[Gator67]

I replaced the fuel pumps on two of my cars in January (Delphi MF0154 on my 68 Firebird, Delphi MF0100 on my 67 GTO) and neither lasted 100 miles. The former just died while idling in my garage...it doesn't pump any fuel at all. The latter just delivers weak spurts. I've replaced both pumps roughly 2 years ago as well for similar issues. Are there any good options for mechanical fuel pumps these days? I've set-up high quality fuel systems for our fuel injected pro-touring cars, but really wanted to keep these cars simple and factory appearing.

[moneypit]

I've had good luck with the Carter high performance mechanical pump. I run one on my 467 with dual Edelbrock 750's. 3/8" line, inline filter between tank and pump and pump to carbs.

[nUcLeArEnVoY]

I just use a Carter stock replacement pump for my W72 400 and it's been fine after 5+ years. If I recall from when I tested it; it puts out like 8.0-9.0 PSI of pressure. That happens to be right in line with the spec per the service manual. The later 70's Qjets with the smaller nitrophyl floats ran under higher pressures.

[JBanna]

I use a Carter Street pump on my 78, and it seems to do the trick ...

[srmmmm]

I am running an Edelbrock Performer mechanical pump. No issues in 2600 miles over the course of 18 months. 110 gph with an internal regulated 6 psi.

[steve25]

So many of what you call pump failures in about a two
Year span leads me to believe you have other issues going on in both of those cars, like the the pumps are sucking air .

[JLMounce]

Agree with Steve on this. If they are failing repeatedly and that quickly, I'd be looking for a downstream cause.

How old are the fuel lines? When was the last time the sock on the sending units was changed? Those original socks, or socks from as late as the early 90's can become brittle and cause a starvation issue when E10 fuel is being used.

[P@blo]

Been through this on a few of my cars. Start by replacing the fuel tank and sending unit, then work your way through the lines if necessary. No issues with Delphi big can pumps here either.

[Gator67]

Installed a new tank and new fuel lines in the goat about 15 years ago. I replaced the sending unit two years ago along with all the rubber hoses when the first pump failed. Essentially the same deal with the Firebird, although the tank and lines are a few years newer. I'll replace the lines again I guess, along with the socks. I ran a camera down both tanks and they look pristine.

[65 Lamnas]

Originally Posted by Gator67

I replaced the fuel pumps on two of my cars in January (Delphi MF0154 on my 68 Firebird, Delphi MF0100 on my 67 GTO) and neither lasted 100 miles. The former just died while idling in my garage...it doesn't pump any fuel at all. The latter just delivers weak spurts. I've replaced both pumps roughly 2 years ago as well for similar issues. Are there any good options for mechanical fuel pumps these days? I've set-up high quality fuel systems for our fuel injected pro-touring cars, but really wanted to keep these cars simple and factory appearing.

I haven't tried their fuel pumps, but I've been VERY impressed with everything I've bought from RobbMc. I think they offer 2 different mechanical pumps for our Pontiacs.

https://www.robbmcperformance.com/pr...ontiac550.html
https://www.robbmcperformance.com/pr...ntiac1100.html

I saw your desire to keep it "factory appearing", and these 2 pumps probably aren't, but the other suggestion would be to keep an eye out for an NOS AC-Delco pump on marketplace or E-Rape.....

[steve25]

Keep in mind that new everything does not guarantee that the clamps on any hose to steel line connection points are as tight as they need to be.

Many times I have seen a air suction point yet no discernible fuel leak.

[HWYSTR455]

Keep telling everyone, just go electric, 1/2" hard lines as much as you can, leave little rubber as possible, AN connectors, bypass regulator, in tank pump.

I went through this years ago and bailed, never looking back. Been very successful results, same with many others.

As more and more cars go efi, it's only going to get worse. And replacements will become 'specialty' items with the prices skyrocketing. It's actually surprising mech pumps are still being made, the only requirements still in place is like 7 years, manufacturers are going to dump the mech pumps soon, there's no money in it.

If you want the OE look, gut a mech pump and just run a line thru it, hide the regulator. If you're not showing the car in a judging circuit, it doesn't matter, you're just being stubborn.


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[68bird400HO]

I had fuel pump issues a few years ago and started a thread on it. I had replaced my leaking fuel pump and the new one died after about 100 miles. I did find the reason for the pump failure and started discussing it at about post #58. Here is a link to the thread at page 3.

https://forums.maxperformanceinc.com...=868529&page=3

In short, the failure isn't the diaphragm, it is the arm. The repops are using the wrong arm. It appears the repops copy the Delco body but are using the Carter arm which is a little different and sits a little higher at the eccentric contact point. This puts too much pressure on the arm when compressed and they eventually break, and the car dies instantly. There are some out there with the correct arm, the "Muscle Car Fuel Pumps" from Summit or Jegs but I am not sure if they are produced anymore.

