'85 K20 350ci died out on the road not getting fuel to carb, replaced fuel pump and now not getting fuel to pump

[klarster]

Hi folks! First post in this group so I'll try to cover all the bases in an effort to get the best outcome. Bought an '85 K20 with factory 350 and manual tranny off a college kid a couple months ago with intentions to drive while I do some work on my Jeep to get it roadworthy again, then begin restoration on the square body. Was told the carb, fuel pump and fuel sending unit were new within the last two years, approximately 2,000 miles. Sucker loves to guzzle the gasoline, which works out great because the Holley 650cfm he just put in loves to deliver it while I listen to the true duals with Thrush 2s. Ran out to a buddy's place last week to hang out and have some beers while turning wrenches on his car, then left and made it about a mile, where I turned a corner, accelerated and passed into 4th gear and the sucker sputtered a couple times and fell on its face. Wouldn't fire back up. Pulled off the fuel line from the bowl, no fuel. Pulled the fuel line off the pump, no fuel there either. Came to the conclusion (a little too hastily?) that fuel pump was cashed, so I put in a new fuel pump. Complications arose with the factory fuel line which looked beat to hell from the last time it was off so I got one from a junk yard. Got everything put together with exception of fuel line to the bowl, figuring it might take a bit to pump fuel from the tank to the carb so I elected to cheat. Got out the nurse tank and ran a line straight to the bowl. Sucker fired up with no issue but after about 8 minutes idling, no fuel ever came up to the hard line, which was just sitting open above the intake manifold. Everything I'm reading indicates I should have had fuel by that point, assuming nothing else is amiss. Which leads to the question, why the deuce don't I have fuel?? I'd just topped off about 25 miles before it died, so I know there's plenty in the tank. While the pump was off, I did have a buddy crank the engine over for me to confirm the rod is moving as it should. Do I maybe have a fuel line blockage that's causing all my problems? Is there a way to check without having to drop the tank? Any help would be so great. Thanks!

 

[AuroraGirl]

Hi folks! First post in this group so I'll try to cover all the bases in an effort to get the best outcome. Bought an '85 K20 with factory 350 and manual tranny off a college kid a couple months ago with intentions to drive while I do some work on my Jeep to get it roadworthy again, then begin restoration on the square body. Was told the carb, fuel pump and fuel sending unit were new within the last two years, approximately 2,000 miles. Sucker loves to guzzle the gasoline, which works out great because the Holley 650cfm he just put in loves to deliver it while I listen to the true duals with Thrush 2s. Ran out to a buddy's place last week to hang out and have some beers while turning wrenches on his car, then left and made it about a mile, where I turned a corner, accelerated and passed into 4th gear and the sucker sputtered a couple times and fell on its face. Wouldn't fire back up. Pulled off the fuel line from the bowl, no fuel. Pulled the fuel line off the pump, no fuel there either. Came to the conclusion (a little too hastily?) that fuel pump was cashed, so I put in a new fuel pump. Complications arose with the factory fuel line which looked beat to hell from the last time it was off so I got one from a junk yard. Got everything put together with exception of fuel line to the bowl, figuring it might take a bit to pump fuel from the tank to the carb so I elected to cheat. Got out the nurse tank and ran a line straight to the bowl. Sucker fired up with no issue but after about 8 minutes idling, no fuel ever came up to the hard line, which was just sitting open above the intake manifold. Everything I'm reading indicates I should have had fuel by that point, assuming nothing else is amiss. Which leads to the question, why the deuce don't I have fuel?? I'd just topped off about 25 miles before it died, so I know there's plenty in the tank. While the pump was off, I did have a buddy crank the engine over for me to confirm the rod is moving as it should. Do I maybe have a fuel line blockage that's causing all my problems? Is there a way to check without having to drop the tank? Any help would be so great. Thanks!

Dual tanks? one tank? YOu need to follow your fuel line back to the tank and that means inside of it. Your sock could be plugged. when my pickup on the tank plugged, the engine would only idle barely with the idle set screw at an extreme barely open. You taking a corner sounds just like that

hows your vent line to your canister and how your return line to the fuel tank(s) , is your fuel pump installed right, is the pushrod where it should be, is that bolt on the block where it should be. forget the extent of their importance, but still.

Hows your oil look? Smell gas, level high?
is your gas tank cap being left on, is your gas cap original or etc, whats the valve inside look like, did you blow air in the in beteeens of the lines when they were off?

