(UPDATE) Elec. Fuel Pump hanging on a rope

I have a 1990 233 XL Regal Ambassador, with a 5.7 Mercruiser. The engine has been replaced some time ago. I recently purchased this boat and was in the process of solving a problem. While skimming through this site and reading other post, it dawned on me that the next time I was in the engine compartment, that the fuel pump (looks like a fuel filter w/ two wires coming out of it) was attached to the carb by a high presure threaded end hose, the other of the pump had a regular car rubber fuel line with hose clamps attached it and to the gas tank.

Due to the fuel combustion sensitivity, I've seen on this post more secure fuel lines with a water seperater. I did fine a water seperater that must of been taken off of the old motor. The new motor does not have the opening for a mech pump. To make matters worse, the fuel pump was strung up in the air so that it wouldn't vibrate against the stringer. One of the wires to the pump has a 10 amp fuse and is attached to (S) side of the starter solenoid.

I've read something like it had to be on the (R) terminal of the solenoid and something to do with an oil sending unit.

Please tell me the correct way to make this work.
Thanks.

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

Can someone tell me the right way this is installed.

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

You mentioned that the engine has been replaced. It would be a good idea to find the serial# of the engine and post them. Then someone might be able to help.

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

The S terminal has 12v when the key is in the start position only. The R terminal has 12v when the key is in the run position. The power to the pump should go through the oil pressure switch basicly.

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

So what are you telling me? Is it on the right terminal (S). Also, shouldn't the fuel pump be mounted on something not suspened in the air and held by a rope. I suspect there was a conversion from mech to elec. Can you tell me how the elec fuel pumps are set up, aren't they supose to have a water seperator.

My fuel pump is shinny bronze with 2 wires coming out of it (Is it marine use) , one going to the starter, the other I don't know. It's the size of a regular car fuel filter. I've seen on the web elec. fuel filters looking more like skinny cylinders.

Presently, the fuel line comes out of the tank attached with a hose clamp, then connected to a automotive fuel fliter, the line is connected with a hose clamp to the bottom of the fuel pump, the top of the pump has a screwed in fuel pressure line connected to the carb.

Any thoughts on the correct way to set up an elec. fuel pump

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

In regards to the serial number, it is as follows:

10243880, 95-2000 Vortec, Gen I, roller cam one piece.

I got that info from Rapido Marine, I don't what it all means.

Does anyone?????

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

Forget serial numbers. The engine has no cast opening for a mech pump, so Merc moved to electric pumps. That was about 1993, some blocks were earlier, some later.

A bracket was bolted in place of the old mech pump and the electric pump is placed in the bracket with a couple of rubber grommets (vibration reduction)...

Like this......



Wiring....

The power for the pump is supplied from the key, through the oil pressure switch. There is a bypass from the starter motor solenoid directly to the pump from the 'S' terminal. This allows the pump to run while the engine is being cranked, before oil pressure is up....

The oil pressure switch is there so that if the engine stalls the pump stops, so remove the risk of flooding the engine (and bilge) with fuel.

Also the fuel line from the pump to the carb should be steel... NOT rubber.

Chris..........

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

Chris,
Thanks for the diagram, that's great!
Where can I fine this bracket,
Is there a certain shape fuel pump to use,
What gph should I have (5.7 Merc 700 Holley)

There is a metal neck coming out of the gas tank connected to a rubber fuel line with a hose clamp. How would I do a metal line. I'm hoping who ever did this that they didn't cut the end of the tube from the tank. If they did how would I convert to metal. Also, do I need a water seperator (fresh water use).

The day before I ran it on muffs, went to the lake the next day NO Gas, it did start briefly w/ starter fluid. Yes, I have 1/4 tank of fresh gas. The pump felt warm and it did not make noise as it done previously when the key was turned on. Does this mean my pump is shot or something else????

PLEASE ADVISE!

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

OK... Re-read you OP, you have a high pressure steel braided hose from the pump to the carb, yes? You need the hose from the tank to the engine to be rubber (vibrations).

As for not pumping fuel... Get an outboard fuel tank and run the hose from that to the pump.... If you get fuel, you have a problem in the main fuel tank...

Brackets.... Go to a site like THIS. You need parts #1, #3, #7, #17.... And any others you want...

Chris.........

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

I really appreciate your help, Thank You!

I can understand why they hooked it up the way they did. Wow! those prices are HIGH.

I guess I have to use the fuel pump in the diagram and that would be the correct GPH?

So that I understand, your saying the rubber fuel line coming out of the tank is OK.

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

DO NOT pull your start bypass wire from the S terminal.
if the other side is wired correctly it can lead to a starter not disengaging when the key is on.
use the R terminal to the pump red,use the purple ign wire to the pressure switch 1 terminal and another purple or red to the red on the pump(+)
the S terminal has 12V applied to it to energize the solinoid, when the solinoid contats close the R terminal is contacted by the disc and supplys 12V out ONLY while the solinoid is engaged.

so if its wired to the S terminal and you crank a bit,build up some oil pressure,typically 3-5 PSI, then the engine starts you are now back feeding the S terminal with the IGN switch terminal not the S terminal on the IGN switch and the starter remains engaged.

seen it more than once and it can look nasty.
R terminals original purpose was to supply full 12V to the ign coil,when old points were used, to inure strong spark at cranking speeds.
now with modern ign systems some use it to power up the fuel pump while cranking.

check with the fuel pump manufacturer for fuse size.

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

My bad... Not the 'S' terminal, the 'I' terminal....

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

Here is a wiring diagram showing how Mercrusiser wires the electric fuel pumps on carbed engines.

Re: Elec. Fuel Pump FOUND hanging by on a rope

Re: Elec. Fuel Pump FOUND hanging by on a rope

the entire reason the terminal on the starter solinoid is labeled R is because Resistor Bypass would not fit.

Re: (UPDATE) Elec. Fuel Pump hanging on a rope

Thanks to everyones help thus far, I've learned a lot.

Old Elec. Fuel pump is shot and will need replacing. Shop temp used another, but couldn't get the engine to idel (has been an old problem) they found that the Holley 700 cfm has no idel screws on the metering block, it looks factory sealed. One of the prior owners did this swap. Also found out that there is a newer motor (5.7 Vertec) no hole for mech pump.

I now have a choice of carbs & fuel pumps.

Please advise on your opinion of choice.

Holley 600 or Edelbrock 600 #1409.
Elec. Fuel pump- Carter P4389 or Holley Red
I'm still gonna use the same alum intake. I think it's called a spread bore, one big opening.

Another concern, where to mount the elec. fuel pump. On the stringer (motor mount area) or motor. I did find the old fuel/water seperator w/ bracket, should I mount it on that? and I know about the oil switch situation.

Since both pumps pull, how far should they be from the carb and gas tank?

Thanks again for your help!