I’ll report back once I get that done but it’s probably going to take a while with all this stupid corona stuff happening
Ford 300 new fuel pump problems
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Ford 300 new fuel pump problems
I just installed a new mechanical fuel pump about 2 weeks ago on my 300 and I’ve had issues with it cutting out on fuel but when I let it sit for about 20 minutes it’s fine again. Any suggestions on what it could be? I was thinking that just gave me the wrong pump or a defective one but that seems to easy of a fix lol.
FTE Legend
Joined: Nov 2015
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From: Angier, NC
What year truck we working with here?
Are you sure it is running out of fuel?
Next time it happens pull the air filter open the choke and looking down into the carb move the throttle do you see gas squirt?
If so it is not a fuel issue.
Report back what you find.
Dave ----
Are you sure it is running out of fuel?
Next time it happens pull the air filter open the choke and looking down into the carb move the throttle do you see gas squirt?
If so it is not a fuel issue.
Report back what you find.
Dave ----
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It’s a 66 f100 and it won’t squirt fuel out of the carb, I’ve also tried taking the fuel line off the carb and turning it over to see if anything would come out and sure enough there was nothing. 10 minutes later I hook everything back up and try starting it for a minute straight and nothing so I checked the carb after that and then the fuel started to squirt out the carb again and it fired right up
Fleet Mechanic
Joined: Nov 2002
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It is not unheard of for the rubber fuel line connections to de-laminate inside and seal itself shut. Replace all the rubber fuel line connections from the tank forward. Also pull the sender and replace the sock over the pickup.
Post Fiend
Joined: Apr 2002
Posts: 19,311
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From: Waterloo, Iowa
Those hard lines can get crud built up in them. It's not a bad plan to backflush it with some shop air. Don't go crazy and hit it with 150 psi, but make sure the line isn't obstructed. Then there's a couple rubber hoses that provide protection against breakage due to frame flex or vibration - one usually right where the line connects to the fuel pump, but also another one underneath the cab, where in-cab fuel tanks were used. Point being any rubber hose (and clamps) need to be replaced, they can leak a tiny bit of air and the pump will shut down. The fuel tank pickup tube can get pinholes too, this will cause headscratching. Make sure any replacement fuel pump is tested for fuel pressure output, they can be all over the place. Any mechanic's vacuum gauge can do this in about 30 seconds.
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All the line in my truck is metal until it gets to the engine bay but sometimes I hear somethin clicking around in the fuel tank so maybe the new fuel pump is working so much better that it’s picking some crud from the fuel tank haha
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So I put new rubber lines on it and tightened down the fittings on the fuel pump all the way and when I took it for a test drive it did the same ****, I drove it for about half an hour and when I get up to 60mph+ it starts to jump like it’s trynna do a burnout and if I put my foot down all the way when it gets to 60 it just dies and but turns right back on when I let out the gas. All the other gears are fine when accelerating it’s just when it’s about 3500 rpm in 4th (I got a 268 comp cam so it can get up to 5200 rpm)
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Post Fiend
Joined: Apr 2002
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From: Waterloo, Iowa
It's a good idea when replacing a fuel pump to test the pressure output, and the volume output. Good idea during a Tune-up, too.
Carburetors only need maybe 5 psi. More is not better in a stock engine. A mechanic's vacuum gauge will test pressure in about 30 seconds, the engine doesn't even need to be running.
Then, if the pump output is within limits, set the carburetor float height to spec according to the book. The goal here isn't so much the float height as it is we want to see that the fuel height level in the bowl is at the factory spec after a few minutes idling on level ground. The entire carburetor is calibrated from the factory on a specific fuel height in the bowl being maintained within 1/32". Adjust the float height up or down as required to get the fuel height in spec.
When all that's straight, ignition timing straight, no vacuum leaks, etc. the carb will likely dial in just as easy as pie and purr. Too high or too low fuel level, either will cause big problems. New esp. imported fuel pumps aren't known for being very good these days.
Carburetors only need maybe 5 psi. More is not better in a stock engine. A mechanic's vacuum gauge will test pressure in about 30 seconds, the engine doesn't even need to be running.
Then, if the pump output is within limits, set the carburetor float height to spec according to the book. The goal here isn't so much the float height as it is we want to see that the fuel height level in the bowl is at the factory spec after a few minutes idling on level ground. The entire carburetor is calibrated from the factory on a specific fuel height in the bowl being maintained within 1/32". Adjust the float height up or down as required to get the fuel height in spec.
When all that's straight, ignition timing straight, no vacuum leaks, etc. the carb will likely dial in just as easy as pie and purr. Too high or too low fuel level, either will cause big problems. New esp. imported fuel pumps aren't known for being very good these days.
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So turns out it was the fuel pump and I did some research and apparently all the oem ones are **** and I just ordered a jegs competition performance fuel pump, it gives a max of 14 psi but it comes with a regulator and I also ordered a fuel pressure gauge and oil pressure shutoff switch. I’m pretty excited to do this because now I can see how much psi I’m getting and control it also. The only thing I’m scratching my head on is if I can mount it in the engine bay. I got the tank in the cab so it doesn’t have to travel too far and I read that it has to sit lower than 18 above where the bottom of the fuel tank is and I’m good on that. And I’m not too concerned about vapor lock because it’s an in-line 6 and the exhaust is on the other side so it shouldn’t get that hot there. I would mount it under the chassis but it’s all metal pipe there.
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(Hopefully) final update! I just got the new jegs electric fuel pump in and it’s working like a dream, I’ve never had it drive so smooth and it felt like a Cadillac when I did a rolling burnout for 50ft😂. I highly recommend doing this to your carbed 300
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