Engine stalls while it idles after fuel filter change. Runs great while in gear.

[Gfmclachlan]

I've read a lot of threads about engines stalling at idle, but not too many responses with final outcome. 87 johnson 60 hp. Inboard fuel tank.Opened her up for the season, started great, ran her twice(and idled) and worked wonderfully. But then i changed the fuel filter and the problem began. I read suggestions to add fuel and top off the filter when replacing it(not the small filter in the engine) but I was unable to and self primed with primer ball and then started her up and let fuel pump do the rest. Now I'm not sure if it didn't fill all the way and air is in there. Also, I did open the small filter in the engine and cleaned the screen although it was basically clean, and you can't screw that up, so I doubt that can be an issue.
-if i catch it in time and prime with the ball the engine keeps working.
-i changed the fuel filter again(same procedure), problem continues.
-i changed the fuel lines from and including fuel filter to engine.primer ball in right direction.
-there is are no fuel leaks.
- the vent for tank seems ok.
How tight does that fuel filter have to be on housing? I tightened it pretty good, but not sure if air is getting in there. But maybe its just a coincidence and has nothing to do with changing the filter? But that is when the problem started.
Thanks.

 

[emdsapmgr]

Re: Engine stalls while it idles after fuel filter change. Runs great while in gear.

You talk about the filters like you have two of them on the engine. The stock one is the whitish one just ahead of the VRO pump. I believe you refer to it as "the small filter" on the engine. Do you have another? (a large one?) Perhaps a fuel water separator filter?
That engine was never sold with a fuel water separator from the factory. While I'm a fan of the fuel water separators in general, it's possible it is actually restricing fuel flow, esp at low (idle) pumping. You could even try bypassing it as a test.

 

[Gfmclachlan]

Re: Engine stalls while it idles after fuel filter change. Runs great while in gear.

Right, a fuel water separator(obvious now that you say it), my bad. I bought it set up with one, and it worked great. Even after i replaced it twice and the housing and all the lines it still is a problem. I guess i can try that as a test. I read in one thread someone "burped" the fuel lines....meaning they removed the fuel water separator and pumped the primer ball ...to get air out? I dont know, the thread wasnt very explicit.

 

[emdsapmgr]

Re: Engine stalls while it idles after fuel filter change. Runs great while in gear.

When you pump the fuel hose bulb each am when you start the engine for the first time, that should force fuel all the way to the carb bowls for the first start of the day. That should be enough to get you going all day. You should not need to re-prime the fuel hose till the next day. Some things to check: Problems could be: an air/fuel leak somewhere in the fuel hose routing. Bad ball valves in the fuel hose bulb. Restriction in the built-in fuel tank anti-siphon valve. restrictive fuel/water separator filter. weak fuel pump.

 

[Gfmclachlan]

Re: Engine stalls while it idles after fuel filter change. Runs great while in gear.

Is it safe to bypass the fuel/water separator even if only for ten minutes? If so, it may be a good place to start. Maybe I should try an more expensive F/W separator? I've been using a $12 sierra. How do I begin to find an air leak? Is there a way to purge any air in the lines? Lastly, maybe the fuel pump was worn out some when it needed to work overtime to fill the fuel water separator with fuel? How can i test that? Thanks.

 

[Gfmclachlan]

I readjusted the inline fuel filter and The problem seems to be solved. It was leaning more horizontally but when i adjusted it more vertically it seemed to work so far. Also tightened it more maybe small air leaks was finding its way in.