Fuel System: Using an Electric Fuel Pump on an R2 Avanti

[SILENTBOB]

Currently, the car has a stock fuel system from fuel tank to carburetor. The issue is hard starting when the car sits for a long time and the fuel bowls have "dried out".

I have a flow through electric pump ready to install. The question is - do I take the existing mechanical pump out of the fuel circuit so just the electric provides the fuel to the carb full time or do I use them both in series using the existing fuel lines from the back of the car to the mechanical fuel pump with the electric used momentarily pushing fuel through the mechanical pump just to fill the carb fuel bowls for an easier start.

My concern is the diaphragm in the mechanical pump getting damaged or blown out by the pressure from the electric pump. Also, I'm not sure if the electric pump will work as the full time pump with the R2 setup given the mechanical pump has equalized pressure with the supercharger.

Thanks for the help.

[Mike]

Dribble a litle gas into the flapper valve on the carb hat, if the car has been sitting. Drive it more often!
Mike M.

[PackardV8]

Hi, Bob,

Either way, full time or as a primer, will work. Most electric pumps don't produce enough pressure to damage a healthy diaphragm. The exceptions are racing and EFI pumps, but you probably aren't considering one of those.

If you prefer, you can wire your electric pump to a "momentary on" pushbutton to prime the mechanical pump or wire it to the starter circuit so it only pumps while the starter is engaged.

jack vines

[sbca96]

After my recent R1 fuel pump rebuild failed, I have decided to take it out of the loop
and use the electric pump I bought years ago for my Hawk. My plan is to put it onto
the frame rail, with the original restriction fitting and return plumbing. I have had it
with the old mechanical pumps. No more sucking oil from the crankcase, or pumping
fuel into the crankcase, or pumping oil out the vent ... its days are numbered.

Tom

[SN-60]

I agree with Mike,--- My Avanti has the same problem if it sits to long ('63 R-2) but the R-2's are so easy to prime through the flapper valve, it's never been a big concern. If Your mechanical pump is in good condition,
I don't think You should even think about adding an electric fuel pump. Make sure the carb accelerator pump is working at 100% also.

[Lenny R2]

I installed a electric fuel pump on my R2 for just the same reason,hard starting when sitting a few weeks.
I mounted it near where the gas hose comes out of the tank & have a push button under the dash.

[WCP]

Bob, an electric "primer" pump beneath the fuel tank is the way to go. Turn the ignition key to "Acc" and push the momentary switch under the dash for a few seconds then turn to "Start" - engine fires immediately. I add a further refinement in the form of a fuel tank "cross-over" solenoid beside the electric pump with a by-pass line that includes a petcock shut-off. The solenoid is wired to the "Acc" side of the switch thru a hidden toggle switch. This cuts the fuel supply when the ignition is off, and provides a means of theft prevention when the toggle switch is flipped off. The by-pass line with petcock is there in case the solenoid fails.
I know from experience that if I've "toggled-off" and forget to turn it back on, the car will go about 100-200' and die. I used this system on my 1st R1 Avanti in the mid 80's and have it currently on my R2 Avanti. I consider this a safety upgrade for the Avanti.

[SN-60]

I think we're trying to re-invent the wheel here guys!!!

[SILENTBOB]

I would like to thank everyone for their recommendations.

At this point I plan to install an Airtex 110-E8090 http://www.summitracing.com/parts/ATX-E8090/ as a replacement for the mechanical pump.

Does anyone know what block off plate can be used when the mechanical pump is removed?

[sbca96]

Does anyone know what block off plate can be used when the mechanical pump is removed?

I believe Mr Gasket makes a perfect match, but its chrome.

Tom

[jlmccuan]

How will you boost reference pressure on your R2 with only the electric pump?

[SILENTBOB]

I believe Mr Gasket makes a perfect match, but its chrome.

Tom

Which engine is it for? Chevy, Chrysler, Ford?

Chrome is ok - black paint will make it look stock.

[SILENTBOB]

How will you boost reference pressure on your R2 with only the electric pump?

It shouldn't cause a problem as the car is never pushed to the point of positive pressure from the supercharger.

[sbca96]

Which engine is it for? Chevy, Chrysler, Ford?.

Not sure, its on the rack at Oreillys, I saw it a few days ago. Regular stocked part.

Tom

[64studeavanti]

I have a Mallory pressure regulator part #4309 that has a port for the blower.