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Discussion Starter · #1 ·
I have a 91 Isuzu pickup with the 2.3 motor that I bought a couple of months ago and am now getting it on the road. I drove it about 30 miles yesterday and discovered a oil leak . To make a long story short ,the oil is coming from a hose that is about 6-8 inches long and the best that I can tell is connected to the fuel pump. The fuel pump is mounted directly under the intake manifold. The hose was stuck in a hole in the right hand motor mount and the oil was blowing back coating the under side of the truck. Now the question, I think that this hose is a return line for the oil that lubs the actuator system for the fuel pump as the pump is bolted to the head and the the pump is run off the camshaft .I cannot find any place on the side of the block or the oil pan for this hose to connect to so it would return the oil to the pan. The way that I see this the oil has to go back to the pan but I can't find any way to hook this hose up so it could do this. Has any one came across this hook up or have any ideas as to where it hooks up?
Any help would be greatly appreciated.
Thanks
Kenny
 

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I believe this is a fuel return line,not an oil line. The fact that it's leaking oil indicates a problem with the fuel pump diaphragm. I think this line should hook up to a rigid line mounted on the chassis that returns to the fuel pump.
Go to www.myisuzuparts.com and enter in your information. I'd then go to the illustration index and work your way through until you find your fuel pump. It will refer you to another illustration (I think 1-41) that you can go to and see the line. Hope this helps.
 

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shelby1 said:
I have a 91 Isuzu pickup with the 2.3 motor that I bought a couple of months ago and am now getting it on the road. I drove it about 30 miles yesterday and discovered a oil leak . To make a long story short ,the oil is coming from a hose that is about 6-8 inches long and the best that I can tell is connected to the fuel pump. The fuel pump is mounted directly under the intake manifold. The hose was stuck in a hole in the right hand motor mount and the oil was blowing back coating the under side of the truck. Now the question, I think that this hose is a return line for the oil that lubs the actuator system for the fuel pump as the pump is bolted to the head and the the pump is run off the camshaft .I cannot find any place on the side of the block or the oil pan for this hose to connect to so it would return the oil to the pan. The way that I see this the oil has to go back to the pan but I can't find any way to hook this hose up so it could do this. Has any one came across this hook up or have any ideas as to where it hooks up?
Any help would be greatly appreciated.
Thanks
Kenny
THAT IS A VENT LINE TO THE FUEL PUMP AND SHOULD BE LEFT OPEN, THE DIAPHRAM IN THE PUMP IS BAD , REPLACE THE FUEL PUMP, AND DO NOT PLUG THAT HOSE UP OR IT WILL FORCE THE OIL INTO THE FUEL PASSAGE AND THEN THE TRUCK STARTS SMOKING LIKE A FREIGHT TRAIN,, JERRY
 

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Discussion Starter · #4 ·
Many thanks for the quick replies....I do believe it is in fact a vent line for the pump.After airhead riders post I got to thinking I believe that what is leaking out of the line is oil and gas mixed because what I found under the truck was too thin to be just oil and coupled with the fact that the truck falls on it's face under hard acceleration which leads me to believe that the pump is bad (not supplying enough fuel ) and that the diaphragm is bad as Jerry said. This could be part of the reason this truck gets terrible gas mileage. I know that it needs a tune up and some other work. I have done a lot of work to it so far so I guess that it will need more before I can use it as a DD. I will not look forward to changing the fuel pump as it is directly under the intake manifold/carburetor and looks to be one that you need to bring a lunch with you.
Many Thanks for your help ,I''ll see what I can do to it this weekend if I don't have to help my son on one of his jobs.
As I said before many thanks for your help
Kenny
 

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shelby1 said:
Many thanks for the quick replies....I do believe it is in fact a vent line for the pump.After airhead riders post I got to thinking I believe that what is leaking out of the line is oil and gas mixed because what I found under the truck was too thin to be just oil and coupled with the fact that the truck falls on it's face under hard acceleration which leads me to believe that the pump is bad (not supplying enough fuel ) and that the diaphragm is bad as Jerry said. This could be part of the reason this truck gets terrible gas mileage. I know that it needs a tune up and some other work. I have done a lot of work to it so far so I guess that it will need more before I can use it as a DD. I will not look forward to changing the fuel pump as it is directly under the intake manifold/carburetor and looks to be one that you need to bring a lunch with you.
Many Thanks for your help ,I''ll see what I can do to it this weekend if I don't have to help my son on one of his jobs.
As I said before many thanks for your help
Kenny
KENNY , IT IF IS ALL READY MIXING OIL AND GAS, WATCH THE OIL IN THE PAN THAT IT ISNT ALL READY GETTING CONTAMINATED , IF TI IS DRAIN THE OIL AND USE SOME CEAP GRADE UN TILL THE PUMP IS REPLACED ,