 

[kidego31]

Pull the line off the fuel pump to the tank and blow a little air pressure in it. Have your gas cap off and listen for the air. Sounds like you have a plugged line or a plugged pick up sock

 

[klarster]

@AuroraGirl It's a single tank. For always wanting a square body since I was a teenager, I sure don't seem to have done much for research into common issues cause I'm not familiar with this pickup sock. Didn't think to check canister vent line or return line, so I'll definitely be checking on that thoroughly too. I checked and double-checked the fuel pump was in right, including the position of the pushrod. I'll have to check into the bolt you mentioned too, I'm not familiar with that either...

@kidego31 I'll absolutely give this a try. I would love if the answer to my woes were as simple as something like this, but meantime I'll stay buckled in, just in case things get hairy.

 

[AuroraGirl]

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the one sticking out

 

[klarster]

Must be a different engine or something, I haven't seen that bolt on mine. Also my fuel pump is only mounted with two bolts, not sure if that makes much difference?

 

[AuroraGirl]

Heres mine
See the top bolt in the back? That maybe is more helpful of a example

 

[klarster]

I just finally found a thread talking about the significance of that bolt. Sure wish I woulda known that before; that absolutely would have saved me a lot of frustration!

 

[AuroraGirl]

I just finally found a thread talking about the significance of that bolt. Sure wish I woulda known that before; that absolutely would have saved me a lot of frustration!

you didnt install it?

 

[Bextreme04]

I just finally found a thread talking about the significance of that bolt. Sure wish I woulda known that before; that absolutely would have saved me a lot of frustration!

Its a bear to get that pump in there without it, especially if you don't have the engine turned over to where the pump shaft is on the back of the eccentric. You said your budy cranked the engine while you felt the pushrod move?

The only thing it could be in that case is either the pump sock in the sender is plugged(see the "sock" filter on the end of the sending unit in the picture below), the fuel line is plugged, or you have a big leak in the fuel line that is letting the pump pull air instead of fuel.

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The best way to see if it is plugged is to just blow compressed air through the feed line and see if it goes through easily. Make sure you have the fuel cap off and that you have regulated the pressure way down if you do this though. I would recommend just dropping the tank and see what it looks like in there. It took me about 2 hours to pull both of my 20 gallon saddle tanks, clean them out, and put all new senders and rubber lines in both tanks when I first bought it. It had sat for about 12 years before I bought it, so I had it towed home and just replaced the entire fuel system and cleaned out the tanks.

 

[Bextreme04]

Its also worth noting that just because its a new pump, doesn't mean it is any good. I had a brand new carter pump fail on me within 500 miles on a brand new engine rebuild. I have had very good luck with the Delphi pumps from autozone. The one on my truck now is a Delphi AMF0004

 

[oldretiredafguy]

Welcome to the forum from N. Texas. You've already found the value of the vast knowledge available from the members on any subject, sometimes even pertaining to GM trucks (just kidding guys & gals). A great bunch of folks here.

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Pictures, pictures, pictures!

 

[scrap--metal]

It's gotta be a plugged up fuel filter or pick-up in the tank if fuel never made it out of the new fuel pump. The pick-up in the passenger side tank on my K10 is plugged up right now. One day it just quit, the truck simply wouldn't start anymore, so I've been using the driver's side tank ever since. I miss the dual tanks, but haven't made the time to deal with it.

My K20 was eating rust/scale from the tank and plugging the fuel filter. At least that truck would run and idle strong, it just couldn't get enough motion potion to maintain highway speed.

Good luck!

 

[fast 99]

Its also worth noting that just because its a new pump, doesn't mean it is any good. I had a brand new carter pump fail on me within 500 miles on a brand new engine rebuild. I have had very good luck with the Delphi pumps from autozone. The one on my truck now is a Delphi AMF0004

True, the shops I worked at wouldn't install off brands. They would only use Delphi or OEM. Didn't matter if it was mechanical or fuel injected electric. Almost without exception off brands would fail within a year. They didn't want an unhappy customer or warranty replacement.

 

[AuroraGirl]

True, the shops I worked at wouldn't install off brands. They would only use Delphi or OEM. Didn't matter if it was mechanical or fuel injected electric. Almost without exception off brands would fail within a year. They didn't want an unhappy customer or warranty replacement.

ive had good luck with Delphi pump in my car. But thats a 99