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Re: Heat Soak Problems Got around to removing the fuel filter to replace it. I blew through it, and it's not plugged. And I looked at the gasoline coming out of the supply line when cycling the pump. The new filter I put on a few months back helped due to less resistance. But it's become apparent that the stinkin' pump is getting worse. So, it's time for a new pump I guess I have to make a 160 mile round trip tomorrow. I hope the damn thing doesn't leave me walking. I'm on K'kins AAA plan, so they'll come out and put the truck on a rollback to get it home if it pukes............but I have to leave the trailer on the side of the road. Which means I might as well say goodbye to the trailer. I'm not sure if a regular truck wrecker could pull the whole thing home.........I imagine they can......but the cost is gonna be prohibitive.
Re: Heat Soak Problems
Re: Heat Soak Problems Truck made it to the house last Wed., and promptly died in the driveway while I got out and unlocked the gate. It appears that the fuel filter is plugged again I think the aluminized crap they make the tanks out of, has rusted from water in the gas, and the crap is getting sucked into the filter. I'm gonna see if I can fit the plastic tanks in the truck that later trucks had............probably mean a new fuel pump to fit those tanks too And some sorta new mounts I had this happen with the behind the seat tank on the old 78 Powerwagon. I just quit using that tank, and only ran off the plastic in frame tank for about 10yrs. Metal tanks SUCK!!!!!!!!!!!!!!!!!!!!!!!!!!
Re: Heat Soak Problems Originally Posted by Zimm Thats the next thing to try if the fancy sockets don't work. The 13/16 version was a little too big to fit in the cavity so I took some metal off with the lathe. It didn't get a good grip. Next up is 19MM and 17MM. Damn thing is really stuck- i was pulling pretty hard on a breaker bar. That doesn't work, big nut and 6011 as above. Worry there is some of the porcelain could end up in the combustion chamber. We will see. Worst case is pull the head. To follow up on this bit of thread hijack: Ended up pulling the stinkin head. Engine is back together and running OK now and its time to move onto the fuel feed issue. For you pull/no pull the bed fans: Got it off with little trouble. Soaked the bolts (dome head, not torx) with PB Blaster over a week or so and went after them with an impact at about 120 psi. Damn things were 18mm. Used a 6 or 12 inch extension as needed and a stout knuckle and they came off just fine. Its sitting on my two post as this is written. Tomorrow I will scope things out. Lots of crusty lines under that bed. Sure is nice to be able to stand up with it all in front of me.
Re: Heat Soak Problems Originally Posted by farmersammm Only two pages. I must be slipping in my old age Well the good news is by the time you get the sending unit problem from the front tank, and the problem with not getting gas from the back tank you will probably be over four pages at least
Re: Heat Soak Problems Time to drop the tank and pull out the sending unit. There is a place out there somewhere that rebuilds them Can’t remember the name right now.
Re: Heat Soak Problems I figure I'm ok doing that because I always carry the cellphone. I never go far from home, so it's not too bad. I figure if I run out of gas, I can call K'kins to run me some gas, or take me to the station. Usually when I call during the day....................."What have you done now?" I mean..........she doesn't even let me start my speech, she just heaves a big sigh, and says that. I like to surprise her once in a while, and tell her that I called just to say hello, and "luv ya babe".
Re: Heat Soak Problems Originally Posted by gnewby Well farmersammm I don't think you have completed this thread as yet as we haven't heard an update on the F150 I'm still running the F-150 on the front tank. Sucky thing is........the gauge doesn't work on the front tank, so I use the trip meter thing on the speedo when I fill it.............then watch the # of miles since the fill
Re: Heat Soak Problems Originally Posted by farmersammm Only two pages. I must be slipping in my old age Well farmersammm I don't think you have completed this thread as yet as we haven't heard an update on the F150
Re: Heat Soak Problems Originally Posted by Zimm I hear you, but if the bolts come out, my two post friend can pick that bed up no problem. See how it goes. Its all fixable, just a matter of how much trouble its going to be. Just so you know, the bed bolts ARE NOT torx! They are torx plus! If you use regular torx on them you will more than likely strip out at least 2 and have to cut the heads off! Ask me how I know! https://en.wikipedia.org/wiki/Torx#:...%20loose%20fit.
Re: Heat Soak Problems Originally Posted by ronsii You might think about cutting a panel in the bed to give access then depending on how/where you cut it weld a frame under(like a drywall repair) or just bolt it back in. personally I usually just drop the tanks... kind of a PITA but simpler than lifting the whole bed I hear you, but if the bolts come out, my two post friend can pick that bed up no problem. See how it goes. Its all fixable, just a matter of how much trouble its going to be.
