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> Hate me, I converted to carbs. Question about priming
surfdogskier
post Oct 22 2019, 02:14 PM
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I finally had my fill of FI and ripped out the entire fuel injection in 30 minutes. I was finally able to clean my engine out nice Installed dual weber carbs. I'm going to hold on to my fuel injection if I ever change my mind or sell.

Question. I installed a new low pressure fuel pump so my lines are empty. When I turn the key, I can't hear it like my FI fuel pump. What is the best way to prime these when they are new?

Everything is hooked up except for the throttle cable. Should I disconnect the fuel lines to get the air out of lines. I do not know if these are vacuumed or not is why I am asking.
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GregAmy
post Oct 22 2019, 02:24 PM
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What carbs?

Is the pump actually running when you turn the key on?

With carbs, when the pump is running it will deliver fuel to the carb float bowls. Any air in the lines will pass through to the float bowls and out of the float valve. Once fuel follows the air then the float bowls will fill with fuel and the float will shut off the flow. A double pump or two on the throttle will result in fuel coming out of the accelerator jets

However, if you wired up your fuel pump where it only runs when the coil is producing power (like the FI does, and is a good safety feature) then you'll have to add a manual switch to turn on the pump to do the above. Or, you wire the fuel pump to also run when you're cranking the engine (the like FI does).
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914_teener
post Oct 22 2019, 02:29 PM
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QUOTE(GregAmy @ Oct 22 2019, 01:24 PM) *

What carbs?

Is the pump actually running when you turn the key on?

With carbs, when the pump is running it will deliver fuel to the carb float bowls. Any air in the lines will pass through to the float bowls and out of the float valve. Once fuel follows the air then the float bowls will fill with fuel and the float will shut off the flow. A double pump or two on the throttle will result in fuel coming out of the accelerator jets

However, if you wired up your fuel pump where it only runs when the coil is producing power (like the FI does, and is a good safety feature) then you'll have to add a manual switch to turn on the pump to do the above. Or, you wire the fuel pump to also run when you're cranking the engine (the like FI does).



On crap....we're back to wiring again. Have to put the FI back on (IMG:style_emoticons/default/av-943.gif)
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porschetub
post Oct 22 2019, 02:33 PM
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No need to remove lines,if setup right it will self prime after cranking for a while ,have you wired the pump via SirAndys method in the info section ?.
Pull your negative from the coil and crank over using a remote starter switch or second person on the key,you can check for leaks than way...safer than when its running.
Good luck.
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ndfrigi
post Oct 22 2019, 02:42 PM
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I think you just used the stock wire for fuel pump but did not do some modification to get power supply to that fuel pump wire. FI will give the power supply to that wire.
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surfdogskier
post Oct 22 2019, 03:11 PM
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I did not change the setup with the wires to the existing fuel pump. I used the same ones I had in my high pressure pump from the fuel injection.

I just don't hear this fuel pump like I did my other fuel pump.
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rhodyguy
post Oct 22 2019, 03:47 PM
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What type of pump did you install? Rotary or facet? It doesn't take much to build 3ish lbs of pressure. The rotarys are very quiet. With the key on, not running, operate the linkage fully by hand a few times while looking down the carbs for fuel exiting the pump jets.
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Rand
post Oct 22 2019, 03:54 PM
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The pressure is VERY different. Like 30psi vs 5. Hopefully you swapped appropriate pumps. Glad you saved it because learning and understanding FI is so worth it.
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surfdogskier
post Oct 22 2019, 04:03 PM
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QUOTE(rhodyguy @ Oct 22 2019, 05:47 PM) *

What type of pump did you install? Rotary or facet? It doesn't take much to build 3ish lbs of pressure. The rotarys are very quiet. With the key on, not running, operate the linkage fully by hand a few times while looking down the carbs for fuel exiting the pump jets.

I don't know which but it is suppose to produce 3.5lb max. Got from Pelican but it is CB Performance pump. I will give try pumping the linkage and see if I get anything. Nothing so far.
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surfdogskier
post Oct 22 2019, 04:06 PM
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QUOTE(Rand @ Oct 22 2019, 05:54 PM) *

The pressure is VERY different. Like 30psi vs 5. Hopefully you swapped appropriate pumps. Glad you saved it because learning and understanding FI is so worth it.