CHANGING THE PUMP ISNT AS HARD A S IT LOOKS, REMOVE THE AIR CLEANER AND DISCONNECT THE LNE FROM THE THERMO HOUSING AND THEN RAISE THE FRT OF THE TRUCK AND REMOVE THE RT FRT TIRE AND LET THE BRAKE ASSY AND CONTROL ARM JUST HANG DOWN, BE SURE AND USE A JACK STAND UNDER THE FRT , REMOVE THE FUEL LINE DAMPNER , THEN REMOVE 2 NUTS HOLDING THE EGR ADAPTER PIPE TO THE BOTTOM OF THE MANIFOLD , OUSH IT DOWN JUST TO THE POINT IT IS ABOUT TO COME OFF THE STUDS , NOW TAKE A LONG EXT WITH A 12MM SWIVEL SOCKET AND REACH UP IN THERE AND REMOVE THE THE PUMP NUTS AND THE PUMP WILL COME RIGHT OUT , USE 1/4 DRIVE STUFF , 3/8 S MAY NOT FIT
 

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Discussion Starter · #6 ·
Wow ...Thanks Jerry I would never thought about going in tru the wheel well , I am a retired mechanic but I have been retired for over 20 years and I don't think about mechanic stuff as good as I once did.
As for the oil may being mixed ,I'm going to change it once I get everything fixed and it is not being driven .
I want to get this truck going and reliable as possible so it can be a DD ,we are on a fixed income and my full size Bronco is killing me on gas.I have some work that needs to be done on the Bronco but it will have to be out of service for me to do it ,so I need to have something to drive and the 91 is perfect.
Many thanks Jerry for the help,between you and the link Airhead posted I feel that I can get this truck going quicker than I first thought.
Thanks again
Kenny
 

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Discussion Starter · #7 ·
A new question on this pump, I ran into a old friend Saturday at the track and we got to talking and I found out his son has a truck identical to mine it had the same problem that mine has of oil leaking from the fuel pump vent tube ,he replaced the pump with a new one but it did not stop the oil from leaking from the vent completely ,greatly slowed it down but did not stop it.He pulled it back off cause he thought he messed the gaskets up or some thing a long those lines. He put it back on but it still not stop the leak. He finely gave up fixing it ,pulled the pump ,put a block off plate on and installed a electric fuel pump that was designed for carbed engines .
My question is ,has any one heard of this happening before ? I don't want to buy a pump (around 50 bucks) go to the trouble to install it and wind up pulling it and install a electric pump because it still leaks oil. This does not make sense to me unless there is something else with the pump that could be causing the leak.
Again thanks for the help.
Kenny
 

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shelby1 said:
A new question on this pump, I ran into a old friend Saturday at the track and we got to talking and I found out his son has a truck identical to mine it had the same problem that mine has of oil leaking from the fuel pump vent tube ,he replaced the pump with a new one but it did not stop the oil from leaking from the vent completely ,greatly slowed it down but did not stop it.He pulled it back off cause he thought he messed the gaskets up or some thing a long those lines. He put it back on but it still not stop the leak. He finely gave up fixing it ,pulled the pump ,put a block off plate on and installed a electric fuel pump that was designed for carbed engines .
My question is ,has any one heard of this happening before ? I don't want to buy a pump (around 50 bucks) go to the trouble to install it and wind up pulling it and install a electric pump because it still leaks oil. This does not make sense to me unless there is something else with the pump that could be causing the leak.
Again thanks for the help.
Kenny
IF HE USED AN AUTOPARTS STORE PUMP , HE JUST GOT A BAD PUMP. NOT UN COMMON, AT ALL, HOW LONG HAS THE FACTORY PUMP BEEN ON THERE COMPARED TO THE PARTS STORE PUMP,
 

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Discussion Starter · #9 ·
Jerry the oil leak continued after installation of the new pump just at a reduced rate,it did not stop it completely . He pulled it back off (if fact several times ) and could never stop the oil leak. He finally gave up and put a block off plate in place of the pump and installed a electric fuel pump.
As far as parts store pumps I have always had good luck with them (for domestic cars ) so I have been thinking this over and I believe I'll go ahead and buy a parts store pump as there are no original parts ( new car dealers ) available in this or the surrounding area and see what happens.Will just have to wait till funds become available.
Many thanks for the help
Kenny
 

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Discussion Starter · #10 ·
Update: I changed the fuel pump this weekend, and it went much like Jerry said.....just more complicated.
As Jerry said you go in tru the right front wheel well,pull the rubber splash shield off the plastic clips that holds it on and you have access to the motor.... but there are a few more things that you might as well go ahead and do because you will have to do it later.Loosen the EGR feed pipe that is connected to the exhaust manifold on the driver side of the engine, a small pipe wrench will do if you don't have metric wrenches that big ( I don't) now when you loosen the flange under the bottom of the carb you can drop it down away from the manifold,and while you are there remove the heat shield that is between it and the fuel pump,after pulling the fuel lines you can now remove the fuel pump. Now you will discover that there is not enough room to scrape the gaskets off of the head if you have a AC compressor bolted to the block. Back off of the belt tension with the adjuster so the belt will come off and remove the four bolts holding the compressor to the block and from the front of the truck wiggle/pull the compressor up and out of your way and tie/prop it there.You will have the room to scrape the gaskets from the head.This was a OEM pump and the gaskets were bonded to the metal good ,I had to make a small scraper (cut down a old screw driver) to scrape all of the gaskets off.
This was a very poor design to put this pump where they did ....I believe my 9 year old granddaughter could have figured out a better place to put it :wink: ....I am glad that I no longer mechanic for a living.
Kenny
 
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