350 Fuel Issue

[83chevycustom]

Recently bought a 83 custom deluxe and I have to prime it every time i start it. The fuel filter is clear and after i start it the filter fills up to about half way and after i cut if off it drains back out. The fuel filter is bad i know that much because after it drains out the gas thats left is a brownish color. I was told it could be the  needle valve and also told to take the line off and prime it till full and put it back on.

[Fairlane514]

I assume factory quadrajet?

[bd]

Welcome to the site from Central California. 

If it still has the QuadraJet carburetor, the fuel well plugs at the bottom of the fuel bowl are probably leaking and draining into the manifold - carb is due for an overhaul and the well plugs will need to be sealed.  You need to address the brown fuel issue.  Either the fuel is old and varnished or moisture/condensate has accumulated in the tank(s).  Drain the tank(s), purge the lines and replace the fuel filter(s).  If the fuel is really bad, you may need to replace the fuel pump, too.

[timthescarrd]

I'm having the same issue on my 84, the longer it sits the longer you have to crank to get it to start, mine will also suck the filter almost completely empty at higher rpms than idle.

I am running a brand new Edelbrock 1406 with fuel plumbed tank>fuel pump>filter>Pressure Regulator> pressure gauge>carb  My gauge shows very low pressure (2-3 psi) sometimes not even registering at idle.

I was thinking the problem was a bad fuel pump, but haven't had time to look into it yet.

[starkey]

On my old 83 chevy C10, I had the low pressure issue in one of my tanks. When using my drivers side tank, the fuel filter would always be full of fuel, using my passengers side, the fuel filter would barely fill. It turned out that the fuel line coming from the passengers side wasn't connected all the way on the fuel tank selector valve and was sucking air a the connection.

[bd]

I'm having the same issue on my 84, the longer it sits the longer you have to crank to get it to start, mine will also suck the filter almost completely empty at higher rpms than idle.

I am running a brand new Edelbrock 1406 with fuel plumbed tank>fuel pump>filter>Pressure Regulator> pressure gauge>carb  My gauge shows very low pressure (2-3 psi) sometimes not even registering at idle.

I was thinking the problem was a bad fuel pump, but haven't had time to look into it yet.

If you use an OEM mechanical fuel pump, remember to test draw (15 - 20" Hg), pressure (5 - 7 PSI) and volume (~1 qt in 20 seconds of cranking).

Incidentally, fluctuating fuel level within a filter doesn't necessarily indicate a problem.

[Captkaos]

As stated by bd, the glass filter won't stay full when the motor is running.  The carb runs off what is in the bowl and the pump "tops" off the bowl while pumping.

If the gas it discolored I would suspect tarnish issues.  If you are having to prime it to start is this after sitting for a few hours or days?  It isn't going to be like a new injected vehicle that primes automatically and is injected, it will have to turn over a couple times before it is primed.  If this is hours, I would say it is the well plugs if a Q-jet as bd stated.

[83chevycustom]

If it sets for a couple hours i have to prime. Also I forgot to mention that when driving home it shut off a few times and had to prime it to get started back.

[83chevycustom]

Thanks for the replies guys but i think I'm gonna rebuild the carb like bd said. But the filter is so bad off that's why after the fuel drains out its brownish color. After i get it started it the fuel looks normal. But if the carb rebuild doesn't fix it ill try replacing fuel pump.

[Captkaos]

If the filter has clear gas in it and then it turns brown, you just found your problem.  It isn't the filter, it is the tank.  I would suspect that the filter in the tank is gone.  I would definitely rebuild the carb, but I would also get a glass jar and pump the fuel out into it from the truck and let it settle and see what the contents are.

[83chevycustom]

If the filter has clear gas in it and then it turns brown, you just found your problem.  It isn't the filter, it is the tank.  I would suspect that the filter in the tank is gone.  I would definitely rebuild the carb, but I would also get a glass jar and pump the fuel out into it from the truck and let it settle and see what the contents are.

Well today i changed the filter and fuel pump and now theres now gas coming to the filter. Lines are not clogged.

[bd]

Don't you just love trucks!? 
Is the filter on the suction or pressure side of the pump?  Verify that your new fuel pump has adequate draw, pressure and volume, using the following criteria...

If you use an OEM mechanical fuel pump, remember to test draw (15 - 20" Hg), pressure (5 - 7 PSI) and volume (~1 qt in 20 seconds of cranking).

If the pump has adequate suction, it's probably drawing air.  Like Starkey suggested, check for bad hoses, connections, perforated lines, fuel selector valve (if you have two tanks), etc.  Or, there could be a problem with the pick-up or standpipe in the tank, as Captkaos expressed.

Regardless, you should follow Captkaos' advice.

...get a glass jar and pump the fuel out into it from the truck and let it settle and see what the contents are.

[83chevycustom]

OK I had another post on my 83 c10's fuel issue. Now i know i might have confused everyone cause i didn't know how to explain it very well. But today i replaced the fuel pump which turned out to not be the problem. Turns out theres no fuel getting to the pump. So tomorrow I'm gonna check for holes in the line running from the tank to the pump.

[83chevycustom]

Oh and I should also state that the truck was running but still having the fuel problems "until i ran out of gas".Fuel gauge doesn't work.  After I ran out of gas it set in my driveway for about a week until i put more in it. Now fuel doesn't get to the pump. I blew compresses air through the line to make sure it wasn't clogged. I don't know what else to do. And one more thing i would. Thank you bd and captkaos for helping me on my last post.

[Fairlane514]

I think you mean"no" gas?    Did the fuel pump rod get put back in position when you changed the pump?