Oh I know that. It is definitely 3.5lb psi. I did the swap to start driving. After ripping everything out, it has to be my wiring harness or MPS or both was my problem. Every other option was exhausted. Dr914 offered to check my MPS which I will mail to him.
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rhodyguy
post Oct 22 2019, 04:12 PM
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If not done do Andy's ground wire between the relay board and chassis mod. The board relay And fuse need to be place. If only to get it running. the pump will be activated continuously but stop running after the pressure builds. 3 full pumps and a bit of throttle feathering it should come to life. Did you get the CB Weber book when you bought the pump?
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Rand
post Oct 22 2019, 04:16 PM
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"Dr 914" is here to sell you parts. You are already on this forum, he should just answer up instead of asking you to mail him stuff. Why do you think you need an MPS with carbs? And why would a self proclaimed expert ask you to send him an FI part to troubleshoot your carb problem?
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bbrock
post Oct 22 2019, 04:16 PM
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QUOTE(surfdogskier @ Oct 22 2019, 03:11 PM) *

I did not change the setup with the wires to the existing fuel pump. I used the same ones I had in my high pressure pump from the fuel injection.

I just don't hear this fuel pump like I did my other fuel pump.


I think this is your problem. Go back to what @ndfrigi said in post #5 and then look at this article: http://www.914world.com/specs/SirAndyCarbFuelPumpRelay.php The ECU for the FI is what turns the stock pump on. With that gone, you have to do the simple mod to get your fuel pump relay to kick on.
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surfdogskier
post Oct 22 2019, 04:18 PM
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QUOTE(bbrock @ Oct 22 2019, 06:16 PM) *

QUOTE(surfdogskier @ Oct 22 2019, 03:11 PM) *

I did not change the setup with the wires to the existing fuel pump. I used the same ones I had in my high pressure pump from the fuel injection.

I just don't hear this fuel pump like I did my other fuel pump.


I think this is your problem. Go back to what @ndfrigi said in post #5 and then look at this article: http://www.914world.com/specs/SirAndyCarbFuelPumpRelay.php The ECU for the FI is what turns the stock pump on. With that gone, you have to do the simple mod to get your fuel pump relay to kick on.

I was just coming up to ask that.....My fuel injection harness is gone so I probably have no power to my fuel pump. Thanks for the info! I will look that up.
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Rand
post Oct 22 2019, 04:26 PM
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I still want an explanation to why MPS was even brought up regarding a carb conversion.
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rhodyguy
post Oct 22 2019, 04:33 PM
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Yes. No pump power right now.
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porschetub
post Oct 22 2019, 04:47 PM
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QUOTE(surfdogskier @ Oct 23 2019, 10:11 AM) *

I did not change the setup with the wires to the existing fuel pump. I used the same ones I had in my high pressure pump from the fuel injection.

I just don't hear this fuel pump like I did my other fuel pump.


Don't believe that will work as the jumper lead (earth) you will need to fit to body as per that DIY supplies power that would normally be covered by the FI harness which you no longer have,reason you don't hear the pump.
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surfdogskier
post Oct 22 2019, 04:48 PM
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QUOTE(Rand @ Oct 22 2019, 06:26 PM) *

I still want an explanation to why MPS was even brought up regarding a carb conversion.

It was an issue with the FI I was having. Has nothing to do with the carb setup.
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surfdogskier
post Oct 22 2019, 04:53 PM
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Ok, I connected the 4 pin to the ground as mentioned per the sirandy info and now when I turn the key, I hear the pump. Now I have gas but trying to crank her, I have flames in one or both the carbs. A little scary. She won't start but I'm not pushing her. Only got my 10 year old daughter turning the key as I play with the throttle.

Are the jets not spraying is my only idea?
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bbrock
post Oct 22 2019, 05:58 PM
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Did you set the float levels on both carbs when you installed them? First thought is that maybe the float valves aren't shutting off fuel when the bowls are full. Beyond that, I'll leave it to those who actually know something about carbs.
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