7.3 IDI lift pump questions

Replace the mechanical lift pump or not

  • Yes! Swap is worth it.

    Votes: 2 28.6%
  • Nope yours is doing fine

    Votes: 5 71.4%

  • Total voters
    7

Caleb M Hughes

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So my 94 IDI has been dumping oil from the lift pump gasket so it's next to get repaired, while I have the pump off is it worth the 25 dollars to replace the pump or should I just continue to use the one I have, I'm not converting to an electric pump. I'm just not sure if the pump is a wear item or if it's a either it works or it doesn't type item.
 

Booyah45828

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I typically have a half a tube of silicone sealant laying in the tool box from another job. So if it was mine, I'd just pop the old pump out far enough to clean the grease and oil off, then put some silicone on the surface, and bolt it back up.
 

chillman88

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I wouldn't replace it if you're buying a $25 pump, you'll be putting your old one back on in a few months when the cheap one pukes out on the side of the road. Been there done that.

Either replace it with a Motorcraft pump or just reseal and go.
 

Cubey

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EDIT: I need to brush up on my reading comp. I thought the question was "should I go electric?"

If you hate working in confined spaces trying to install something just so (ie: the arm under the cam), I'd convert to electric. It gives you instant priming/air purging if you change fuel hoses or filters.

It cost me close to $200 to convert my RV to a Holley Red pump. Almost half the cost was brass fuel line fittings, electrical fittings, wire, a bag of clamps, etc. But on a van chassis, it's VERY hard to reach the lift pump. I would have dread having to install a mechanical pump to a van chassis.

https://www.oilburners.net/threads/...electric-fuel-pump.87176/page-10#post-1048900

On trucks, it looks less bad.
 

IDIBRONCO

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The thing about reusing the mechanical lift pump is that if it's an older pump, a lot of times it fails soon afterward. I was told that it lets the diaphram extend farther than it has is a long time. this causes it to weaken and fail. I won't guess as to the accuracy of that, but I can say that it appears to be pretty close. At the shop I used to work at, we used to give customers the option to reuse their lift pumps. The ones that were reused did seem to fail at a fairly high percentage. of course the customer would want us to cover it under warranty. The boss finally got tired of that so he decided that there was no longer a choice. If we installed an engine, it got a new lift pump. Problem solved. It's your choice, but I think I would install a new one. Otherwise you could be doing the same twice.
 

BeastMaster

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I like my electric fuel pump as it makes it so much easier to prime the fuel system after filter service or accidental run out of fuel situations. Also I feel a lot more comfortable in fuel system troubleshooting as for many issues, I don't have to have the engine actually running in order to verify fuel is being delivered. Saves a lot of work for the starter motor and batteries.

As a bonus, mine is a bit noisy and I can hear it whining while awaiting the glow plug heating cycle to complete. The whine changes pitch when I am good to initiate start.

The downside to me is should it fail during engine run, I fear the IP may suck hard enough to get enough fuel to inject, but there won't be any oversupply for coolant for the IP, with subsequent cooking of the IP. Anyone know if the IP will just suck air up the return line and just shut down the engine with no harm done?
 

Cubey

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The downside to me is should it fail during engine run, I fear the IP may suck hard enough to get enough fuel to inject, but there won't be any oversupply for coolant for the IP, with subsequent cooking of the IP. Anyone know if the IP will just suck air up the return line and just shut down the engine with no harm done?

Use a good quality pump and I doubt that would happen. An electronic fuel pressure gauge so the gauge can be inside could help relieve you of that concern. Holley has a 1yr warranty if you register it, and repair kits are about $25 so you can rebuild it on the side of the road in a short amount of time. That's why I went with Holley Red in my RV that is my full time home and vehicle.

People have reported that they turned off their epump and the engine kept going, so...
 

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