Fuel leak / starting issue

joshua bebbino · Dec 13, 2016

Hello all!

So my problem is this, let me start by saying I read tons and tons of posts about this issue all through the internet, and I haven't come up with a set way to determine my problem.
So what I'm asking for is how you guys would go about determining the problem, as in what to check first then move to that, any help would be greatly appreciated!

So my 86 m1008 was having a hard time starting the typical start stall stuff everyone posts. I recently switched to the spin on fuel filter base and filter and was pretty confident this was gonna solve the problem. I did this about a week ago, up to that point my only problem was the hard starting and a cracked power steering bracket. I addressed the fuel filter problem and have been gradually attempting to remove the god dam pulley, but now I have noticed a fuel leak about two inches in front of the bellhop sing. The leak is about a 12x12 inch circle in the ground, the hard starting hasn't gone away even with the fuel filter change, the truck has been started but I haven't been driving it for about a month. I never had a problem with leaking fuel untill after I changed the fuel filter base.

The filter base is dry and the lines attached are dry no leaks. I've read some posts about fuel draining back which could be an issue as the truck sits in my apartment complex it is on a gentle slope so the front end is higher.

Why question is what's my next step in solving this leak, I was thinking that since I haven't had the leak before maybe while changing the fuel filter I pulled on a fuel line alittle and did something? I don't know if it's what I changed but like I said It only started showing a leak on the ground after my switch of the filter base. It has been cold here in nc about low 30s so maybe from sitting a seal hardeNed up?

Any help would be great thanks all!

jbayer · Dec 13, 2016

You could start by not using the lord's name in vain.

joshua bebbino · Dec 13, 2016

Me and the Lord talked and after seeing what I'm going through he was okay with it! But good looking out

Skinny · Dec 13, 2016

He used the word "god" and not "God" so technically he was not specifically referencing any particular or formal invisible entity so probably arbitrary at this point...

Any fuel leak will give you starting issues, think of your fuel system like a hydraulic system. If it leaks, you possibly are bleeding down and introducing air into the circuit. If this was my truck and you have not already done it, I would start back at my fuel tank and work my way all the way up to the injection pump. Replace all of the lines and clamps without question. I would also put a new AC Delco lift pump in as well. It's the only way to ensure you have a trouble free fuel system.

Barrman · Dec 13, 2016

Did you put on new fuel lines when you did the filter swap or just re use the 30 year old ones? You seem to be getting fuel to your filter ok. The 1/4" line from the filter to the IP could have cracks in it that you made bigger moving it around during the filter swap. That would also cause the fuel to leak into the engine valley which drains down the back of the engine.

Look in your engine valley under the intake with a flash light. Figure out if the leak is coming from the IP inlet hose or just as possible. From the IP throttle shaft seals. If the valley is wet from almost at the water pump end all the way back, it is most likely the shaft seals. They can be changed out in the truck. However, if they are leaking what about the other wear parts inside the IP? Replacement or rebuild of the IP is in my opinion the best fix. Put a new 1/4" line from the filter to the IP at that point too.

Drock · Dec 13, 2016

Replace ALL rubber fuel lines, and recheck your filter fittings. Did you use thread sealer on the fittings? Also a neat little trick is to temporarily replace the return fuel line with a clear hose to show if any air is entering the system. The (return line) is the short hose coming out of the top of the injection pump that goes down the front of the motor.

joshua bebbino · Dec 13, 2016

Thanks so much for your prompt responses guys! So, I did put new lines in when I changed the filter base and filter. However, I have not gone through the lines running from the tank all the way up. As you gentlemen have stated I do believe air is getting in somewhere, but I was baffled by the leak, like I mentioned i never have seen a fuel leak on the truck but that doesn't mean I never had one, it could of been masked by minor oil leaks and such, I also do believe the leak is coming down the valley bc it seem to be dropping between the bellhousing and oil pan, in that area, I'm kinda hoping it isn't the ip but now believe that my hard starts might not have been from a bad filter base as I had thought.

So, from the info you guys have genourously provided me, my plan of action should be, check my news lines I put in to the filter base, check filter base, check and replace lines from the tank on, replace lift pump, and check the ip and see if the throttle seals are leaking, anything else? Once again gentlemen I appreciate the help.

joshua bebbino · Dec 13, 2016

Thank you gentlemen for the prompt responses! So, I did replace the fuel lines when I changed the filter base, and from everyone's responses, I do believe I have an air leak, Ijust thought it had to be the filter base bc I never really had a hard time starting untill early summer, when I would have trouble starting in the morning, typical start and stall then wait 10 min and start again, once it was started I would be good for the rest of the day no matter how long it sat while I was at work, untill early fall when the Temps dropped alittle it would give me more trouble on the second start.

As for the fuel leak I have never seen one bf on the truck untill I recently changed the base and lines, I know that doesn't mean I never had one it could have been masked by minor oil leaks or was a bad leak.

