Fairlane56
Member
1 week ez start on mine. 2 weeks 3-5 pumps and hope it catches, 3 weeks or longer crank 15-20 seconds or remove air cleaner and add fuel in carb bowl. I blame the ethanol blend fuel…. Worse in California with summer blend.
1954 Mercury Fuel Issue
- Thread starter JMFL36
- Start date
KULTULZ
Well-known member
Dave is correct in his description.
Here is another problem(s) with just a primer pump -
1) The pump needs a filter in front of it so as not to ingest any fuel tank trash and lock/burn it up ...
2) A mechanical pump does not like inline filters on the suction side and can lead to vapor lock/ fuel blend separation, etc.
3) The pump is going to draw a lot of AMP and the OEM IGN SW and wiring is not going to like it. You need a BAT RELAY FUSED source and sufficient wire gauge to get AMP to the pump.
4) The pump should be on a by-pass circuit as shown below. The install is not correct as there is no ELECT PUMP INLET FILTER installed.
And of course I cannot find the ILL ...
... i'll be back ...
OK ... I am back ...
Here is another problem(s) with just a primer pump -
1) The pump needs a filter in front of it so as not to ingest any fuel tank trash and lock/burn it up ...
2) A mechanical pump does not like inline filters on the suction side and can lead to vapor lock/ fuel blend separation, etc.
3) The pump is going to draw a lot of AMP and the OEM IGN SW and wiring is not going to like it. You need a BAT RELAY FUSED source and sufficient wire gauge to get AMP to the pump.
4) The pump should be on a by-pass circuit as shown below. The install is not correct as there is no ELECT PUMP INLET FILTER installed.
And of course I cannot find the ILL ...
... i'll be back ...
OK ... I am back ...
Attachments
Last edited:
paul2748
Well-known member
You don't need a by-pass circuit - just a electric pump that has a flow through feature.
See https://www.ctci.org/vapor-lock-and-electric-fuel-pumps/
See https://www.ctci.org/vapor-lock-and-electric-fuel-pumps/
Last edited:
KULTULZ
Well-known member
That is why a PRIMER PUMP should be on a BY-PASS CIRCUIT.
One must ascertain FLOW-THRU RATING before purchase of the pump. On a BY-PASS, there is no need for a FLOW-THRU RATING.
JMFL36
Senior Member
I don't see the need to put the auxiliary electric pump on a by-pass circuit. The pump I bought is flow-thru and my stock mechanical pump pulls like a clydesdale. I'm going to use a momentary switch wired to a battery power source, which eliminates the need for a relay and for wiring through an oil pressure switch and the ignition circuit. Just a simple flow-thru primer pump with 2 wires, ground and power through a momentary toggle switch (with an in-line 3 amp fuse).