Re: Heat Soak Problems Originally Posted by Willie B "Any ideas for how to get that plug out would be welcome." If you can get around it, slip a very large nut over it. MIG it to the steel. If you can't make room, break off the porcelain. Slip an impact socket over it, and weld it to it with 6011 filler. The heat from welding might help, but be careful not to get the head too hot. It'll take a tremendous lever of patience wiggling the socket back & forth, I think it'll loosen. Friday I had two grade 2? bolts rusted solid in the end of two shafts, and broke off 1/4" deep. Only welder I had was MIG. With patience I built up flush, then a good sized ball of filler sticking out. It took 15 minutes each of wiggling with vice grips to free the thread. One of the two was bent halfway through the thread. Thats the next thing to try if the fancy sockets don't work. The 13/16 version was a little too big to fit in the cavity so I took some metal off with the lathe. It didn't get a good grip. Next up is 19MM and 17MM. Damn thing is really stuck- i was pulling pretty hard on a breaker bar. That doesn't work, big nut and 6011 as above. Worry there is some of the porcelain could end up in the combustion chamber. We will see. Worst case is pull the head.
Re: Heat Soak Problems Originally Posted by Zimm Yeah. I was under it yesterday looking at the bed bolts. They don't look too rusty. Going to start soaking them with PB Blaster. I like the idea of pulling the bed to be able to get to everything from the top. Pulling those tanks out is a PITA. Got other stuff to do on that truck after all these years too. The #1 plug is rusted and rounded. Not good. I ordered a couple of special sockets from SK to see if I can get it out without pulling the head. It runs OK, but is overdue for an ignition tune up. The other 5 loosened up fine. After that, pan gasket, rear trans seal leaks, brakes. After 195K, its time to catch up on stuff. Any ideas for how to get that plug out would be welcome. You might think about cutting a panel in the bed to give access then depending on how/where you cut it weld a frame under(like a drywall repair) or just bolt it back in. personally I usually just drop the tanks... kind of a PITA but simpler than lifting the whole bed
Re: Heat Soak Problems "Any ideas for how to get that plug out would be welcome." If you can get around it, slip a very large nut over it. MIG it to the steel. If you can't make room, break off the porcelain. Slip an impact socket over it, and weld it to it with 6011 filler. The heat from welding might help, but be careful not to get the head too hot. It'll take a tremendous lever of patience wiggling the socket back & forth, I think it'll loosen. Friday I had two grade 2? bolts rusted solid in the end of two shafts, and broke off 1/4" deep. Only welder I had was MIG. With patience I built up flush, then a good sized ball of filler sticking out. It took 15 minutes each of wiggling with vice grips to free the thread. One of the two was bent halfway through the thread.
Re: Heat Soak Problems Might be the same sockets you ordered. Anyways, I thought this was a good idea. I've never seen these before.
Re: Heat Soak Problems Originally Posted by ronsii Sounds like the common issue with the multi tank fords the check valve on the fuel pump assemblies goes bad and let the other pump feed back into the bad pump(tank)... symptoms are low fuel pressure on one or both tanks, slugishness, running rich,etc.... Fix: replace the bad fuel pump/s or some people have actually put in secondary check valves... Yeah. I was under it yesterday looking at the bed bolts. They don't look too rusty. Going to start soaking them with PB Blaster. I like the idea of pulling the bed to be able to get to everything from the top. Pulling those tanks out is a PITA. Got other stuff to do on that truck after all these years too. The #1 plug is rusted and rounded. Not good. I ordered a couple of special sockets from SK to see if I can get it out without pulling the head. It runs OK, but is overdue for an ignition tune up. The other 5 loosened up fine. After that, pan gasket, rear trans seal leaks, brakes. After 195K, its time to catch up on stuff. Any ideas for how to get that plug out would be welcome.
Re: Heat Soak Problems When it was a couple years old, my 2001 Savana van had the 4 wheel drive conversion. The fuel pump cut out regularly. Took it to the dealer several times for fix. They said it wouldn't act up for them. I needed the truck, so I added key on power source controlled by a manual switch. Mr. Goodwrench kept removing my added wiring. I got mad, said if you can fix it so it doesn't quit on the road, go ahead and remove my extras. Otherwise LEAVE it there! I drove it that way a few more years. Eventually the gas tank leaked. In all the wrestling installing a new tank, we discovered a mating plug in the wiring harness above the transfer case. Because the transfer case is not original, the harness was stretched.
