2002 Outback LSV with TBI Indmar 5.7L fuel delivery problem / fuel pump pumping air o

[jnb0y]

Hi Moomba Forum, this morning I started up the boat on the trailer hooked to water to run for a few minutes while I got ready for an oil change. Engine stopped running after a few minutes. Immediately turned off the water and attempt to restart, runs for a few seconds. Repeat 3 more times then finally no more fire. Checked fuel level and gauge read nearly empty, oops. Maybe I ran it out of gas, it's sitting on uneven ground. Pulled it over to the gas station and filled it up and back home it still won't start. I've narrowed it down to fuel delivery problem. If I dribble some gas into the TB the engine starts for a second. When cranking it injectors aren't delivering gasoline. When cycling the key off-on the pump runs the requisite 2 seconds. I don't have a gauge for this so can't verify pressure, however I packed in some rags and pressed the Schrader valve on the pressure side going into the TB and when the key cycles it's pushing out air. I had a helper cycle the key 12 or so times with the pressure inspection valve depressed letting the air out hoping I'd clear the air out of the line but I haven't gotten fuel to come out yet.

Should I continue cycling until I get gas and never ever let it run empty again?

If I continue on this course of action will I damage the pump?

Am I way off the path?

If anyone has any thoughts I'd love to hear them.



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[Branden967]

I think your definitely on the right track with a fuel problem. I’d also go upstream a tad and pull the fuel filter. See if you can blow trough it, you may have clogged it when it ran out of gas. They when you cycle the key on let it sit for 15 seconds or so to build up a a tad more pressure before you fully crank it over. Hope that helps.

[jnb0y]

Thanks for your reply, I think the filter will be my next stop. I pulled the Schrader core out of the inspection port on the pressure side of fuel line and connected a clear hose and cranked the engine for 10-15 seconds and fuel finally emerged. I put it back together and was able to start the engine for 5 or 8 seconds and it stalled again. It's most definitely fuel starved and the filter seems like a sensible next thing to check before assuming the worst about the pump.

I'll post back on progress for the record, and hopefully a success story [emoji1696].

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[z28ke]

I recommend putting a fuel pressure gauge on it to help diagnose, but a new fuel filter is cheap and easy enough to try first. It’s pretty rare that a filter is so clogged it won’t flow enough fuel for the engine to idle and typically shows up under load at higher rpm first (but since it ran so low on fuel it could have picked up some trash).

[jnb0y]

Thanks for the recommendation. I just ordered a fuel pressure gauge, I'm long overdue on having one anyway. I also ordered a service manual for this engine for the same reason.

Anyone have a convenient way to run the fuel pump for more than 2 seconds without cranking the starter? I'm not above hot wiring but thought I'd see if anyone knows any easy ways to do this. I'd like to repeat last night's effort and run the pump for a little bit to see if its moving much volume or if a lot of air is stuck in the line.

[Tydogg]

Just did this as you commented on my thread . Pull the fuel line off the injector side of the pump , cycle and if fuel is come out then its on your injector side . If you pull the fuel line off and there is NO FUEL in the line you have pump problem, something in the line , or air in the line . If you ran it dry of fuel they can "vapor lock" . In which case you would need to remove the fuel line and cycle to remove the air until fuel reaches . Agree with getting a fuel pressure gauge and hooking it up . Should hold steady at 28-31 PSI with no bouncing or drop . If it slowly drops your obviously losing pressure , if its bouncing you have air in the line

[jnb0y]

The pressure gauge arrives today and I found the plug that goes to the pumps so I'll be able to jump them and run them for more than 2 seconds without cranking the engine. I'm hoping I just have air still in there or maybe junk in a screen. Everything was working great up until this. It's a little frustrating that this little headache may be a result of me forgetting to fill up my tank when I last put it away. Gotta work on my checklist discipline!

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[Tydogg]

When you hear the pump prime, do you hear a different sound than normal ? Try just turning the ignition on and off a couple times and listen to see if you hear , kinda like a bubbles higher pitch sound , may only last a second or two, maybe longer . If you hear a different sound ...its definitely air in the line

[jnb0y]

Hard to say. I've been around a lot of pumps and when I had nothing but air it definitely seemed like the pump was freewheeling. I've got my test procedure lined up, hoping I can make some time tonight to give it a go, but tonight I'm on Dad Duty so might have to wait til tomorrow. I'll definitely report back the outcome and steps I did.

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[jnb0y]

Update: I powered the pumps with jumpers and was mostly getting splashing up into my clear tube connected to the pressure port, not real flow like I hoped. So I ran one pump at a time and it seemed like the high volume pump was the one that was running but not pulling it's weight. I pulled it out and it spins but can't pump anything on the bench. And side note, there is gas in the motor housing sloshing around when I shake it. I don't think that's right. So I think the story will end up being that my primary pump went out due to seal failure. Possibly discovered because I maybe ran it out of gas? If that's so, I'm lucky it happened on the trailer and not in the middle of a lake hundreds of miles from my garage.

I'll order a new pump tonight. I'll update again once it's installed and I'm hopefully up and running [emoji1696][emoji1696]. Thinking I may as well replace the spin on fuel filter too since I haven't since I've had the boat.


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[Tydogg]

Good idea on the filter . I change mine every summer when getting the boat back out . Cheap solution that can protect and extend the life of parts

[jnb0y]

Hey, just a quick update that the boat is running again. I had a flurry of mishaps with some kitchen plumbing that pushed back my efforts on the boat but they're mostly behind me now and I got the new pump and filter installed. I'm happy to report the boat starts right up. I was a in a rush so didn't check the fuel pressure but will do that before buttoning everything back up just to make sure it's getting enough fuel to handle a load. So I'm calling it case-closed for now. Thanks for the input!