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Discussion Starter · #1 ·
I've been driving for the last 15 years on elect fuel pumps. Ok.... Car sits,,, turn on the pumps,,,pump gas, and engine fires. I'm recently on my second car in last two months with mech pump(s). They both seem to starve for fuel if they sit for more than 2 days. Engine has to crank and I have to pump the gas like crazy in order for the engine to start. Do the mech pumps suck fuel out of carb bowl when sitting? These are both Edelbrock Carter AFB style. I've tried an Omega loop...no luck. Does anyone sell a fuel filter with a check valve??. This is driving me nuts..........
 

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Discussion Starter · #3 ·
Dave,, for the most part, most of the line is 3/8" steel. I took out the temporary Omega loop hose. Still perplexed......
 

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I had a couple of Q-jets that acted like that.Some one once mentioned that there were plugs in the bottom of the fuel bowl (float bowl) that could allow the fuel to leak out causing the hard starting.
Dave
 

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The Eddy/AFB didn't have the same problem with the casting plugs leaking like the Q Jets. (Epoxy fixes that problem right up on a Q Jet though ... ;) )

Even the smallest leak/crack in a fuel line can cause the fuel to drain back out of the carb. Mechanical fuel pumps can also cause this if they are tired.

Stock Q Jets have a tiny check valve in the fuel filter to help prevent bowl siphoning. I'm not sure if the Eddy/AFB has the same type of setup.
 

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Discussion Starter · #8 ·
Thanks for your response Don, I appreciate it. I couldn't find a leak. I also don't know how tired the pump might be either. I do know it has 2,600 miles on it. Seems like a decent fix might be a fuel filter with a built in check valve, but I can't seem to find one. Summit, Jegs, etc. Or a check valve only.....??
 

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Discussion Starter · #10 ·
A fellow at work mentioned Summit had an inline fuel check valve.... for racing purposes I suppose. A little pricey at @ $85 but if it works, I'll budge....
The new question is where would be the best place for it??? I would think just before the pump????... Any thoughts?

I do want to thank everyone that has responded. I appreciate it......Rich
 

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Check Valve

Just my thought I like to elimiate as much of the gas line as possable
and put it as close to the carb as possable.
 

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For 85 bucks it should come with instuctions on where to place it, I would think as close to the carb as possible also. Check your tank venting and have the rite gas cap. Manual pumps are cheap buy a new one first. I like the '60z style Corvette pumps as you can unscrew the lower end and rotate fitting where needed best. JMO, Lon
 

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after two days you should still have enough fuel in the float bowls to pump the gas a few times and it should fire right up. this usually allows enough time for gas to start pumping. you may want to inspect needle and seat and make sure your not dripping gas from the carb .
 

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Discussion Starter · #14 ·
The carbs are dual quad setup. Edelbrock (Carter afb style). These are new, so I suppose any float/needle seat issues would probably be inconclusive. I did however e-mail Edelbrock, and their response was fuel percolation due to heat after the engine is shut off. Their fix would be to place their 3/8th " insulating gasket under each carb. I dunno...... Car runs at @170-180 degrees normally. But I guess it's worth a try. The fuel pump only has 2300 miles on it, so maybe I'll see what happens with the gaskets first.....Thanks all ......:)
 

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In all my years working on Chevy's I have never seen one percolate, Ford yes, Chevy no. That does not mean that it can't happen in your climate though. Those "insulating gaskets" are ugly especialy on duals and just a band aid that may or may not work. Don't have all the answers and don't want to harp on this to death BUT most all fuel pumps have a check valve in them so that when in pump mode it only has one way to go, to the carb. Just because you only have 2300 miles on it dosn't rule out a faulty check vavle or diaphram. I would assume that the valve also stops gas from heading back to the tank. Take a junk one apart sometime you will see what I mean. Really hard to diagnose over internet or ph. but good luck. Lon
 

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Discussion Starter · #16 ·
Hey Lon....that's what I want to hear! I don't mind spending if I think it would do some good. But your response seems to make sense.
My timing is right on, the temp is cool, and your right,,,, 2300 mi doesn't mean a thing. I think a new pump is probably in order.
And please......your not beating this to death. This is what the forums are about. I really appreciate yours and everyone else's response. If I don't have to be a parts changer (chaser), all the better. When I get off of these 10 hrs shifts, the OSU game Sat,,, and the Browns on Sunday,,,, a new pump is going in. I'll let you all know how it fares... Thanks again...Rich
 

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My post was ASSUMING you don't have a gas leak in the fuel lines, carb not leaking inside or out, tank is properly vented, etc. What baffles me, like 55delray says, why isn't the fuel in the carb bowl enough to fire it? Chev'y can be real cold blooded is your choke working like it should? if not you could be cranking 4 a long time because of it. Do you have a coil? If so do you have the resitor wire going to the "R" terminal on the starter so you get 12 Volt to the coil in start mode?
And about the perculating thing, Chevy put all V-8 dual exhaust models fuel lines on the outside of the frame for a reason. If you have a stock single exhaust car or 6 cyl. car and changed to V-8 and duals, you should also rerout the fuel lines. Lon
 
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