Electric fuel pump replacement

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hgraham
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Electric fuel pump replacement

Post by hgraham »

The hot summer has been a great time to test the health of the fuel system on my new 330. The first day I had it, the electric pump died in my driveway. After giving it the standard thump, it sprang back to life, but I've also had what I think are vapor lock problems when stopped for five minutes or so in traffic. The car will act fuel-starved, then revive when the electric pump is switched on (if I can do it fast enough). I've concluded that the mechanical pump isn't doing so hot either since the car will stall even while driving if it's particularly warm. At the moment, I like the idea of switching to a modern solid state electric fuel pump and keeping the original to rebuild later if originality is desired. However there are a lot of options out there. Are there any recommendations from people who have done this? What are the fuel line sizes for inlet/outlet? What flow rate and/or pressure is needed? Does the mechanical pump have to be bypassed? Could heat from the exhaust combined with a very warm day (90-100F) cause vapor lock or some other failure in the original electric pump?

Hudson
1966 330GT #8553
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tyang
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Re: Electric fuel pump replacement

Post by tyang »

Hi Hudson,

Yes, and yes! The conditions you describe definitely contribute to vapor lock. I think with alcohol in the fuel, and whatever they're adding to CA fuels exacerbates the problem. If you want to make sure there isn't something wrong with your two pumps, both should be rebuilt with new diaphragms with nitrile seals. The push rod on the mechanical pumps should also be measured for movement and the corresponding movement on the mechanical pump and spacer adjusted accordingly. There have been discussions and blog entries covering this procedure.

The mechanical fuel pump line runs under the left headers, and I think it can be affected by excessive heat. As the fuel vaporizes in the steel line, the mechanical pump cannot pull the fuel through the line. The electric pump pushes fuel from the back of the car up the back of the fuel rail so it's a little cooler. The electric pump however is not designed to run for extended periods of time, or at least as these pumps age, they become less reliable.

You can eliminate the electric fuel pump and replace it with a Facet fuel pump for under 60 bucks from any parts supplier. Google "facet fuel pump" and you'll find plenty of options. 3-5psi or "low pressure" pumps are what you want. High pressure pumps will push past the needles in the carbs and flood your engine. To install this pump, you can remove the hard line to the mechanical pump and replace it with a banjo fitting with a barbed end to use soft fuel hoses with hose clamps. Some people have cut into the hard line and attached fuel hose there, but you will have to solder the connections back on when you want to restore this set up. You just need to take a look up there and figure out how you want to install the new pump. The only warning is this area gets very hot since it is right over the left rear muffler. Protect the rubber hoses from this heat to avoid a fire with a shield if need be.

The neatest set up I've seen is when a solid state pump was installed in line with the original pump. The solid state pump is quiet enough that when the car is first started, the familiar fuel pump click is still heard, but the facet pump is running as a back up if, and when, the original pump quits working!

Tom
'63 330 America #5053
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tyang
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Re: Electric fuel pump replacement

Post by tyang »

O.K. Pictures:
Image
Image
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Ed Long
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Re: Electric fuel pump replacement

Post by Ed Long »

I discovered on my PF coupe that the points in the electric pump became corroded when it failed. So, much like the ignition points on my 1967 MGB, I took a piece of fine grit emery cloth after them to clean them, reassembled the unit and it ran fine for another ten years.
Ed
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hgraham
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Re: Electric fuel pump replacement

Post by hgraham »

Thanks for all the helpful advice. I'd certainly love to keep things original, so I guess I'll at least have to check out the electric pump. Does all the fuel need to be drained from the tank to pull the pump or is there a certain level that will keep it ok? I tried to run low on gas in anticipation of needing to pull the pump.

Is there a recommended source for diaphragms with nitrile seals? Did anyone ever come up with a source for any part of the mechanical pump? Is there a solution to the vapor lock problem aside from driving only on cold days? That includes the heat transferred to the electric pump from the exhaust. If the electric pump gets too hot and fuel is vaporizing, would it shut off completely or click really quickly? Since owning the car, I've noticed that the pump has a very rapid click when starting with the engine very warm. The times when the electric pump has failed, the car is very warm and I get no click and no indicator light on the dash.
1966 330GT #8553
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tyang
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Re: Electric fuel pump replacement

Post by tyang »

hgraham wrote:Thanks for all the helpful advice. I'd certainly love to keep things original, so I guess I'll at least have to check out the electric pump. Does all the fuel need to be drained from the tank to pull the pump or is there a certain level that will keep it ok? I tried to run low on gas in anticipation of needing to pull the pump.

Is there a recommended source for diaphragms with nitrile seals? Did anyone ever come up with a source for any part of the mechanical pump? Is there a solution to the vapor lock problem aside from driving only on cold days? That includes the heat transferred to the electric pump from the exhaust. If the electric pump gets too hot and fuel is vaporizing, would it shut off completely or click really quickly? Since owning the car, I've noticed that the pump has a very rapid click when starting with the engine very warm. The times when the electric pump has failed, the car is very warm and I get no click and no indicator light on the dash.
The tank should be drained to about 1/2 of a tank of gas or less. If you open one of the fittings at the rear fuel filter, fuel should drain back into the tank instead of siphoning all over your clothes! While you're there, you might as well change the fuel filter.

The fuel pump rebuild kits sold by the usual suspects should be compatible with modern fuels.

There are a few things to check when you take the electric pump out, but it's worth checking before replacing it with a modern pump.

The check valves for the mechanical pump are useless, but the seals and diaphragm are what you need to use. Take your check valves and change out the seals.

