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11-02-2015, 01:04 AM | #1 |
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Join Date: Sep 2014
Location: Toms River, NJ
Posts: 437
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Possible fuel pump issue
Last year when I bought my truck it had a 110gph Holley mechanical fuel pump on it. About a month after driving it, the fuel pump went bad, so I bought another of the same (http://www.summitracing.com/parts/hly-12-327-11). Shortly after I spun a rod bearing and pulled the motor.
I bought another used gen 1 sbc 350. I put the Holley fuel pump I had bought on, which has probably around 500 miles on it, give or take. The fuel pump has sat for about 11 months or so while I was working on the truck. I finally got the motor, trans, etc. all hooked up and I'm getting no fuel to the carb. I poured about 3 more gallons of gas into the tank, which was close to full when I parked it. I unhooked the line between the fuel filter and the pump and made sure there's gas there and it seemed to be under some pressure (after cranking the motor). I removed the pump and pushed the lever, which I could hear a sucking noise coming from the pump when I pushed it in. The spring is super tight though and it was very hard to push. I made sure the pump was against the pushrod when I bolted it in. My fuel lines and tank were all replaced within the last 2 years so they shouldn't be the issue at all. I tried cranking the motor with the fuel line going to the inlet on the pump and nothing on the outlet, to see if I could get fuel pushing out, and nothing happened. Is my fuel pump bad? Are there any other things I can do to try and make it work? I really don't want to drop another $100 on a fuel pump. My motor shouldn't be making over 300hp/tq. What size pump do I really need? Please help, I just want to get my truck back on the road. |
11-02-2015, 09:52 AM | #2 |
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Join Date: Aug 2009
Location: Bowser
Posts: 13,732
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Re: Possible fuel pump issue
Pull the fuel line off the pump suction, put it in a pail, pop the cap off the tank and let it flow.
You should get a steady strong flow if there are no restrictions. If there's poor flow and If there's a filter on the fuel line before the pump, remove it. If you have good inlet flow you should be good. If it still won't pump then temporarily remove the filter between the pump and the carb. Also try holding the choke completely closed while cranking. The vacuum sometimes will help pull fuel into the carb. |
11-02-2015, 12:20 PM | #3 |
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Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
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Re: Possible fuel pump issue
Could possibly be the fuel pump. Do the test mentioned by geez. If you still don't get any fuel out of it (at least 1 pint in less than 30 seconds) work yourself backwards.
Remove the hose from tank to the fuel pump and replace with a 2-3 foot section of fuel hose on the inlet side. Place the other end in a one gallon container of gas placed under the truck. If engine starts and runs okay than the line from the tank is either clogged or the fuel filter inside the tank is clogged.
__________________
68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive... |
11-05-2015, 01:00 PM | #4 |
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Join Date: Sep 2014
Location: Toms River, NJ
Posts: 437
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Re: Possible fuel pump issue
Ok, I finally got out to check it out. Due to the positioning of everything, it would be a huge PITA to disconnect the inlet line to the pump without removing the pump first, and I really don't want to do that. I figure start with the easiest and work up.
I have a filter between the tank and the pump. I disconnected the line before the filter and had no fuel coming out. Then I hooked up my mightyvac to the line and gave it a couple pumps. after that the fuel was flowing freely. Hopefully this resolves the issue. I will check back in once I get the fuel line hooked back up between the pump and the carb. Thanks for the help. |
11-05-2015, 04:58 PM | #5 |
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Join Date: Sep 2014
Location: Toms River, NJ
Posts: 437
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Re: Possible fuel pump issue
Ok I got the fuel line hooked up all the way and had nothing. Then I removed the line going into my fuel pressure regulator and hooked the mightyvac up again. Then I removed it, bumped the motor and I had fuel! I'm all set now.
Only issue I need to fix is that I can't get it started. Obviously getting fuel and I have brand new spark plugs. I try starting it and get nothing, then a GIGANTIC backfire through the exhaust. I think it's an issue with my distributor. I'm going to remove it and put it back in. I thought i put it in the right way the first time, but maybe I didn't... |
11-05-2015, 07:59 PM | #6 |
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Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
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Re: Possible fuel pump issue
Yeah, it's always a good idea to check your distributor and timing. I once saw a muffler blow up because of bad timing.
If you're familiar with checking for TDC disregard below... Insure the #1 piston is at TDC on the compression cycle. You can feel that with your thumb in the hole method or if you have the valve covers off, both intake and exhaust valve all the way up. Slowly rotate the engine until piston is at top of cylinder. Some use a piston stop for this. I use a thin dowel to feel the piston going up. Also, it's easier to rotate engine with all the spark plugs removed. The h-balancer mark should line up with TDC then you just have to make sure the rotor lines up with the #1 spark plug connector on distributor cap.
__________________
68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive... |
11-06-2015, 06:00 PM | #7 |
Registered User
Join Date: Sep 2014
Location: Toms River, NJ
Posts: 437
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Re: Possible fuel pump issue
Well I got it started today but couldnt check anything. Apparently I had it in gear and hooked up my shift rod with the trans in 1 instead of park. The diagram was confusing, but I blame myself for not doing other checks. The parking brake was always on and I never double checked to make sure it was in park so it's really just my fault.
Anyway, I crashed into my fence and banged up my radiator support and one of my fenders got a little banged up. I'm pretty pissed but it could have been way way worse. I didn't crash into my house, didn't crack the radiator or anything inside the engine bay. Now I need to replace the rad support and find a decent fender. Worst part is, my stuff was in great shape... |
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