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Vapor pump/vapor seperator diagnosis?

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Georgiaboy67

Advanced Contributor
I have a 97 evinrude 115 E115eleua. Does anyone know of a way to diagnose whether I have a bad vapor pump? I have a fuel issue and don't have vacuum gauge or pressure tester that I own to see if I have a bad fuel pump or not. I replaced it last year, and up until the end of march the fuel system has been good. At work we were able to determine that the fuel pump is pulling adequate amount of fuel from the tank, but then we hooked up a gauge to the starboard fuel manifold, and the motor was not getting enough fuel. So I've rebuilt some of the fuel bracket components.Put new fuel bracket on, new vst cover, new o ring on vapor pump, new o rings for both hoses that lead to either fuel manifolds, new o ring on this 90 degree nipple on the back of the fuel bracket. Does anyone know how to test to see if I have a bad vapor pump? The fuel pump was replaced last year, the vapor pump is the original 97 model vapor pump that the motor has always had.. so I'm guessing this might be the culprit? I read somewhere that you could possibly pull the vent line on it and see if you can run it long enough before it starts dumping raw fuel. The post stated if it doesn't act up then you the vapor pump is bad.
 
We only have two techs at work.... and only one came up with a safe way to test to see if the vapor pump is bad. But I really need the boat by this Saturday for a lake trip to guntersville. And he now has a funeral to attend to tomorrow.. not sure when he'll be back. That's why I'm asking here
 
It's still doing it.. this most recent trip it ran a minute longer,(literally) last trip it quit running within like 10-15 seconds of being on minimal plane speed. Evinrude shows a fuel pump rebuild kit for mine, I think I'm gonna do the fuel pump rebuild and replace the vapor pump and cross my fingers that it fixes it. The motor is still being starved for fuel, even though the fuel pump is pulling enough fuel from the tank, it's just not giving it to the motor. Which shows air leak or bad pump. and I'm scared to run it much more because if I haven't already this issue can cause catastrophic damage to my powerhead with continuous running like it is.
 
Fix the VRO or the air leak in fuel system. Test the VRO with vacuum/pressure testers.
 

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What's the intermediate housing? Is that the bracket and such? Or is that in the vro? Is it still a possibility that the original vapor pump could be failing? If the check valve is bad? I know vapor pumps can't be rebuilt?
 
The vro holds pressure when it's pulling fuel. When he hooked up the gauge to the fuel manifold the pressure was not steady, it was at 0. We had to prime the bulb just to get it to 5. He said it should
be between 5 and 7, and that it should fluctuate a bit, but not at the rate it was. Pressure slowly decreased to about 2. And he said I had an air leak somewhere.
 
Never mind I found what the housing was. Just opened the manual. I'm looking for a rebuild kit on my fuel pump, what all would come with it? In the rebuild kit? Would the housing and such one with it?
 
Hey faztbullet you've read some stuff on those bovine scats that did the powerhead work. So I'm looking at the paperwork and not only do the part numbers not match up for my motor but neither does the price. They showed a vro pump for only 325.99... even on sale on this site fuel pump has never been that cheap. Lowest I've seen it is 423.99. And right now it's $583
 
What would be a possible reasoning why a fuel pump would be almost half price of original? I think they threw a used pump on there. I matched the numbers to one of the older part numbers on this site. So it is the right pump. But now the question hinders why would you give a first time customer half off of a fuel pump? After charging full price on water pump replacement, new powerhead, etc?
 
Take it off and test it as if check valve in main body is bad or air motor housing is crack you don't have a rebuild kit with no use.
 
The check valve is in the body of VRO and is not replaceable...follow the VRO testing chart as using pressure/vacuum testers test the check valve.
 
Alright I'll see what I can accomplish today. I gotta do everything possible before the weekend. Work said it is probably the vro since when the motor acts up I have someone squeeze the primer bulb and the motor picks up and runs fine for a minute
 
We pulled the vro off today and did the test that's in the manual that has the chart like you showed fazt... pump is good.they gave me the bigger o ring on the nipplenon the back of the fuel bracket since that nipple moves a lot!
 
Got the new o ring on. Honestly not really confident it'll fix my issue. Only other thing left is the vapor pump. Everything else on that bracket besides the primer and vapor pump would be replaced. And the float inside the vapor seperator which was parallel to the cover
 
Hey fazt I noticed the hose that goes from the bottom of the vro to the pulse limiter fitting on the crankcase spins real easy even with a clamp on it. Is it supposed to be like that or could that be my air leak? I've done most of everything else to find it
 
We followed the fuel pump test chart in the manual exactly and the pump is good. I was glad that I finding have to buy a $600 fuel pump but I was mad that I still don't have the answer as to where the hell this air leak is
 
**update** I plan on running the boat tomorrow. I replaced a couple wire clamps on the motor that weren't even holding the fuel hoses in place. You can slide the clamp whichever way even with it "tightened" so I tossed them and put new clamps on the hoses. I hooked up a clear vinyl hose that I bought to the fuel manifold where we had seen a lot of big air bubbles previously. I ran the Motor on the hoses for almost 10 minutes. Revving it and everything. I didn't hear any fuel pump ticking, and there were 0 air bubbles going the manifold this time. Maybe I have finally gotten this fixed after all this frustration and effort
 
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