear up a long hill. Do either of these cause it to happen, or be worse? "It's totally random when it happens" is not a valid conclusion. SOMETHING causes it to happen... Fuel delivery is extremely important with a fuel injected engine. There is no extra fuel ready, like in the bowl of a carburetor. If this only happened after WOT situations, a moment after being in WOT, I could see it being a fuel delivery issue. But there is enough fuel in the bowl to allow you a couple miles in most instances. So if this happens as soon as you reach over 45mph . .its not delivery, at least not outside the carb. Fuel delivery inside. absolutely. Low level, clogged main jets, etc. Link to comment Share on other sites More sharing options...
Pebcak Posted January 20, 2018 Author Share Posted January 20, 2018 Adding an 8oz bottle of alcohol to a tank of fuel that already has 12.8oz *per gallon*(10%) is very unlikely to do anything.Back in the day adding drygas allowed a polar solvent to be miscable in a non-polar solvent, because it will mix with both.You either have a fuel restriction or an ignition that is breaking down at higher rpms.Figure a way to determine if your miss is load or rpm dependant.Drive in a lower gear on flat ground for a few miles. Drive in a high gear up a long hill.Do either of these cause it to happen, or be worse?"It's totally random when it happens"is not a valid conclusion.SOMETHING causes it to happen...I never thought of hills while driving. To clarify, I'm NW of Dallas. No hills for me to drive where I go to and from work. It's pretty level with fields. When it does happen it's when I'm in the 50's trying to get up to anywhere from 55-70 with the two roads I'll attempt to drive on after work or on weekends. When I say random I meant that I could be on the same road going 60 one time and the next time; hours, days or weeks later I can't go over 45 without it losing power. With the replies that've been posted I'm going to look at the carburetor and see what I can figure out. On Sat, Jan 20, 2018, 06:49 ArdWrknTrk [via Bullnose Enthusiasts] <redacted_email_address> wrote: Link to comment Share on other sites More sharing options...
Pebcak Posted January 20, 2018 Author Share Posted January 20, 2018 Fuel delivery is extremely important with a fuel injected engine. There is no extra fuel ready, like in the bowl of a carburetor. If this only happened after WOT situations, a moment after being in WOT, I could see it being a fuel delivery issue. But there is enough fuel in the bowl to allow you a couple miles in most instances. So if this happens as soon as you reach over 45mph . .its not delivery, at least not outside the carb. Fuel delivery inside. absolutely. Low level, clogged main jets, etc.Thanks for the insight! I'm still new to troubleshooting fuel delivery and carburetors. I know basics still. Tank, lines, fuel filter and what a carburetor is. :) It's hard to find anyone in person that can physically show me things. Guess I need to make sure I make it up to the next Oklahoma meet!! On Sat, Jan 20, 2018, 10:55 PetesPonies [via Bullnose Enthusiasts] <redacted_email_address> wrote: Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted January 20, 2018 Share Posted January 20, 2018 I apologize. Did not realize how flat it is where you are. That it only happens *sometimes* makes it more challenging to diagnose. Are you sure it is fuel and not something like a sticking advance plate in the bottom of the distributor? It would be great if you could make it up to Skiatook for a GTG. Plenty of projects and knowledge to share at Gary's Garagemahal. Link to comment Share on other sites More sharing options...
Pebcak Posted January 20, 2018 Author Share Posted January 20, 2018 I apologize. Did not realize how flat it is where you are. That it only happens *sometimes* makes it more challenging to diagnose. Are you sure it is fuel and not something like a sticking advance plate in the bottom of the distributor? It would be great if you could make it up to Skiatook for a GTG. Plenty of projects and knowledge to share at Gary's Garagemahal. Sticking the what, where with who? I'll need to look that up. Ha! I'm serious when I say I have no clue. But, I'm willing to learn is the point! Just please bear with me is all I ask. On Sat, Jan 20, 2018, 13:02 ArdWrknTrk [via Bullnose Enthusiasts] < ml+s12971n6278h49@n8.nabble.com> wrote: > I apologize. > Did not realize how flat it is where you are. > > That it only happens *sometimes* makes it more challenging to diagnose. > Are you sure it is fuel and not something like a sticking advance plate in > the bottom of the distributor? > > It would be great if you could make it up to Skiatook for a GTG. > Plenty of projects and knowledge to share at Gary's Garagemahal. > Lil' Red > '87 F250, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with an > Edelbrock 1826 and Performer intake. > Too much other stuff to mention. > > > ------------------------------ > If you reply to this email, your message will be added to the discussion > below: > http://forum.garysgaragemahal.com/Fuel-lines-tp6246p6278.html > To unsubscribe from Fuel lines, click here > > . > NAML > > Link to comment Share on other sites More sharing options...
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