On my car, I noticed that vapor lock happens only when I'm idling at a traffic light. Once I start moving, the mechanical pump works by itself. Does your car run at all on the mechanical pump above 2000 rpm once moving along?

Tom
'63 330 America #5053
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hgraham
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Re: Electric fuel pump replacement

Post by hgraham »

The mechanical pump does fine nearly all the time, except when suspected vapor lock is occurring, just like what you described with your car. It's shut off a few times while in motion, but that was after being stuck in traffic. From what you've described, it sounds like the electric pump is the problem, so I'll address that first. With our California "gas", the seals in the mechanical pump will be my next job.
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DWR46
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Re: Electric fuel pump replacement

Post by DWR46 »

A lot of these fuel problems are related to the fuels today as well as the location of the original electric pump mounting. If you wait until you are stuck in traffic, you will probably be too late to turn on the electric pump, as it will vapor lock, with the resultant rapid 'clicking'. The best way to approach the traffic situation is to either run the electric pump all the time in hot weather, or, as I do, turn the elctric pump on at the first sign of a traffic slow up ahead. If you activate it when you are still at speed, it will usually pick up the fuel and be fine.

I would make one additional comment, actually, the Fispa electric pumps are designed to be used continually. When they are set up correctly, they will run as long as needed. Many of the Ferrari race cars of the 1950s use these along with the MONA rotary (aircraft style)pumps. In period, and in todays vintage races both pumps run all the time. The 450S Maserati uses two FISPA electric pumps along with the MONA pump and we run them all the time with no problems. When we rebuild a FISPA pump. We usually run it on the bench for about two-three hours to verify it will be reliable.
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tyang
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Re: Electric fuel pump replacement

Post by tyang »

DWR46 wrote:A lot of these fuel problems are related to the fuels today as well as the location of the original electric pump mounting. If you wait until you are stuck in traffic, you will probably be too late to turn on the electric pump, as it will vapor lock, with the resultant rapid 'clicking'. The best way to approach the traffic situation is to either run the electric pump all the time in hot weather, or, as I do, turn the elctric pump on at the first sign of a traffic slow up ahead. If you activate it when you are still at speed, it will usually pick up the fuel and be fine.

I would make one additional comment, actually, the Fispa electric pumps are designed to be used continually. When they are set up correctly, they will run as long as needed. Many of the Ferrari race cars of the 1950s use these along with the MONA rotary (aircraft style)pumps. In period, and in todays vintage races both pumps run all the time. The 450S Maserati uses two FISPA electric pumps along with the MONA pump and we run them all the time with no problems. When we rebuild a FISPA pump. We usually run it on the bench for about two-three hours to verify it will be reliable.
Hi Dyke,

I've had my pump run continuously on the bench, but after driving it down to Cavallino a couple years ago, it decided to stop working after about day two!

Tom
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DWR46
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Re: Electric fuel pump replacement

Post by DWR46 »

Tom: The pump would have been fine, except it must have overheard you mention that you were going to a Ferrari meet!!!
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tyang
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Re: Electric fuel pump replacement

Post by tyang »

DWR46 wrote:Tom: The pump would have been fine, except it must have overheard you mention that you were going to a Ferrari meet!!!
I was fighting many fronts to get my 330 America to Florida from NY, so the fuel pump wasn't the only battle, but I made it! I may not have had a fully functioning fuel pump, and only rear brakes, but I was going to damned if I was going to be heading down to FLA on the back of a trailer!
Image

Tom
'63 330 America #5053
365gtc/4
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Re: Electric fuel pump replacement

Post by 365gtc/4 »

Tom
I love that photo. A picture is worth a thousand words. If you have a high res copy can you please email it to me. As an aside that was an epic road trip.
Thanks
John
Failure is not an option. It comes bundled with Windows.
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hgraham
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Re: Electric fuel pump replacement

Post by hgraham »

That photo provides some great inspiration. I'll R&R the electric pump with CA-compatible plastic, use your driving tip of turning on the pump BEFORE a situation arises, and then probably use a lucky rabbit's foot, four leaf clover, or some other such thing until a different major system starts acting up.
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B24Spider
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Re: Electric fuel pump replacement

Post by B24Spider »

Hudson,
Perhaps you'd like to brave the roads with the 330, and join us in Alameda for All Italian Day on October 9?
-Steve
250GT
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Re: Electric fuel pump replacement

Post by 250GT »

DWR46 wrote:A lot of these fuel problems are related to the fuels today as well as the location of the original electric pump mounting. If you wait until you are stuck in traffic, you will probably be too late to turn on the electric pump, as it will vapor lock, with the resultant rapid 'clicking'. The best way to approach the traffic situation is to either run the electric pump all the time in hot weather, or, as I do, turn the elctric pump on at the first sign of a traffic slow up ahead. If you activate it when you are still at speed, it will usually pick up the fuel and be fine.

I would make one additional comment, actually, the Fispa electric pumps are designed to be used continually. When they are set up correctly, they will run as long as needed. Many of the Ferrari race cars of the 1950s use these along with the MONA rotary (aircraft style)pumps. In period, and in todays vintage races both pumps run all the time. The 450S Maserati uses two FISPA electric pumps along with the MONA pump and we run them all the time with no problems. When we rebuild a FISPA pump. We usually run it on the bench for about two-three hours to verify it will be reliable.
Hello Dycke,
Intereseting info on Maserati. 450S,
are you sure about 2 electr pumps by Fispa ?
I ve seen only two Autoflux Mona on those.
I think those below belongs orginal on 300S ,6C ,450S Maseratis
and older Ferraris like Vingale models. 1953, 1954.
Sorry its off topic of course.

Cornelis.
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