Electric fuel pump info in merc manual

[telstar1]

Where does one find fuel pump info in a Merc manual? I have a 2001 5.0 carbed,recently aquired Merc manual(s) #31 for this unit. Am troubleshooting a fuel issue and would like to see what they say abt the elec fuel pump. Havent found a thing. Where do I look?
Thx
T1

 

[alldodge]

Re: Electric fuel pump info in merc manual

If your looking for the electrical side try this
http://www.boatfix.com/merc/Servmanl/16/16F4R2.PDF

 

[Don S]

Re: Electric fuel pump info in merc manual

If your looking for the electrical side try this
http://www.boatfix.com/merc/Servmanl/16/16F4R2.PDF

Wrong manual, that is for a big block 93-97. He has the right manual (31), just can't find what he's looking for in it.

Am troubleshooting a fuel issue and would like to see what they say abt the elec fuel pump. Havent found a thing. Where do I look?

What sort of problem are you trying to troubleshoot? Section 1C covers the troubleshooting.

 

[telstar1]

Re: Electric fuel pump info in merc manual

Wrong manual, that is for a big block 93-97. He has the right manual (31), just can't find what he's looking for in it.





What sort of problem are you trying to troubleshoot? Section 1C covers the troubleshooting.

I have a vapor lock issue,thought Id check pump pressure to spec but no info whatsoever found so far in the manual which is disappointing.Went for yrears using the much pilloried Clymer manuals and finally sprung for the merc, first time out of box no info(Clymer at least mention the pump)Hopefully someone can tell me where info is hiding. Meanwhile I googled up a rather good Merc bulletin on vapor locks that I think will get me solved.: Vapor lock or what?

 

[Don S]

Re: Electric fuel pump info in merc manual

What makes you think it's vapor lock? Here is the service bulletin, have you done any of the testing in it?

View attachment SB 99-7.pdf

I think one problem people have with the OEM manuals are that they are designed for Merc techs that have gone through training, not the average DIYer. So there isn't a lot of hand holding.
If specific problems crops up that isn't covered in a manual, they usually come out with a bulletin or even manual supplements.

 

[telstar1]

Re: Electric fuel pump info in merc manual

Thanks for the link. Between orig. posting and now Id googled and found that bulletin too. It seems like it will help immensely.My issue could be best described as "(sometimes) engine starvation on holeshot while warm,particularly prevelant while others are watching".Very annoying. Anyhow Im going to go from one Racor and a Merc spin on to one Racor,and eliminate about 4 90 degree elbows. Im pretty hopeful this will cure problem. I had not considered the 90 degree elbows to be an issue, the bulletin says they can be.Ill report back. Thanks again.Re the manual I wonder if theres a site listing the supplements and bulletins?One would think a manual would come updated to most recent info but I suppose not.

 

[Don S]

Re: Electric fuel pump info in merc manual

My issue could be best described as "(sometimes) engine starvation on holeshot while warm,particularly prevelant while others are watching".Very annoying.

That doesn't sound like a vapor lock to me, more like a hesitation. If it was actually a vapor lock, it wouldn't run at all, and it sounds like you can start it up if it dies, and then go.
I would think carb mixture adjusment or an accelerator pump problem, maybe timing. But not vapor lock.

 

[telstar1]

Re: Electric fuel pump info in merc manual

Hmm . It runs perfectly at all other times,and I can overcome the fuel starvation or vapor lock or whatever it is by remembering to hold the momentary switch for the walbro 5 psi (priming) pump that I have plumbed in between tank and filter. In fact if I catch it soon enough I dont even go back down completely into the hole.In other words if I provide some extra fuel pressure it doesnt do its thing. Maybe it isnt vapor lock I dont know thats why I was trying to find some specs on pump,then see how they compare to actual(which I havent got a gauge hooked up for yet either) Anyhow Im going to try the fuel line uncluttering thing and see what that brings. Annoying thing is I can go weeks or months without this happening,not sure if I can simulate the exact conditions necessary for a stall so I can actually determine for sure that i have cured the issue.

 

[achris]

Re: Electric fuel pump info in merc manual

The only specification on the pump is the pressure, 3-7psi. Measure your pump pressure. If it's in that range, then it's working properly... What you may have is an air leak between the tank and the pump... Try with a remote (outboard style) tank and a different fuel line.

Chris.....

 

[Don S]

Re: Electric fuel pump info in merc manual

Hmm . It runs perfectly at all other times,and I can overcome the fuel starvation or vapor lock or whatever it is by remembering to hold the momentary switch for the walbro 5 psi (priming) pump that I have plumbed in between tank and filter. In fact if I catch it soon enough I dont even go back down completely into the hole.In other words if I provide some extra fuel pressure it doesnt do its thing. Maybe it isnt vapor lock I dont know thats why I was trying to find some specs on pump,then see how they compare to actual(which I havent got a gauge hooked up for yet either) Anyhow Im going to try the fuel line uncluttering thing and see what that brings. Annoying thing is I can go weeks or months without this happening,not sure if I can simulate the exact conditions necessary for a stall so I can actually determine for sure that i have cured the issue.

Do you have the purple/yellow wire going from the starter solenoid to the oil pressure switch attached? That would run fuel pump during cranking of the engine. Otherwise, your pump will not run until you have oil pressure.

A warm engine should start up with the fuel in the carb, even if it was vapor locked. So why isn't there any fuel in the carb?

You have some fuel delivery issues, and it's not vapor lock.

Along with the pressure check on the fuel pump, and checking your carb for a leak after shutdown, and seeing if the fuel pump wiring is correct here is some more information.

HOW TO: Testing your boats fuel system.*/ 283269

One other note, those fuel filters are not designed to be on the pressure side of the pump, only the suction side.