Re: Heat Soak Problems Originally Posted by Zimm Glad thats fixed, now you can get onto the pickup. Looking forward to what you find there. I have the same issue- low pressure from the rear tank but not the front. First thought was the pump, but a new one didn't fix it. It will run along at part throttle, but lay down when more power is needed. Front tank runs fine. From what I read, there is a check valve in the system that could be bleeding off pressure. More diagnostics needed here too. Sounds like the common issue with the multi tank fords the check valve on the fuel pump assemblies goes bad and let the other pump feed back into the bad pump(tank)... symptoms are low fuel pressure on one or both tanks, slugishness, running rich,etc.... Fix: replace the bad fuel pump/s or some people have actually put in secondary check valves...
Re: Heat Soak Problems Glad thats fixed, now you can get onto the pickup. Looking forward to what you find there. I have the same issue- low pressure from the rear tank but not the front. First thought was the pump, but a new one didn't fix it. It will run along at part throttle, but lay down when more power is needed. Front tank runs fine. From what I read, there is a check valve in the system that could be bleeding off pressure. More diagnostics needed here too.
Re: Heat Soak Problems Originally Posted by farmersammm Only two pages. I must be slipping in my old age Happy to hear you got her done. Sincerely, William McCormick
Re: Heat Soak Problems Only two pages. I must be slipping in my old age
Re: Heat Soak Problems Attachment 1719646 Put about 40 miles on it this evening, and no problems Gas mileage is back to normal...........it took about 7.5 gallons to make the trip. Power was pretty good..........70mph when needed. No hesitation, and NO STINKIN' VAPOR LOCK WHEN IT GOT HOT ON THE WAY BACK I'd like to see another 5lbs on the snap, but it's running well...................so for now, it's good to go. The fuel filter was the culprit. And......if I ever find the time, I'd like to drop the tank, clean it out, and put a new strainer on the pump. I guess it seemed like a long drawn out process, but mostly the time was used to learn how to use the scope. I've never had to do actual voltage measurements on the thing in all the years I've owned it. Knowing what I know now, it really boils down to about a 15 minute total test including pressure, and amp ramping. This was the first fuel problem I've had on any of my 1994's. I guess it says a lot for that particular year. Would I just guess, and slap a filter on it?????? Y'all know me It has to be a right diagnosis before I do anything. I hate throwing parts at a problem It's a real pleasure to have it back up and running again. There isn't a modern gasser that will out pull these old 460's. I get a kick out of flyin' by them on a four lane
Re: Heat Soak Problems Originally Posted by solman What's the year model and make of the truck? What engine is in it? Have you eliminated the basics such as fuel filter and basic tune up? It does sound like fuel starvation problem which can be a clogged filter or screen in the tank on the fuel pickup. After the truck Sits a while the clog eases somewhat as there is no longer any pressure on the filter and it will run again for a while. Just a thought and easy enough to do the filter for a few bucks. Also check for a restricted exhaust system problem. You might be in the ballpark, but with a twist. This truck has a constant problem. The fuel tank gets water in it when it rains. Not all the time, just when the drain in the filler neck well gets plugged. This truck has the neck set up so you fill the tank from the TOP of the bed. Stupid design, but it is what it is. Debris plugs the little hole at the bottom of the well. I keep meaining to hog the hole out, but never get around to it. Water fills the well, and it gets in through the filler cap. When this happens, I have to pump the water out through the Shrader valve on the fuel rail. There's no way to siphon the tank through the filler neck. Something blocks the siphon hose from entering the tank.........it only goes in as far as the filler hose between filler neck, and tank.........and won't go in the rest of the way. Last time I did this, the fuel just dribbled out..........not a good full flow. I thought I plainly addressed the specs for this system in the video, but maybe folks missed it. Attachment 1719595 7.5l should run 30 at idle, and up to 45 under load, or at throttle snap. I get 30 at idle, but only go to 36 at throttle snap. What I said, and illustrated, in the video........along with saying I'd like see it go higher at the snap. The pressure never drops below 30 at any time in the "shop", but I have no idea what it's doing on the road when it gets extremely hot under the hood, and possibly the fuel pump gets hot. Tests have confirmed that it does draw 1amp higher when it runs in the shop for an extended period. Dunno what the draw is when it's actually running under load with different demand, and heat. I've suspected vapor lock since the beginning, and I'm still pretty much convinced it's happening If that fuel pressure drops below 15 when the truck is hot, the fuel will boil. When it cools, the problem will resolve itself. This problem only occurs after pulling heavy. Always on the return trip when the truck is loaded. I replaced the filter a couple of drain cycles ago, but that's been a while. Probably had to drain the tank at least twice since then. It's possible that the water has started to rust the tank, and crud has been sucked into the filter.........OR MORE LIKELY BLOCKED THE STRAINER ON THE PUMP. This would cause a flow issue. If flow is decreased, pressure will decrease down the line under high demand. Static pressure won't be affected. But, because this is an older "return" system, pressure could be taking a hit all the time, although it's pretty close to spec at idle, and never drops below 30 on a throttle snap. I'd suspect poor power, as I've experienced for about a year now, but I wouldn't expect a shutdown unless the pressure is actually dropping close to 15 when hot. 15 won't result in a no start, but it could result in a vapor lock situation. So, now that I've figured out what I'm seeing on the scope, the next step is to look for restrictions in the fuel line, or pump intake. I'm not totally ready to condemn the pump.
