# 7.3L IDI Finding lift pump problem



## AmateurSawer (Jan 15, 2020)

My 7.3 IDI lift pump in my 93 Ford went bad.
Got one from NAPA but the mechanic said the armature was too long compared to the old one.Checked with NAPA and they gave me the part their book calls for.Federated didn't match,either.
I am beginning to think someone put the wrong pump on once before and just got by.I know I can get one from a dealer but at twice the price.
Any experience or suggestions would be helpful. Thanks.


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## dgr (Feb 13, 2020)

That's the way they are. Last one I bought has a paper insert. This one (drawing of new one) replaces this one ( drawing of old one). Make sure you get the arm under the cam or you'll be buying a new pump. 

Make sure your mechanic replaces any olives (vibralock seals) that he had to disturb like the one at the top of the hardline from the pump to the filter housing. He can get them from McMaster or from a tractor dealer. 3/8 and 5/16 are the sizes for an idi. 

He should also replace the short piece of fuel line between the frame rail and the lift pump. It should be a complete loop,not a straight piece. 

You can install a clear hose between the return caps and the fuel filter housing to look for air intrusion. That'll make it hard to start or start and die in the morning. You should be on oilburners. net forum.


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## AmateurSawer (Feb 14, 2020)

dgr said:


> That's the way they are. Last one I bought has a paper insert. This one (drawing of new one) replaces this one ( drawing of old one). Make sure you get the arm under the cam or you'll be buying a new pump.
> 
> Make sure your mechanic replaces any olives (vibralock seals) that he had to disturb like the one at the top of the hardline from the pump to the filter housing. He can get them from McMaster or from a tractor dealer. 3/8 and 5/16 are the sizes for an idi.
> 
> ...



Thanks. Got the right pump and mechanic fixed the lines,too. Running great again.


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## dgr (Feb 14, 2020)

AmateurSawer said:


> Thanks. Got the right pump and mechanic fixed the lines,too. Running great again.



Glad to hear it. If your truck doesn't burn oil, you should still check it regularly (this applies to most engines with a mechanical fuel pump). One of the _rare_ failures is the diaphragm to fail where it fuel islowly pumps furl into the crankcase.

Love my 86


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