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Fuel leak under intake manifold

motorboat4

motorboat4

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I have a fuel leak coming out from under the rear of the intake manifold. The garage I went to replaced the fuel manager housing thinkin it was that. But it is still leaking. A large amount of fuel runs out during starting, and it continues to drip slowly while running. Anyone have an experience with this? Could it be a loose injection line or is there some seal or something on the injection pump that breaks. I asked the shop if they had a scope that they could use to look under the manifold but they don't. Its a 95 GMC Suburban 6.5 with 165,000 miles. Would appreciate any input. Thanks.
 
Yes, Ive damaged the fuel line from the fuel manager to the drain and I've damaged the fuel line to the IP. you might have to pull the intake manifold to get at everything. I've went ahead and replaced all my fuel lines because they all had age cracks and were a bit brittle
 
Thanks Drado, I'm not capable of any major engine repairs, will have to let the shop do the work. The last thing I did to it was when I replaced the Lift pump under the drivers side. Incidentally I did encounter a problem at the time. I replaced the LP because the old one was leaking from its casing. After I installed the replacement, the idle was just a little slow. I replaced it again but it remains slower than before. Its been that way ever since.
 
I'd find a better shop. any shop worth a darn would have replaced those lines under the intake while they were in there and also diagnosed it better. lines can be replaced without removing the intake.
 
IP might be leaking from weep hole.
and yeah how could the shop let it go still leaking or atleast tell you where its leaking from!
You can see alot with an inspection mirror and good flash light.
 
When would the weep hole leak and why? Would something be worn or dried out? Sounds like that would require a pump replacement. I dread that. Its been good for about 75,000 miles. and 10 years. Put about 5,000 miles a year the last 5 years since I retired.
 
It isn't that hard to replace the lines. 15mm deep socket to free the FFM from the intake manifold. That will give you enough wiggle room to see which lines are the culprit: Input to the FFM from the tank, Output to the IP, output to the water drain or "T" Valve, or, return line to the fuel tank. You may need to remove the upper intake to get at the FFM to IP inlet hose though. The other hose to look at is the IP return line at the front of the pump. Short, 2", formed into an open "U" and connects the IP to the metal return line.

Sorry that these are the only photos I have of the lines.
FFM Fuel Lines OPS.jpg

IP Return Line.jpg

Regardless, screwdriver to get the band clamps off or small 1/4" drive socket. Use the old lines with a hose barb to pull the new lines under the lower intake.

Lines to and from the fuel tank are the ones running down the back of the motor at the fire wall. You have to practically be "contortionist capable" to reach them for replacement but you can at least get it narrowed down if you choose to still have the work done by someone else.

Where are you located anyway?
 
motorboat4 said:
When would the weep hole leak and why? Would something be worn or dried out? Sounds like that would require a pump replacement. I dread that. Its been good for about 75,000 miles. and 10 years. Put about 5,000 miles a year the last 5 years since I retired.
Click to expand...

Bad seal.
If it is the weep hole you'll be looking at an R&R.
 
Let's check the hoses under the intake first before trying to mess with the IP.

You can replace those hoses and raise the FFM so you don't have to feed it under the intake anymore.
The benefit is the ability to see leak.

There are also 2 o-rings that is prone to leaking on the FFM, when you change this, you may want to change those also.

There is one picture in my garage that shows the raised FFM

You can use M10-1.5 threaded rod, cut to around 9 inches long.
Use a few nuts to hold it and use the current wire harness plate to reduce vibration.

Now, if it is still leaking under the intake, then it may be the IP weep hole.
 
Make sure you use fuel line rated for bio-diesel

There is a thread here that says how much of each size line you need. It is something like 4' of 1/4" 2' of 3/8" and 2' of 5/16"

I had it in an email but since yahoo changed I'm missing a lot of the emails I had info stored in.
 
Make sure you use fuel line rated for bio-diesel

There is a thread here that says how much of each size line you need. It is something like 4' of 1/4" 2' of 3/8" and 2' of 5/16

The stores around here aren;t much for keeping the bio rated hose in stock. But all the local truck stops and implement dealers have it

I had it in an email but since yahoo changed I'm missing a lot of the emails I had info stored in.
 
It's on the bottom of the FFM. could be it needs new orings Leroy has them. Also check where the wires come out can leak there as well, will need a new heater if it is leaking there
 
The shop should repair that free of charge, the heater is a part of the fuel manager that they replaced.
 
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