Runs out of fuel…

Octane

Full Access Member
Joined
Dec 31, 2019
Posts
1,032
Reaction score
1,544
Location
Atlanta
First Name
Eddie
Truck Year
1977
Truck Model
K10
Engine Size
350
My experience has been customers scream bloody murder if they have to pay for things that weren't needed. Most guys on here would and most would say find a different mechanic,sounds like he doesn't know what he's doing. On your own truck as Hobbie great change all the things you want,I still don't agree with it. Seriously many O.E. parts if they test good are better quality than the aftermarket replacement parts. Example an original TBI fuel pump would go for years,it dies,you put in an aftermarket pump from advance,O'Reilly, any discount parts store.Now you're changing them every 2 years or less. When I worked at Pat's shop we wouldn't install parts store pumps on FI cars.
And the guys that beat book,spend a lot of money on tools,and they diagnose.They diagnose quickly and fix the car right the first time and change only what's necessary. Any unnecessary steps cost me money.

I'm not trying to start a war,some guys like fat girls,some guys like skinny girls. It's your life,your truck and whatever makes you feel best is what's important.
I agree that aftermarket parts can be shabby.But on an old hobby truck the oem parts are long used up Everything you buy is that aftermarket crap.I agree with diagnostics of parts.I have and know of many antique/ classic vehicles that are not used much.As such,I find some parts just degrade from non use,and are at times better to replace more of a particular systems parts,than say,just the carb.It does build some reliability back into the vehicle.As a daily driver, I diagnose and replace only the absolutely required parts. Im not suggesting that a shop going for profit should ever do more than the necessary repairs.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
1,264
Reaction score
1,025
Location
kansas
First Name
Richard
Truck Year
1975
Truck Model
c20
Engine Size
350
I always diagnose before replacing if I'm chasing a problem.I might change more as preventive medicine. As example shift solenoids I will test them to verify I've found a bad one,then replace them all. But I know I found the problem before I change anything.EFI fuel pumps I'll verify the pumps bad,but replace the harness and fuel filter as preventive maintenance.But again I knew I found and fixed the problem. So replacing more than necessary, I can agree with.Changimg parts before I know what's wrong I just can't do,I have to be sure the problem is solved. Hey what am I doing here I should be out looking for a fat and a skinny girl.
 
Last edited:

Rusty Nail

Victim of Culture
Joined
Jan 29, 2015
Posts
7,774
Reaction score
6,434
Location
Your mom's house
First Name
Rusty
Truck Year
1977,1988
Truck Model
C20, K5
Engine Size
350, 350
Fuel filter installed backwards OR missing spring OR both.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
1,264
Reaction score
1,025
Location
kansas
First Name
Richard
Truck Year
1975
Truck Model
c20
Engine Size
350
I'm sorry I didn't start at post 1. I got involved right after someone asked how to test a fuel pump and things went sideways from there. I suspect a really low float level so there isn't enough fuel in the bowl,the little fuel that is there is evaporating or seeping through the well plugs leaving you dry after sitting,sitting, not enough fuel in the bowl to drive around the block.Still test fuel pump pressure and volume first.If they are good then the problem is after the pump. Ta Da fuel filter or carburetor, did you see the wonders of diagnosing. And yes a mechanical pump even a new one can pump below volume especially if the pump pushrod is the wrong length or the pump lobe is going flat.
 
Last edited:

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
46,316
Reaction score
7,049
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB / 86 K5
Truck Model
Silverado / Silverado
Engine Size
454 - Turbo 400 - 3.73 350 - 700R4 - 4.10
Ahhhhhhh..... another thread involving a vehicle not wanting to stay running with the Wonderful, Glorious, Magnifcent Q-Jet...! Isn't that a complete surprise, NOT!!! Now shall come all the responses of people who haven't learned from history!!!! LOL:popcorn:
The biggest problem with a Qjet is they're rarely rebuilt right to where the factory problems are ever rectififed. Seal the well plugs, and bush the throttle shafts, then you'd have a good carb. You can't "just put a kit in it" on a QJet, unless it's been rebuilt RIGHT previously.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
46,316
Reaction score
7,049
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB / 86 K5
Truck Model
Silverado / Silverado
Engine Size
454 - Turbo 400 - 3.73 350 - 700R4 - 4.10
I'll go with 2 problems. Leaking well plugs in the carb, AND bad check valve in the fuel pump. I wouldn't worry near as much about the check valve in the fuel pump. So long as you've got fuel left in the fuel bowl, it should start up no problem and before it ran out of fuel, the fuel pump would have caught up and you'd likely not notice the check valve is bad. You're just having a combo of issues making it appear extreme. My truck is the same way and I don't worry about it, cuz I know what it is and it'll never leave me stranded, and once I'm driving it, no matter where I go, it'll start right up. I only have the issue if it sits for a couple days, so the problem is only at home.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
1,264
Reaction score
1,025
Location
kansas
First Name
Richard
Truck Year
1975
Truck Model
c20
Engine Size
350
I'll go with 2 problems. Leaking well plugs in the carb, AND bad check valve in the fuel pump. I wouldn't worry near as much about the check valve in the fuel pump. So long as you've got fuel left in the fuel bowl, it should start up no problem and before it ran out of fuel, the fuel pump would have caught up and you'd likely not notice the check valve is bad. You're just having a combo of issues making it appear extreme. My truck is the same way and I don't worry about it, cuz I know what it is and it'll never leave me stranded, and once I'm driving it, no matter where I go, it'll start right up. I only have the issue if it sits for a couple days, so the problem is only at home.
He said won't drive around the block without running out of gas,has replaced the pump,and has just rebuilt the qjet. That's why I suspect a really low float level.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
1,264
Reaction score
1,025
Location
kansas
First Name
Richard
Truck Year
1975
Truck Model
c20
Engine Size
350
Ahhhhhhh..... another thread involving a vehicle not wanting to stay running with the Wonderful, Glorious, Magnifcent Q-Jet...! Isn't that a complete surprise, NOT!!! Now shall come all the responses of people who haven't learned from history!!!! LOL:popcorn:
Sorry it took a little while to research, GM built millions of trucks with qjets that ran real well for a long time. Thousands of truck owners rebuilt,had rebuilt, or purchased a rebuilt qjet, and ran real well for a long time again. Now 793 truck owners chose an Edelbrock over a rebuilt qjet and 679 of them ended up on here asking how to make it run right. Your move.
 
