Not Getting fuel

[84k20Northern]

Got a 84 K20 4X4 for free from a family freind the other day, Its got a carbed 350 and I'm planning on restoring it. It needs a new cab and box, It was used as a plow truck up here in canada for a while so the body is pretty bad. Its got dual fuel tanks which were replaced sometime before it got parked a number of years ago. It had been sitting for at least 5 or 10 years i'd imagine. I cranked it over and it wouldnt start so I primed the carb with gas about 10 times but it just burns through the prime and dies without pulling any gas from the Tanks. One tank is half full with Old gas but its not even pumping it so I don't think its old gas. I know my way around trucks and know to check filters and hoses and things like that, But is there anything in these trucks fuel systems that were known to fail?

I had it running for a good minute and a half on starting fluid but it was really rough running and still didnt pick up fuel after running half ass for a good minute and a half.

I will be pulling the box and cab off eventually and replacing all the lines and filters but need to get it running first to bring it up to the garage.

Thanks

 

[chengny]

Pull the fuel inlet to the carb, attach a hose, point it somewhere safe and crank the engine. If gas gushes out (1 pint in 15 seconds is the spec rate), the fuel pump suction lines, fuel pump and fuel pump discharge lines are okay. The carb float is probably stuck closed.


If you get nothing out of the test hose, pull off the pump suction side hose. Blow air into the tank or suck on the open end of the hose. If you get gas in your mouth or good flow with the tank (slightly) pressurized with air, the problem is with the fuel pump.

If you can get no flow from the tanks to the inlet side of the pump the tanks/switching valve/suction lines have almost certainly become plugged with broken down gasoline.

Read the first page of this thread for a similar issue:

http://www.gmsquarebody.com/forum/showthread.php?t=6628&highlight=varnish


Broken down gasoline looks like tar and smells like varnish. If that is the case, you have some serious cleaning and flushing to do.

 

[HotRodPC]

Yeah, if it's sat for 5-10 years, I'd imagine those tanks need to be dropped and cleaned. I know it's hard to find a real radiator shop these days but if you can find one, take the tanks to them and they can boil them out for about $20 a tank and make them good as new again. Hopefully you didn't suck a bunch of junk up into the fuel lines.

For purposes of seeing if you can get the truck to fire up, get a piece of about 6 ft fuel hose and clamp it on the suction side of the fuel pump and drop the hose into a gas can.

 

[marks86]

also that nasty gas was sitting in the carb for all those year, I bet the carb is in need of a rebuild

 

[84k20Northern]

Thanks, I will definately try plugging the pump into a gas can tonight and will let you guys know.

Heres a pic of my truck