New owner / Fuel Pump

[hgraham]

Hello to everyone on the forum. I've been following along for a while in anticipation of delivery of my first Ferrari, a 1966 330GT. Well it finally arrived yesterday! As soon as the shipper had it off of his truck and idling at the curb, I hopped in and took it out for a 15-20 minute romp through the back roads... loads of fun. As I pulled back into my driveway, it sputtered and stalled. I though I'd probably let up on the clutch too fast and didn't give it a second thought until I went out to start it this morning and had only the slightest hint of a start. Remembering what I've read here, I flipped the "A" switch to turn on the electric fuel pump, but heard nothing. Uh-oh!

While I've read that the mechanical pump can work on its own, it wasn't doing so at the moment, and I'd rather have the electric pump working anyway. I got out the electric tester and started checking everything I could find, reading through the message board at the same time to find similar problems. I checked the fuses first, but all looked OK. As suggested by Kerry in another thread, I checked that the brake lights functioned, since they are on the same fuse, and they did. I pulled out the switch to make sure the wires were connected, then disconnected them and checked switch function (OK) as well as power to the switch. The single wire had ~12V and the lead with 2 wires read 0V, which I figured was OK since the two should be going to the fuel pump and the tach indicator light. I then tried to connect the switch wires directly to see if the pump and/or indicator light would come on but had no success. So... what should I check next? I'm not sure how to check power to the electric pump.

[tyang]

Hi hgraham,

Welcome to the board and the ownership of a 330! Congratulations. You're certainly being initiated in classic Vintage Ferrari Fashion!

The indicator light could be burned out, but the other wire should head back towards the fuel pump which is located in front of the left rear wheel by the frame rail. You'll need to jack up the car and look above one of the mufflers. A stock fuel pump looks like this:

12 volts to the stud on the top should get it to work, and sometimes a light tap will get it to work. Two of the most common problems are burned points or a brittle diaphragm. You can remove the cap (don't break it!) and file the points with a points file, but the diaphragm issue requires pulling the pump.

Let us know what you find.

Tom

[hgraham]

Just checked the voltage at the top of the fuel pump and it's not getting anything. So it seems that I'm missing something in my other tests, although I've done each several times.

[hgraham]

Just kidding. I didn't have the key switched on when I tested it. It now shows around 10.5V at the pump. I checked the battery leads and it's just over 12V, so maybe the current is just too weak?

Hudson

[kare]

Among first things to check is also how oxidized the fuse & fuse holder is. It may pass current to lit a light bulb, but not enough to wake up the diaphram pump.

So just because it is easy: replace the fuse and roll it a little to be sure it makes a proper contact. Have a look at the wires too, an oxidised wire held down by an oxidiced screw may also limit the passing on of electric current.

If you end up testing the pump by feeding current directly to the plus wire, use the battery not a battery recharger. Most rechargers don't provide enough current to wake electric components up; you can guess how many electric components I took apart and reassembled before figuring this one out...

And yes; be carefull with that cover!

Best wishes, Kare

[hgraham]

Kare: an excellent suggestion, thanks! The fuses look like they might have been installed by Enzo himself, so I'll be stopping by the auto parts store tonight to pick up replacements.

After testing the current to the fuel pump, I noticed that the purple indicator light now comes on when I flip the A switch. I must have made a better contact. However, the pump still makes no noise. The car was started and driven several times to jockey its position on the transporter (Intercity Lines), and the driver, who has no doubt started many vintage Ferraris, commented that mine was about the easiest one he'd ever started. With it having run so recently, the glass fuel bowl is full. Would this normally cause the electric pump to shut off?

After the auto parts store, I'm also going to pick up 5 gallons of gas just to eliminate the possibility of an empty tank.

Hudson

[hgraham]

I just got back to the car after work. I didn't get a chance to pick up a fuse, but I did add 5 gallons of gas to the tank, which registered on the fuel gauge and had no effect on the car not starting. I took off the air filter assembly to check if the carbs are getting fuel and they're bone dry. Manually operating the carb lets in the faintest spurt of gas or none at all. Since the fuel bowl is full, does this mean that there is a blockage between the fuel pressure regulator and the carbs? Or is there just not enough pressure because the electric fuel pump is not working?

Hudson

[tyang]

I just got back to the car after work. I didn't get a chance to pick up a fuse, but I did add 5 gallons of gas to the tank, which registered on the fuel gauge and had no effect on the car not starting. I took off the air filter assembly to check if the carbs are getting fuel and they're bone dry. Manually operating the carb lets in the faintest spurt of gas or none at all. Since the fuel bowl is full, does this mean that there is a blockage between the fuel pressure regulator and the carbs? Or is there just not enough pressure because the electric fuel pump is not working?

Hudson

Hi Hudson,

The electric pump pushes fuel from the rear of the fuel rail, so even if the glass bowl is full, fuel can still drain back from the back of the fuel rail. If the the engine was hot the last time it ran, the fuel could have evaporated out of the fuel bowls, and left your carburetor bowls empty. Without the fuel pump working, you won't get enough fuel to fill the carb bowls to squirt the accelerator pumps. If you're getting voltage to the pump, and there's no clicking, I would look there. Low voltage could arc out the points, but you're still going to get under there and find out why the pump isn't working.

Tom

[hgraham]

After cleaning the fuse clips and wire leads, inserting a brand new shiny fuse, and giving the fuel pump a thump with a wrench, it came to life very nicely. I got to enjoy the longest drive yet in the car and will be smiling about it for the rest of the week. Meanwhile I'll try to figure out what's going on with the fuel pump by reading through the message board. The car did sit for a very long time before being "mechanically refreshed" by the previous owner. Could the pump just have been a little groggy or is the need to tap it back into action a signal of impending failure?

Thanks to everyone for the help so far. Although the car is certainly beautiful to look at, it's a lot more fun to drive.

Hudson

[tyang]

Hi Hudson,

The two common problems are the diaphragms get stiff and the points get dirty.

Tom