Re: Heat Soak Problems This has been a really difficult learning curve, and I've spread some misinformation.........I apologize After watching literally hours of YouTube videos, and trying to understand manuals written for someone who ACTUALLY has a clue................I finally got it. WHEW!! The basic screen has a BASELINE. It's labeled "A". The divisions ABOVE AND BELOW that baseline are volts, millivolts, and microvolts.........depending on how you set the scope up. Attachment 1719579 This is the default location for the baseline. Always in the middle. Attachment 1719580 You can reposition the baseline if you need to measure volts in excess of half the horizontal divisions on the screen. In this example, each division has been set to represent 5V (A:5V lower left hand corner). I can measure a signal up to 35 volts now, because I have 7 divisions above the baseline. The screen shows a flat solid line on A (baseline). This is because no voltage is being measured. This is 0 If I were to measure a constant DC signal, the solid black line would move ABOVE the baseline (A) in divisions corresponding to the amount of voltage I'm measuring. Now, let's look at what was actually measured on the truck (sorry about the glare, and poor photos) Attachment 1719581 This is looking at the Graphing Multimeter. The solid line is one division above the baseline, plus a tad. Now look directly below the divisions. The number second from the left identifies what each division represents. In this case..........each division is 5amps (5A/d). The digital display in the upper left shows the amperage (5.88). This corresponds with the location of the solid line on the grid above the baseline. You can see the line is about 1/5 the distance into the next division. Attachment 1719583 (Before we go onto the scope, you might be wondering why the solid line doesn't show any waveform.....it's because the minimum time division on the GMM is 5 seconds, and the variation in amps is too small for the scale on the GMM). Now let's see how it looks on the scope. Attachment 1719584 This is current ramping the fuel pump. Measuring same thing as the GMM, but now we can see the current build between the commutator bars on the motor as it spins. From low amperage to max amperage on each wave. The baseline is at A. There are 7 divisions above A. Looking directly underneath the graph, you see what each division represents (A:0.1V). Each division is 1/10 volt, or 100 milliamperes. Our highest peak on the wave is a tad above the 6th division, or 600mA The amp probe is set at ImV/10mA. This means that we multiply the 600mA reading by 10, which gives us 6000mA, or around 6amps. Thus, the oscilliscope agrees with the Graphing Multimeter (GMM) Next, we have to interpret the peaks and valleys in the oscilliscope pattern. Each peak is the max amp draw as the motor spins. The valleys are the lowest amps drawn as the motor spins. You're never going to get back down to the baseline if the brush/commutator are passing current as they interact. The only time you'll get down to the baseline is if you have a "dead" commutator (this is where you have to bang on the gas tank to get the pump going again). So, the pump in the truck is drawing 6amps peak, and 5amps minimum, as it spins. It's not suffering from a dead spot.
Re: Heat Soak Problems What's the year model and make of the truck? What engine is in it? Have you eliminated the basics such as fuel filter and basic tune up? It does sound like fuel starvation problem which can be a clogged filter or screen in the tank on the fuel pickup. After the truck Sits a while the clog eases somewhat as there is no longer any pressure on the filter and it will run again for a while. Just a thought and easy enough to do the filter for a few bucks. Also check for a restricted exhaust system problem.
Re: Heat Soak Problems I got 'er fingered out!! The Hantek low amp probe is different from those mostly used for automotive stuff, but it's same same (sorta). Attachment 1719488 This probe has two settings. 1Mv = 10Ma...........and 1Mv = 100Ma We know that 1000Ma = 1amp Attachment 1719489 My voltage range is 50Mv per division on the vertical axis. My time is 2Ms per division So..............................we gots approximately 150Mv output from the probe. 150Mv x 10Ma = 1500Ma 1500Ma / 1000Ma = 1.5amps The pump is TOAST . Or there's excessive resistance in the circuit. Or my calculations are wrong Now why the graphing multimeter function gave a bad result (amps too high compared to scope), I dunno (shrug) I don't fully understand this aspect yet.
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