Ok, stats:

1975 F250 with a 360 engine.

We have a few updates and things we need to figure out.

Update with our fuel pump problem? We said heck with it and I installed an electric fuel pump, and we put a blocker plate over the fuel pump spot on the engine. Found a total complete disaster under the truck regarding fuel hoses. Due to the electric fuel pump just 'knocking' and not pumping? We installed a temp fuel steel line from the pump unit to the mid-ship connector. (aka where the fuel tank selector is found and hooked up) Before anyone asks? This ol' girl has dual tanks under the truck bed. The rear tank is being used, the front tank is questionable. Now I have a gut feeling the fuel pump might not quite cut it for the long term--It just makes the grade for flow and pressure--but it's got a long trip to the carb. So that might get upgraded to a slightly larger unit in the future. But it was great to hear the carb bowl filling up when we kicked the pump 'on'. (it's now wired to an ignition 'on' connector at the fuse panel)

Ok...that's sorted out.

Next set of questions. We do not have an 'in cab' tank. We have the middle tank under the truck bed, and a rear tank. We would like to use both tanks by the time we are finished with this wing-ding. I can order in the middle tank and 'custom' fab up a pump for that tank, and a universal selector switch. But we have two major problems in replaceing it. 1) While we can get the tank? I can't find the sending unit for the middle tank?? Seems everyone has the in-cab type, or the rear mount type...but no one I can find has the middle tank one? 2) Same problem with the fuel tank straps for the middle tank---Everyone seems to have the rear mount tank straps...but I'm striking out with the straps for the middle tank?

So I'm wondering--should I just custom make a set of straps for the middle tank? (it's gonna fall apart when I remove that tank to replace it--rusted badly) Or should we just remove the middle tank completely and just leave it off? I need to do some sheet metal work on the body in that area, so I can install a plate to cover the fuel inlet.

And of course, my better half wants dual exhaust with glass packs. I found a 'kit' that is decent for price, but it states it will need to be modified if the truck has a middle fuel tank.

As you can see this is quite the project. As it stands I'll have to pull the drivers side fender to repair the rusted out section where the cab mounts to the frame. Ughhhhhh. Someone bolted a plate there to keep the cab level, and it's just not the right fix.

Any help or asprin is greatly welcome.

Best

S-

 

Topics in title please

Personally I will find the correct mechnical fuel pump to service both tanks.

How did you reduce the fuel pressure to 7 psi on the electric pump ?

Midship tank fuel sending unit ?



Blue Oval Truck Parts
68-79 Gas Tank Sending Unit - Side Mount Tank - 2WD
Part # GA-0045

http://blueovaltruckparts.com/catalo...oducts_id=9286

 

LMC truck has the middle sending unit, item # 43-4024 for 2wd and 43-4026 for 4wd with plastic tank, price 49.95 1-800-541-8525
AC/heater control unit from a duel fuel tank truck will have the switch on it.
I did not find the straps in this catalog, however you can still find donor trucks with the side tank assembly in junk yards, they seemed to be a pretty common item.
I seen 3 trucks at one of our local junk yards last week.

 

BOTP is an FTE sponsor

LMC isn't....,easy choice

I'm still looking for the fuel tank shield & straps but you will probably have to make them.

 

If you want to run dual exhaust it will be a lot easier and you will have more options if you just remove the midship tank. The DS Longtube header will dump out right in front of the tank and you will have to make a sharp turn towards the PS and then run it to the other side of the drive shaft and then run both sets of pipes down the PS between the frame rail and drive shaft (Not a lot of space). My 77 F150 only has the midships tank and I bought a dual exhaust kit from LMC that was supposed to fit these trucks with midships tanks. LMC was the only company I found that carried this type of kit, so don't get on my case for using them. Anyway the kit was not exactly a bolt in kit by any means, since I needed to totally refabricate the down pipes to make them work, but it did turn out good (see link below). If the midship tank were not there you would have many more options and it would be a much easier install.

 

The fuel pump we installed is designed for carb engines. The company we went with (FACET-aka Puralator) makes the pumps in a couple of designs for low PSI use. Judging by the sound of the pump itself, I'd have to guess it is a small piston design pump with a check valve at the end to prevent back flush. The catalog recommended the lower pressure one (6psi) and while it is working? It has to be installed within 12" of the tank. And its got a long journey to the carb. I figure that one might do better at the middle tank once we get it figured out, and the slightly larger one (8-9 PSI with a slightly higher volume) might be better at the rear tank where it's gotta push an extra 4'. Or we might find when we tune 'er up? It does the job well at higher fuel demands.

