Using 3-outlet fuel pump om 1974

montelatici · #1 (**permalink**) 01-05-2004, 06:34 PM

As part of a larger acquisition I am receiving 2 ea. three outlet pumps. My two outlet pump is marginal (light goes off sometimes but is on 90% of the time). I want to try these pumps (from two 76 cars) to see if either is better than my two outlet pump. Questions?

Which is the by-pass outlet on a three outlet pump?

What is the best way to block the bypass outlet?

Thanks,

Alfredo

montelatici · #2 (**permalink**) 01-05-2004, 06:36 PM

Oh, I changed both filters. Prior to changing them the light was on constantly.

Alfredo

**Roadtrip** · #3 (**permalink**) 01-05-2004, 07:04 PM

The large diameter port is for the intake from the fuel tank. I believe the center port is the outlet port, and the other small port on the end is the PRV. I suppose it would be easy enough to check by installing the pump with a long hose from the small end port going into a can. Turn the pump on. If no fuel comes out the hose, then that's the PRV (assuming the rest of the system is functioning correctly).

As far as capping the line off, I would guess that a short piece of hose with a shoulder bolt clamped in the end would do the trick.

That said, I'm not a big fan of used supply pumps from unknown sources. I've got a couple of used pumps that were either broken outright (leaked) or only lasted a couple of months. With something as critical as the fuel supply pump, I'd recommend just getting a new Bosch L-Jetronic supply pump and modify the restrictor outlet to 1/16th inch . . . . . . . and not worry about when the old pump is going to leak or quit . . . . . because it probably will.

montelatici · #4 (**permalink**) 01-05-2004, 07:32 PM

Thanks John. Since these pumps were actually at no cost to me, I'd like to give them a try before I buy a new pump. Actually, there was a fellow that had a two outlet pump that needed a 3 outlet pump. Maybe I should search the archive and ask him if he wants to trade pumps. But if I bought a new Jetronic pump, how do you restrict it?

Alfredo

**Roadtrip** · #5 (**permalink**) 01-05-2004, 07:58 PM

The L-Jetronic supply pump doesn't put out quite the volume of the old pumps, so..... you have to make the existing restrictor in the Outlet fitting of the SPICA injection pump a tiny bit smaller (1/16th inch diameter drill). Just disconnect the outlet hose to the injection pump, screw off the fitting and you'll see it looks like this underneath. Clean it up real good so solder will stick to it, then just melt some electrical solder to plug up the existing hole (it's about 3/32nd", I think) and redrill with a 1/16" drill. This sounds like a small change, but it will make about 5 psi change in the pressure that the supply pump will hold in the line. With an L-Jet supply pump and a 1/16" restrictor, you'll get 10 psi on battery only and 15-18 psi with the alternator. Without the restrictor you may or may not get the low pressure light (7psi) extinguished on the battery. I have a L-Jet supply pump on my car and it works like a champ and is inherently much more reliable than the old pumps.

The only other mod you'll have to make for the installation is making the diameter of the pump a little bigger with some rubber or something so the bracket will grip it well, and use ring connectors instead of the spade connectors (or put spade connectors on the ring terminals and use the stock wiring).