I've got a customer that has a 79 Ford F150 302. The truck keeps eating mechanical fuel pumps. He bought one over a year ago and has replaced it, I kid you not, seven or eight times under warranty. That warranty is running out, it's not costing him much out of pocket, so much as it's been a pain in his ass. I told him it was a bad fuel tank, with 30 years worth of crap in it.
Bought a new tank, still puked a pump. Got fed up and took it to a shop here, and he put new lines under it. This last pump didn't even hardly run once on the truck. I think I sold it to him two days ago, and they just came in and exchanged it.
New lines, new filter every time, new tank. The only thing that's left is the sender. I've noticed that the arm is worn on one side more than the other. Now I don't know the age of the cam, and wouldn't rule out the eccentric lobe being worn down, however, that wouldn't cause the fuel pump to keep destroying itself would it? Sometimes they last two months, other times they last all of a week. This one was two days.
He's a genuine nice guy, and I'm more concerned with helping him get this thing straightened out than making a sale. I tried to sell him on a universal fuel pump, but he said he's got more time than money, which is understandable.
So what does the GRM braintrust think?
Do you know which part of the pump keeps failing? Same part every time?
Just out of curiosity.. you are sure it is a 302?
I'm pretty sure the diaphragm is failing. A new one I can put my thumb on the hole and it pulls, a bad one will not do squat.
If it's not a 302, what harm would putting a 302 fuel pump on a 351M or 400 motor? That thought never entered my head.
That's why I come here!
I am not sure on the v8s.. never had one apart. But I imagine they might have a different length lobe or pushrod to run the fuel pump. Might have to cross check some parts numbers
Stop buying E36 M3ty pumps.
Believe me, I figured we had gotten a bad one early, but a half dozen? He told me the main reason why he's kept doing it is because it's under warranty and doesn't cost him much to replace it.
I'd had given up on it months ago.
I'd like to know what is dying about them... diaphragm? lever? Pivot pin?
Universal electric is a great solution, but it doesn't answer the burning question.
All of the Windsors have use the same pump up through 351W. C's, all of the M's and the 400 have a different pump. Then of course the BBF and FE use their own pumps.
79 would have a Windsor if is a 302. If its a 351, it could be either a Modified or a Windsor since the crossover was 79-80. Modifieds used a Cleveland block style with a Windsor crank, so the pump would have to be an M-style to work.
Casting numbers on the block?
Interesting.
Was the timing chain replaced sometime shortly before the first fuel pump went bad?
No, I don't know anything specific. Just a stab in the dark brought forth by Curtis73's post and BoostedBrandon's post
I'm pretty sure the diaphragm is failing. A new one I can put my thumb on the hole and it pulls, a bad one will not do squat.
After multiple failure, there has to be something overlooked,
Unless it has been changed the VIN will identify the engine. Wrong pump ?
Poor quality pump. Very possible. Is it rebuilt or new ?
Even with a life time warranty, the aggravation would kill the deal for me.
I wonder if the pump eccentric is not hooked on the cam pin it could be more off center then its supposed to be this would over stroke the pump helping the diaphragm rip and might explain the wear on the arm being off center.
Well, let me know if he gets tired and wants to sell, I still miss my old $600 79 302 F150!
mad_machine wrote:
I am not sure on the v8s.. never had one apart. But I imagine they might have a different length lobe or pushrod to run the fuel pump. Might have to cross check some parts numbers
a longer pushrod would be my thought also
I double checked at work and sure enough a modified motor uses a different fuel pump. The pump itself is the same I think, but the arms are different. I think the added leverage is tearing the diaphragm. The bitch to it is that we can't disassemble a defective pump, because then the store wouldn't get credit for the defective pump. Hasn't been back in yet, so I can't provide any info further until this one comes back.
Is this a lifetime warranty pump from Advance/Auto Zone?
If so, there's your problem. Take it back, get your money and go get a good part from a NAPA. This from a former Store Manager at an Auto Zone who has seen this over and over and over.
Seems like a freak thing to have that many mechanical pumps go bad. If he's on his 7th or 8th pump, I doubt that it's the pumps that are the problem.
I saw a guy replace the fuel pump in his mid 90' Blazer 5 times before he realized it was the wiring in his truck and not the pumps.
here is an aweful thought... are you getting the right pump from advance? I had that problem with my old Hyundai Tiburon. I planned on doing the waterpump when I did the timing belt.. got the car all apart, and discovered they had sold me the wrong pump (it was for a chrysler) so I treked across the stree from work (Where I was doing the work) to napa to get the correct pump.
Taking back the wrong pump to Advance.. they pulled another one out to check.. same chrysler pump
44Dwarf wrote:
I wonder if the pump eccentric is not hooked on the cam pin it could be more off center then its supposed to be this would over stroke the pump helping the diaphragm rip and might explain the wear on the arm being off center.
My thoughts also, besides the obvious wrong pump.
mad_machine wrote:
here is an aweful thought... are you getting the right pump from advance?
This crossed my mind as well. My buddy bought a 68 Plymouth with a 440. He made it home and the fuel pump died. No worries, right? We took it off and the arm was limp, so the pushrod broke. We took it to a GOOD parts dealer and he just looked at the part number on the pump and got us a new one. The same thing happened again.
Turns out the previous owner put a Ford pump on a Chrysler 440. The bolt spacing was the same, the gasket shape was the same, but the arm was a different shape. It was depressing the plunger too far and popping the pushrod. The parts guy (who I personally know to be good) just had a momentary lapse of judgement and gave us the pump by part number instead of application.