Thanks for the part number of the middle tank sending unit. I'll probably wind up fabbing up a set of straps for the middle tank, as that seems to be just about impossible to locate.

S-

Note: While I normally work with site sponsers, I also have to go with the parts supplier with the best price if it's a decent difference. Be it a local parts house, rockauto, lmc, or blue oval. If the costs are about the same? I'll use a sponser. If the cost difference is large? Then I have to go with the lowest one. This project is on a shoe string budget at best.

 

For the most part that is how I am as well.

Costs are prohibitive from stateside.
(US companies seem to go above and beyond for your own residents though.)


Only I match price with quality vs just price

Lat thing I want to do is replace a fuel pump every couple of days.

Last pump I bought was one from NAPA in 1991 .. Litle more expensive but it has worked fine for 16 .5 years now.

 

I totally agree! Quality will always bump things up a bit when judged against cost. As much as I love our local Napa? It would seem this engine uses (or used in this case) a very oddball fuel pump, that nothing matches up with. Napa ordered in 2 pumps for us just in case their catalog was in error, advance did the same with a different manu. Each one had the cam-arm for the fuel pump slightly lower then our stock one? So the cam was not pushing the arm down enough for a full stroke. I spent 2 hours the other night at Carters website (federal mougel (sp)) And I looked at each photo of each fuel pump used in every ford V8 engine from the mid 60's to the early 80's. (talk about a fuel pump education LOL) The tell tale sign according to Napa? Is a set of drilled 'holes' (not sure what they are used for) in the casting itself at the rear of the pump, about 2" above the connection lines.

I also googled and fruggled every ID number off that pump--Came up goose-eggs.

So the electric pump was the only real option. I hate using it, as I would love to keep things as stock as possible--But this one has me scratchin' my head.

S-

 

I'll scan the ford parts book for that application for you.

 

Here you go so you know what you are up against

 

So, you installed the stock pump that the parts store suggested and had a fuel gage on it and it didn't pump any psi ?

 

Well..it was worth a shot. However the fuel pump part number per Ford: D4TZ-9350A crosses over to the same fuel pump type/size/specs that we have struck out with 3 times in a row.

As from the other thread the numbers on the pump:
0-1932
4897 (casting on mount flange)
D4TE-AA

It's one of those annoying things. Everything matches up number wise? But when you compare the new pump cam-arm with the old pump cam-arm? There is a very noticeable difference in the arms height. The new pump's arm is lower then the factory one, and therefore does not give a full stroke on each rotation of the cam-shaft. This is also confirmed when I had my wife crank the ol' girl over with the lines not hooked up, and I could barely feel any "pull" or vacuum in the "IN" port which is supposed to pull fuel from the tank.

I suppose I can (ok..this would be rather annoying to do LOL) purchase the fuel pump again, bolt it on...disconnect the electric pump. (it has a 1 way check valve, so there would be zero resistance on pulling fuel from the tank, so it can remain in-line) And see if it can work with the slightly lower cam-arm?

Other then that? I'm outta ideas.

S-

 

Didn't use a fuel gauge. I primed the carb's float bowl to ensure the engine would run for a few seconds with the new pump installed. It flat out 'ran out of gas' within about 7 seconds or so. I removed the fuel line going into the filter at the carb? And it was empty. (all hoses hooked up for this test) Basically it just would not pump fuel from the tank to the carb. Now I suppose the major screwup of hoses under the cab where the fuel selector is/was could have a lot to do with it. The electric pump didn't want to do squat until I ran a direct line from the electric pump to the carb line? (as a side bar note, I did use my vacuum pump with bowl adapter at the fuel filter hose to the carb. It moved fuel enough to fill the bowl adapter with about 5" of vacuum applied. This was before I ran a direct line)

But I'd still expect some 'suction' at the pump's "in" port while cranking the engine. It was barely enough to be felt.

S-

 

Maybe the stud for the cam eccentric broke or is loose ?

 

That is possible. I've not pulled the waterpump and timing cover to inspect it. The only tell tale sign we did see? Was a heavy full wear pattern on the old pumps arm contact area. And the new pump had a very slight wear "scratch" (for lack of a better word) showing something was trying to move it up and down.

It's also possible (I'm looking at the haynes picture of it) That 'cam' looks rather like a weak link. I'm guessing it's bolted on to the end of the cam shaft just in front of the timing chain? Could that cam eccentric be perhaps just flat out worn to the point it can't do it's job all the way? And if so, is that part alone replaceable, or would that entail a replacement cam-shaft? Also is it possible to remove the upper timing cover to inspect, without removing the harmonic balancer unit?

Granted I'd love to get the factory one working again. Just wondering about the possible issues.

S-