What does an injector pump act like when its time to replace

shawn deere

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Just got a '90 7.3 idi ats turbo a month ago
The pump is wet and the fuel milage seems to be slipping every tank full. There is something leaking on the top getting the valley wet too. I have heard of a weep hole in the ip but havnt located it yet
Have replaced valve cover gaskets and fuel return lines so far
I hate to just throw a pump on and see... it starts good, cleans up good imo. Runs ok, has major exhaust leak pre turbo. But something is leaking, and the fuel milage is slipping....
Also looks like front main is leaking. And oil cooler
 

pelky350

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Pre turbo exhaust leak can make fuel millage suffer some. Leaking fuel could be from many things on top of the engine, return lines, any connection of fuel llines, pumps can leak in a few areas also I'm not sure if they have a weep hole though. With leaking fuel means likely air intrusion to the fuel system that will cause poorly performing engine.
 

notenuftime

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When my pump went I had fuel on the valley pan, I figured it was from failing seals just from wear and tear also my fuel consumption went threw the roof.
 

03wr250f

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There is a weep hole on the ip. I have a good test pump that I keep around only for testing because of a major leak it has from the weep hole but it started and ran well. That is one of the symptoms of a failing pump. A hard start on a hot engine but good cold starts is another and so is a hard cold start but lights off on warm engine. Their are many symptoms. A pump leaking from the weep hole is typically a sign of a failing internal seal in a Ip. there are two seals on the imput shaft when one fail it starts weeping. That signals time for a rebuild.
 

shawn deere

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Its wet underneath
From where it bolts on the front clear to the injector lines on the back. Ive tightened the injector lines and it didnt make a difference.
All the injectors ts are dry now with the new return line kit though
 

Macrobb

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Paper towels is the solution:
Take a few paper towels(or blue scott towels) and fold them up into big rectangles. Stuff them into various spots on the valley pan. Drive around. Pull them out and see where they are wet and where they aren't.

It may take doing this a couple of times to narrow it down, but it works nicely. It doesn't get hot enough up on the intake to cause any issues with the paper, especially not when you are leaking fuel which ends up cooling everything down a /lot/ as it evaporates.
 
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Macrobb

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BTW, you /can/ re-seal your IP, especially the outer seals which aren't hard to do.
There is a full DB2 manual in PDF form around which details exactly how to disassemble and reassemble the pump. As long as you are careful about crud contamination, you can do it easily enough.
Re seal kit on Ebay is around $30.

Obviously, there's a chance you could break something or cause issues, so be prepared to have to get a new pump if you screw it up. But, if you can fix it, well, that's $500+ you don't have to spend.
 

shawn deere

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Paper towels is the solution:
Take a few paper towels(or blue scott towels) and fold them up into big rectangles. Stuff them into various spots on the valley pan. Drive around. Pull them out and see where they are wet and where they aren't.

It may take doing this a couple of times to narrow it down, but it works nicely. It doesn't get hot enough up on the intake to cause any issues with the paper, especially not when you are leaking fuel which ends up cooling everything down a /lot/ as it evaporates.
Good idea!!
I got real comfortable in the engine bay with a flashlight and a mirror yesterday...
 

tbrumm

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BTW, you /can/ re-seal your IP, especially the outer seals which aren't hard to do.
There is a full DB2 manual in PDF form around which details exactly how to disassemble and reassemble the pump. As long as you are careful about crud contamination, you can do it easily enough.
Re seal kit on Ebay is around $30.

Obviously, there's a chance you could break something or cause issues, so be prepared to have to get a new pump if you screw it up. But, if you can fix it, well, that's $500+ you don't have to spend.

I believe Mel at Conestoga Diesel also sells a reseal kit complete with installation instructions. If the leak is bad enough, but the truck is otherwise starting and running okay with the current IP, it might be worth a shot doing a reseal. As Macrobb says though, be ready to buy in new IP in case things go south during the reseal.
 

icanfixall

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The weep hole in near the housing the pump bolts to under the pump. Also down there on the drivers side is the advance plunger seal. Every Time the throttle is opened that forces the plunger into the bottom of the pump. That might be a leak also.
 

shawn deere

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It passed the tissue test. Discovered the PO didnt tighten the hard to get to nut under the throttle cable. Thinking that might be why its wet
 

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