Last edited:

Octane

Full Access Member
Joined
Dec 31, 2019
Posts
1,032
Reaction score
1,544
Location
Atlanta
First Name
Eddie
Truck Year
1977
Truck Model
K10
Engine Size
350
I always diagnose before replacing if I'm chasing a problem.I might change more as preventive medicine. As example shift solenoids I will test them to verify I've found a bad one,then replace them all. But I know I found the problem before I change anything.EFI fuel pumps I'll verify the pumps bad,but replace the harness and fuel filter as preventive maintenance.But again I knew I found and fixed the problem. So replacing more than necessary, I can agree with.Changimg parts before I know what's wrong I just can't do,I have to be sure the problem is solved. Hey what am I doing here I should be out looking for a fat and a skinny girl.
You know what they say about a fat chick and a bicycle!
 

RecklessWOT

Full Access Member
Joined
Feb 20, 2015
Posts
1,168
Reaction score
1,807
Location
New Hampshire
First Name
Kevin
Truck Year
1987
Truck Model
V10 Suburban Silverado
Engine Size
350 TBI
How exactly would you test whether the “fuel pump is good?”

It starts, runs, & revs, and it will idle until i turn it off.

it seems to me, that’s fairly conclusive evidence the fuel pump is working.

Are you suggesting that it’s not pumping at full capacity?

It is completely possible. I have an old Jeep CJ that I use as a yard truck/ glorified plow tractor, the thing is in a deep state of neglect (has been that way since I picked it up for free from the original owner's widow and I'm assuming it has been that way long before I owned it). It had the exact same symptoms you are explaining. I would have to spray it with a ton of starting fluid or dump fuel straight down its throat to get it to start. After that it would restart just fine. It would idle all day and would move around fine at light throttle. When giving it a lot of gas it would sputter, and after driving it more than a short distance it would habitually stall out on me as if it were out of gas. I always assumed the carb was full of crap in addition to having a zillion vacuum leaks or something along those lines. Well one time after hammering on it for a few minutes it finally dies on me (while turning around in the street in a big snow storm of course) and I can't get it started to save my life. I could fill the bowl with a gas can and it would just run until that ran out. I took the fuel filter off figuring it was clogged, and for the hell of it while it was off I cranked it over to see if anything at all came out. Turns out the fuel pump was on its way out for a while and it finally died, the thing was completely shot. I put a new one on and all the other symptoms went away too, runs like a top now.

Even though your pump is new, it is possible it was bad out of the box if not manufactured properly. Some those parts store units are just junk, if it's new enough I would just bring it back and say it is no good and try another new one. If that fixes it, there you go. If not, well at least you can confidently cross that one off the list.
 

BJedi76

Full Access Member
Joined
Nov 7, 2019
Posts
146
Reaction score
16
Location
Soldotna, Alaska
First Name
B.J.
Truck Year
1986
Truck Model
GMC Sierra Classic 1500 4x4 SWB
Engine Size
305”
It’s the third new fuel pump.

One replaced by me, the two others replaced by Midas.
 
Last edited:

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
1,264
Reaction score
1,025
Location
kansas
First Name
Richard
Truck Year
1975
Truck Model
c20
Engine Size
350
It’s the third new fuel pump.
Okay now check fuel pump pressure and volume. This is not a stupid request! There is a push rod that operates the pump, wrong length push rod = incorrect fuel pump operation. There is a lobe that works the push rod that works the fuel pump.Worn out lobe= incorrect fuel pump operation. This is why I diagnose, not just part swap. Diagnoses saves time, money and frustration. Now as I said before you need to test for proper pressure and volume. If that passes the problem is past the pump. Meaning its at the carburetor.
 
Last edited:

BJedi76

Full Access Member
Joined
Nov 7, 2019
Posts
146
Reaction score
16
Location
Soldotna, Alaska
First Name
B.J.
Truck Year
1986
Truck Model
GMC Sierra Classic 1500 4x4 SWB
Engine Size
305”
I took the carburetor off.

I reset the float, tap set the float ball, and adjusted the power piston down just a bit.
 
Last edited:

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
1,264
Reaction score
1,025
Location
kansas
First Name
Richard
Truck Year
1975
Truck Model
c20
Engine Size
350
So is it fixed? Too low float level?
 

Latest posts

Forum statistics

Threads
33,654
Posts
697,072
Members
21,204
Latest member
Philip Reeves
Top