stevesxm

well... this seems simple and straight forward to me. get rid of all that junk and stuff you have there, put a correctly sized pump in the tank, run two 3/8 id hard lines back to the motor, put the regulator essentially where it is now or closer to the motor. then hard line from pump to short -6 to much better filter/separator than what you have there ( earls junk). from there short -6 to reg . from reg -6 to the motor. short -6 from reg return to hardline return to the tank. done. no problems again ever.

i would like to give you some sht and point out something that i often complain about here... i see all this zoomy braided line and fittings into fittings into fittings into adapters into more fittings... and at the end of it is some piece of old gas line with a couple 10 cent hose clamps on it..

if you are going to use aeroquip, don't do it because it looks neat. use it intellegently and learn to do it properly so that it actually does what it is meant to do. which is NOT just to look neat and impress your friends.

36Tango

Looks like this might be the hot setup, as it comes with everything I will add the return line back to the tank at the same time.
http://www.atlinc.com/2010_Race_Catalog/page18.html

Thanks for the education.

stevesxm

exactly what you need. i loved ATL stuff. you could call them on monday and talk to louis diamico , fax him a drawing and on thursday have what you needed. perfect every single time. great company.

36Tango

I will do so. It seems that if I need to take the time and have the expense, I just as well do it right.

When I took the pics of the current setup, the same thoughts went through my head about it being a bit cobbled. I am not a mechanic by trade and bought this boat last year with no engine, no drive, and it was red and white. It has been a helluva learning process. Forums like this, and people like you, have been alot of help.

Young Performance

Either a pump in the tank or one very close to the tank is the answer. As mentioned, efi pumps are terrible at pulling fuel. They are designed to push the fuel. You could probably just mount your existing pump near the tank and not have to purchase a new one, assuming it has a large enough capacity. You also need to be sure to mount it at least at or below the top of the tank.
The other common mistake is putting the regulator just after the pump. Put it after the fuel rail so that you are sending a full volume of fuel to the rail. Right now with the regulator before the rail, you are dimishing the amount of volume going to the rail. By plumbing it after the rail, it allows the rail to get an unimpeded and unaerated volume of fuel. The regulator will then return anything over the set pressure. This is the only way to plumb it IMO.
Also, as mentioned, you MUST return the fuel to the tank, especially if you get a larger pump. Since electric pumps are not rpm dependant like mechanical pumps, they pump the same amount of fuel at all times. At idle, you are returning 99% of the fuel that the pump is pumping. You will heat that fuel up really quickly. On the flip side, at higher rpms, you are not returning that much fuel.....certainly not enough to fill the return hose. So, you are introducing air into the fuel system. This air is going right into the suction side of the pump. This is why you are having problems with it losing it's prime at higher rpms.
Merc returns the fuel to the filter head in an effort to keep the engine self contained. It works (for the most part) on the smaller engines with smaller pumps. However, they still vapor lock from excessive heat buildup. They are also a ***** to prime when changing the filter since they don't pull much fuel because it is comstantly running in a loop.
Hope this helps. Give me a shout if I can help.
Eddie

36Tango

I attempted just to run a return all of the way to the tank, and it may have helped some, but niot entirely. I just ordered the ATL Black box, so that should cure all that ails me.

It makes perfect sense to have the regulator after the rails, but I do not see any taps that are after the injectors. Unless there is something that I am missing, I will just attempt to get the regulator as close as I can.

The fuel cell, as you can imagine, is in front of the first bulkhead and it is very, very tight. I will remove the front windshields to make it easier, BUT, I am still concerned about the fumes up there. Could I pump all of the gas out and then fill it with water? The foam inside the fuel cell needs to removed anyway to make room for the black box, so I will be able to dry it out when it is out of the tank. the fumes thing just kind of freaks me out a bit.

I do very much appreciate the insight that both of you have.

stevesxm

thats tough to say... first... are you sure the box will fix thru the access panel ? and second how big is this cell and can you just get it out completely to work on it... don't use any fans or anything to get rid of the fumes... i can't visualize it so its hard to advise...but don't blow yourself up...

GPM

Can you post pictures of the fuel rails ? the fuel return could be tapped into the fuel fill hose. Is there a check valve in your pick up ?

36Tango

It does appear that it will fit with no problem. After I completely drain it of fuel (using the fuel pump before I remove it), we will try to pull out the cell. It is pretty flexible, so I think that it will come out of the access hole. I hope that can happen, as it is a very confined space and the fumes do concern me alot. Even just a little static could be a very bad thing.

I'll take some pics and share as I tear into it. There is no doubt that this will cure my problem. Now my only challenege is to have it completed and any kinks worked out before the Lake of the Ozarks Shootout at the end of the month!

Thanks again

GPM

Good Luck !