So my plan of action based on everyone's responses should be, check the new lines, check the new base and fittings, check and replace lines from the tank all the way forward, get a new lift pump, check the valley and see where fuel is leaking from, check the ip, anything else? I appreciate the responses and time it takes to repley gentlemen!

joshua bebbino · Dec 13, 2016

I will also do the clear hose trick to test that as well!

Skinny · Dec 13, 2016

I wouldn't check, I would personally just replace them so every flex line is of the same age. It only takes one to cause a problem. Another good thing to do is drop the tank and replace the sending unit sock. They can plug up as well. This is also an opportune time to change those lines as well. It is suck work but once you put your time in you know what you have. Good for another 30 years!

joshua bebbino · Dec 13, 2016

10-4 , I will replace all lines at least I know then , that half of the truck is taken care of, I would just need to address the leaking problem or maybe that might solve it

honda · Dec 13, 2016

I was stuck with foamy fuel and decided to replace all the rubber from sending tank to IP which meant dropping the tank. As long as the tank was getting dropped it was time to install a maintenance port along with a new 31 gallon tank and sending unit. Clearances for the new tank were tight, ( especially up top) but it worked.

Cut out a portion of the bed, welded in steel 1/8 x 2 inch soft steel frame, tapped holes, body caulk inside corrugated openings and re-install cutout panel ( which was reduced in size by about 1/32 inch to allow for easy snag-free installation and removal of the inspection/service access plate. Steel stock is topped with foam insulation for complete seal. This bed has 4 layers of lizard skin topped with Line-x, so metal fatigue is not a factor.

Glad I did it, however the real leak was discovered where the fuel delivery rubber line entered the fuel pump. Seems when the motor mounts broke and the engine dropped, the rubber hose feeding the fuel pump got pinched. SOS for a lot of you guys. But hey, I got a new fuel delivery system out of it with an inspection port to boot. I stock a spare filter base, filter and pump, just in case or should I say, when the time comes.

Barney Fife · Dec 13, 2016

I've got an '85 M1009. Does the length of time the wait light stays on have anything to do with the IP or line pressure?

Hasdrubal · Dec 13, 2016

Barney Fife said:
I've got an '85 M1009. Does the length of time the wait light stays on have anything to do with the IP or line pressure?

Nothing whatsoever, its dictated by a temperature sensor.

Drock · Dec 13, 2016

Incase you didn't know there's also rubber fuel lines that run under the intake.

richingalveston · Dec 13, 2016

Honda. can you give us info on that tank.
Also, can it be done without cutting bed? Looks like that was not completely necessary and I would like the larger tank but no hole in bed.

does the factory tank guard/shield work with your new tank or was it deleted.

Thanks
Rich

cucvrus · Dec 13, 2016

honda said:
I was stuck with foamy fuel and decided to replace all the rubber from sending tank to IP which meant dropping the tank. As long as the tank was getting dropped it was time to install a maintenance port along with a new 31 gallon tank and sending unit. Clearances for the new tank were tight, ( especially up top) but it worked.

Cut out a portion of the bed, welded in steel 1/8 x 2 inch soft steel frame, tapped holes, body caulk inside corrugated openings and re-install cutout panel ( which was reduced in size by about 1/32 inch to allow for easy snag-free installation and removal of the inspection/service access plate. Steel stock is topped with foam insulation for complete seal. This bed has 4 layers of lizard skin topped with Line-x, so metal fatigue is not a factor.

Glad I did it, however the real leak was discovered where the fuel delivery rubber line entered the fuel pump. Seems when the motor mounts broke and the engine dropped, the rubber hose feeding the fuel pump got pinched. SOS for a lot of you guys. But hey, I got a new fuel delivery system out of it with an inspection port to boot. I stock a spare filter base, filter and pump, just in case or should I say, when the time comes.

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https://youtu.be/VKcAYMb5uk4

joshua bebbino · Dec 13, 2016

Is installing an eletrical fuel pump as easy as , just finding the section of rubber hose on the passenger side frame , installing a pre filter , then installing eletric pump and then just running that hose to the fuel filter? AND of course hooking up the switch to the ignition.

goldneagle · Dec 13, 2016

joshua bebbino said:
Is installing an eletrical fuel pump as easy as , just finding the section of rubber hose on the passenger side frame , installing a pre filter , then installing eletric pump and then just running that hose to the fuel filter? AND of course hooking up the switch to the ignition.

My mechanic and I found a junction point under the truck that has a metal cover over it. We installed an electric fuel pump in-line under that cover. Now when I am waiting for the wait light to go out the electric fuel pump is priming the system. Makes for easy startup.

snowtrac nome · Dec 13, 2016

there is a t block behind the passenger side inner fender well I have found steel lines come loose there before causing air leaks.

Fuel leak / starting issue

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