Fuel Pump 101

[FlatBoard]

Great follow up on the fuel pump Boofer!! I have a new pump still in the box from MC, and will be returning to my boat next week to install.. Thanks to your thread I am able to handle this myself thus saving me a fortune on labor and a ton of gas not having to tow to the shop. I will print the pictures for an intallation guide and pull apart the old pump to see if it has any of the issues discussed here.

You have a VIP privaleges any time you are in Lake Cumberland!! Just look me up and I will spring for free rides and beverages.

[boofer]

PeterN,

I must caution you about using an aftermarket pump. Just because it may fit does not mean that it is able to meet the demands of your motor. Please be careful!!!

FlatBoard,

Thanks for the kudos. I hope the install goes well for you. Just be real careful with the 12 bolts that go on the module. It took me several minutes to ease each bolt in correctly. Despite the fact that the tank was empty, the bolt holes did not align perfectly. I will take you up on your offer if I find my way to your neck of the woods.

[boofer]

Okay boys and girls, this is getting a little deep.

I finally received a reply from MC. They said that the pump in my old module and in my new module should be the newer turbine style pump. They said that the change was made in the '02-'03 time frame.

So, is it a turbine style pump? I have emailed Carter/Federal Mogul and politely requested that they tell me how to determine if a pump is the turbine pump. I know from calling them that they have an agreement with MC to not reveal any detailed specifications. I am hoping that they will comply with my request since I can simply dismantle this pump and verify which kind of pump it is.

Now, if both pumps are the turbine style pumps, we are back to square one. I have been to the Federated store and spoke with the fellow I mentioned a while back. He has ordered a pump that he believes will work. I am going to try to get by there tomorrow and see what he has. When I showed him the complete fuel module he recognized it minus the top plate which is specific to our boats. He even showed me the filter in his catalog. But, he was unable to draw a specific cross reference based on any of the nomenclature on the pump or the module. The "71-342S" which is on the top plate mimics Carter part numbers (7x-xxx). I am also going to ask him if he can tell if my old pump is a turbine style pump.

I am not feeling any good vibes right now. I honestly think that both the old pump and the new pump are NOT the turbine style pumps. In the back of my mind I am thinking CALS. If it gets to that point, then at least maybe we can finally get some concrete answers and possibly a REAL fix.

[PeterN]

PeterN,

I must caution you about using an aftermarket pump. Just because it may fit does not mean that it is able to meet the demands of your motor. Please be careful!!!

Thanks boofer for the warning, but the only thing a fuel pump does, is pumping fuel - with a specific operation pressure. The MEAT & DORIA pump delivers 3.8 bar (= 55.114 PSI at sea level), which exactly meets the L-18 specs between 53 and 58 PSI. The worst case can be that the pump is not working anymore - this happened twice in 8 month with the genuine Carter pump

[rhsprostar]

PeterN
How did you ever cross reference that pump!? Good work. WHat is the GPH? or LPH? That would be your only other concern regarding capacity other than pressure.

[PeterN]

How did you ever cross reference that pump!?

Hmmmm... I went into a car accessories shop in Salò, Italy (I stay here usually in summer) and tried to find a similar fuel pump in their cataloque.

WHat is the GPH? or LPH?

Honestly: I don't know. But I can't feel a difference in operating, performance or consumption. And last not least: my V8 doesn't sound like a Fiat

[sinister_designs]

GPH = gallons per hour
LPH = litres per hour

it is a very important thing for a engine as starving it of fuel by way of pressure or flow will cause detonation and ultimately engine failure.
Be very careful PeterN.

[JimN]

Also, a high pressure pump won't necessarily push high volume and vise-versa.

[woody]

Thank you for taking on the mantel of 'MC fuel pumps ain't great', ours ran out of warantee a while ago and now is an expensive habit.

This is highly interesting seeing as our 2005 X2 averages 400 - 600 hours before burning out another fuel pump because apparently some of our less attentive club drivers are 'naughty' and let the fuel level drop below 1/4 tank..............

If that were really true of "fuel pumps'' my 400 000 mile Volvo estate would have had a lot of fuel pumps as I do not fill up until almost empty.

If someone really gets to the bottom of this, I would love to know so that we can re-enter the discussion with Mastercraft Great Britain without having to use rude words.
As a Process Engineer in the oil industry that designs the plants that provide the gas/petrol/lpg that runs our boats, being fobbed off "you do not know what you are talking about" is irksome.

I am not posting this in a derogatroy manner - but as a statement of fact that I as a dedicate multi-mastercraft owner believe the firm should be taking in hand and resolving to ensure its status as number one.

[woody]

LPH versus GHP, err there's around 4.54 litres per gallon, erm if that's an imperaial gallon, but as we're an american site it's around 3.5 litres per american gallon I think.

Reason for the difference in between imperail and american gallons is something to do with a tea party in boston perhaps....maybe my elders and betters can correct me.

[JimN]

"The metric system is the tool of the devil! My car gets forty rods to the hogshead and that's the way I likes it."

[PeterN]

GPH = gallons per hour
LPH = litres per hour

it is a very important thing for a engine as starving it of fuel by way of pressure or flow will cause detonation and ultimately engine failure.
Be very careful PeterN.

Hmmmm??? If the pressure is right, in corollary the flow must be right as well. I checked the pressure on this little valve and it had constantly between 3.8 and 3.9 bar (55 PSI) - no matter what rpm or load.

I'll try to find out the flow rate of the MEAT & DORIA pump. What are the GPH/LPH specs for the L-18 ?

[boofer]

Well, I haven't had the time to return to the Federated shop since I got busy with work and "think" I might of fractured a few ribs wakeboarding 3 weeks ago (yeah, it still hurts).

I forgot to ask this guy at Federated about the small disk at the bottom of the module. Does anyone know why it is there? The flow of gas into the bottom portion of the module was definitely restricted by this disk. The module had to be submersed deeper in gas before gas would flow into the area that supplies the pump.

Despite being sidetracked, I will do my best to get us some good information and maybe a fix.

[JimN]

It shouldn't restrict- it's like a check valve that lifts when gas flows into the pump and drops down when the gas tries to flow out again.

[JimN]

Woody- "Apologies any accidental use of sarcasm, cynicism or confusion."

Oy! What's that supposed to mean?