Electric fuel pump revisited

[squonk 41,104]

Ever since I have owned my C-160 (3 years now), I've had fuel issues. From running out of gas and not re-priming to vapor lock and raw fuel smell in my garage. Last year I installed an electric pump,( Napa # 610 1051) but had issues with fuel running out of the carb after shut off.

 

I tried a fuel pressure regulator but the piece of crap failed and caused he tractor to not run at all. I switched back to the mech. pump and installed a spare carb. that I rebuilt. Lately I've been having starting problems and fuel leaking from somewhere on the engine and leaving a puddle. Problem was, it would be fine one day and a problem the next. Finally yesterday I was able to catch it in the act of doom! I turned the gas on at a shut off I installed after the filter and fuel started running out of the back side of the pump. That pump is junk. I have a plastic one but I really don't want to install it so close to a hot muffler. I still had the electric pump mounted so why not try again.

 

I mounted the pump on the hood stand. I have 12V power coming from the coil when the switch is on. I have a 5A fuse inline going to a standard 5 pin relay. I took the auto start out of a car a while back and there were 32,498 of these relays under the dash!

 

Pump and relay mounted;

 

My fused connectors. The one from the battery came with my battery tender. Power from the battery goes thru a 10A fuse to the relay. When I want to use the tender I unplug the pump power and connect the tender.

 

Switch power comes from the ign. coil to the coil in the relay with a 5A fuse.

 

Area under pump where fuel was literally running out. Not nice next to a hot muffler.   Fuel was running down stained area of the block.

 

With engine running pump was drawing between 3-8 amps. Meter was jumping all over. It was tough to get a good reading. Important thing to know with a 15A alternator

 

Ammeter with lights on and at full throttle. Lights off and at idle showed a slight discharge

 

Engine runs good with no issues with fuel leaking after shutoff. I'm not happy about the amount of amperage it takes to run the pump but we will see what happens. Glad I ran power through a relay instead of right from the switch.

 

 

[can whlvr 993]

very interesting,my 160 doesnt start good if it sits for a while,i know its a week fuel pump,i even put the same fuel shut off as yours but it didnt help.once shes running she runs perfect though

[JC 1965 1,530]

Mike, Do you know the amp rating on the relay that you used ?  I saw some 12 volt 30 amp relays on ebay that were really cheat, will they work for wiring the electric fuel pump ? I have my electric fuel pump wired through the ignition switch but after reading your post, I want to get a relay. I didn't know the pump would require that much amperage.     Any help appreciated.  

[squonk 41,104]

Most Automotive relays are rated at 20 or 30 amps. The one I used is 30. They are real common used in a lot of cars usually multiple times in he same car. If you have a "Pull your own part" auto salvage yard near you, You can cruise thru the GM, Ford or Dodge lot and yank out an A/C relay and you'll be good to go  for a couple of bucks. Most of them have the terminal and wiring schematic right on them.

Edited March 5, 2013 by squonk

[squonk 41,104]

Here are some pics of the std. automotive relay. The wire diagram is as follows. You supply 12V power from a switch to either terminal 85 or 86. The terminal you don't supply power to goes to ground. You can see a picture of a coil in series between 85 and 86. That is the relay coil that pulls in the relay contact. You use a 5 amp fuse for that. You supply battery power to terminal 30 and fuse that supply with a 10 amp fuse. You connect the pump to terminal 87. and ground the pump. When you turn the power on the coil energizes and pulls the relay contact from 87A to 87 and the pump runs.

 

The terminals are marked on the bottom.

[JC 1965 1,530]

Thanks Mike, That is exactly what I needed.       I appreciate you taking the time to explain this to help me out. And the pics. are really icing on the cake. Many thanks !!  

[SousaKerry 501]

I have a similar pump and I am ashamed to admit I did not use a relay and just hooked it up to the ignition relay.  So far it works good but I still have problems starting the engine (KT-17 II) if it sits more then a week.  I think my next step is to find a small check valve to put in the line just before the carb. 

 

Although I may just have a float issue.

[JC 1965 1,530]

I have a similar pump and I am ashamed to admit I did not use a relay and just hooked it up to the ignition relay.  So far it works good but I still have problems starting the engine (KT-17 II) if it sits more then a week.  I think my next step is to find a small check valve to put in the line just before the carb. 

 

Although I may just have a float issue.

 

This might help !!  Before I try to start my engine I turn the key to the on position ( you can hear the pump running ) Wait A few seconds and then turn key to start and engine should start. That gives the pump time to fill the carb with gas. It works for me , Hope it helps you !!  

[squonk 41,104]

I put a fuel shut off right after the pump. If the fuel wants to siphon back to the tank, the shut off will stop it. I just need to remember to turn it back on when i want to start the engine.

[TT-(Moderator) 1,131]

inline one-way check valve

[JamesBe1 82]

I have a similar pump and I am ashamed to admit I did not use a relay and just hooked it up to the ignition relay.  So far it works good but I still have problems starting the engine (KT-17 II) if it sits more then a week.  I think my next step is to find a small check valve to put in the line just before the carb. 

 

Although I may just have a float issue.

 

This might help !!  Before I try to start my engine I turn the key to the on position ( you can hear the pump running ) Wait A few seconds and then turn key to start and engine should start. That gives the pump time to fill the carb with gas. It works for me , Hope it helps you !!  

 

Yep, I have mine hooked up the same way.  All I do is wait a couple of seconds for the pump to change pitch signaling that the carb bowl is full, and it usually starts pretty easily.  If there is any shame for doing it that way, then I guess I deserve it too.

[Audioshot 2]

I thought about installing an electric fuel pump (Posi-Flo 610-1051) to eliminate the long cranking when starting my 310-8 for the first time every week.  Once it fires, it runs great.  My two questions are:  what are the disadvantages of wiring one without a relay (direct)?  Has anyone tried an inline primer bulb like they sell at a marine supply?

[Audioshot 2]

So I installed an inline primer bulb I bought at West Marine for $20.  After one or two squeezes the machine fires up immediately.  Success!

[SousaKerry 501]

I do leave the key on before cranking and wait for the pitch to change but to no avail. 

 

I'm waiting for warmer weather to mess with it again,  that and my little rangers(Ford and Wheel Horse) are taking up all my time lately