You also could try to buy a repop and swap the arm. I was messing with that a little and just don't have the correct tool to uncrimp the aluminum to get the arm pin free. I think it would slide out if you could do that, though.

[HWYSTR455]

I've seen the roll pin come out of the arms before, maybe that's because the arm was under too much pressure from being the wrong arm, dunno, but makes sense.


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[Skippy597]

I've been really impressed by robbmc products so I just ordered his 550 pump, a filter and regulator for my 460 build. Already have his 1/2" pickup and his large 100 micron filter plumbed. I expect no issues.

[Shiny]

Originally Posted by 68bird400HO

I had fuel pump issues a few years ago and started a thread on it. I had replaced my leaking fuel pump and the new one died after about 100 miles. I did find the reason for the pump failure and started discussing it at about post #58. Here is a link to the thread at page 3.

https://forums.maxperformanceinc.com...=868529&page=3

In short, the failure isn't the diaphragm, it is the arm. The repops are using the wrong arm. It appears the repops copy the Delco body but are using the Carter arm which is a little different and sits a little higher at the eccentric contact point. This puts too much pressure on the arm when compressed and they eventually break, and the car dies instantly. There are some out there with the correct arm, the "Muscle Car Fuel Pumps" from Summit or Jegs but I am not sure if they are produced anymore.

You also could try to buy a repop and swap the arm. I was messing with that a little and just don't have the correct tool to uncrimp the aluminum to get the arm pin free. I think it would slide out if you could do that, though.

I remember seeing this post and it didn't sink in.

Thanks for bringing this up again!


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So when I installed a Delphi pump that had low enough pressure to avoid overpowering my carb inlet, I may have also sentenced it to a short life?

Hmmm.... I will have to check this!

Do you know if the difference in arm geometry affects the pump stroke?

If so, I now wonder if these new aftermarket pumps have reduced pump volume because of the "wrong" arm? If so, maybe this contributed to the amount of cranking I experienced to fill my carb when the bowl was dry?

I kind of doubt it because of the flow ratings but it's a thought....

Mike

[Formulajones]

Originally Posted by Gator67

I replaced the fuel pumps on two of my cars in January (Delphi MF0154 on my 68 Firebird, Delphi MF0100 on my 67 GTO) and neither lasted 100 miles. The former just died while idling in my garage...it doesn't pump any fuel at all. The latter just delivers weak spurts. I've replaced both pumps roughly 2 years ago as well for similar issues. Are there any good options for mechanical fuel pumps these days? I've set-up high quality fuel systems for our fuel injected pro-touring cars, but really wanted to keep these cars simple and factory appearing.

I've had the same issues on the same day with 2 new pumps from Napa. One died close to the house and took that one back. They warrantied it for another and it goes about 4 miles from the house and dies. Napa just gave me my money back at that point. I ordered a different brand pump and put that on, it's been fine for 3 years. Over that period I dealt with this same issue on another car lol

I've come to the conclusion these store pumps from airtek, carter, AC it doesn't seem to matter, they are hit and miss. Sometimes you get a good one and sometimes you don't. Sometimes you get 2 bad ones in a row on the same day like I did lol

So anymore if I want mechanical I do one of 2 things. I'll either buy robbmc as they have been nice pumps that are rebuildable, or I'll buy one of summits high output pumps, like a 90gph or something similar (doesn't require a regulator) and those have been rock solid for me.

If I'm not buying those then I'm sticking a walbro in the tank,....done. there are no other options as far as I'm concerned anymore when it comes to fuel systems.

[Formulajones]

If you like the reliability of the intank setups but also want stock appearances. You can put the pump back on the engine and even run a fake fuel line.

I did that on my Chevelle when I went efi. Ran the dummy pump and factory steel line up to the throttle body that was soldered shut. Fooled everyone that looked at it LOL

[68bird400HO]

Originally Posted by Shiny

I remember seeing this post and it didn't sink in.

Thanks for bringing this up again!


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So when I installed a Delphi pump that had low enough pressure to avoid overpowering my carb inlet, I may have also sentenced it to a short life?

Hmmm.... I will have to check this!

Do you know if the difference in arm geometry affects the pump stroke?

If so, I now wonder if these new aftermarket pumps have reduced pump volume because of the "wrong" arm? If so, maybe this contributed to the amount of cranking I experienced to fill my carb when the bowl was dry?

I kind of doubt it because of the flow ratings but it's a thought....

Mike

I don't think the arm difference affects the flow or volume. My bird was running the same as with the old pump for the 100 miles that the new pump lasted.

[carcrazy]

I'd give another vote for RobbMc....excellent products and support.