Engine not getting fuel

[aruss99]

Hi all, in my past posts I've had many issues with the engine in my truck due to me being 15 and not having had much experience with troubleshooting motors. Most recently I took on the task of rebuilding my 350 which didn't go so well. The motor ended up throwing a rod and destroying the whole engine. Luckily I was able to find another 350 that supposedly ran well before sitting for 10 years. (I checked to make sure the internals of the motor looked decent)

Having gotten the motor into the truck I've had some issues getting the truck to start. I've been able to overcome many of those problems with just a little research and patience. The problem I am stuck on now is the fuel delivery. The fuel pump will pump fuel for a little bit and then stop pumping all together. I have tried putting on a different fuel pump to make sure the fuel pump wasn't the issue. I have also tried switching out the fuel pump push-rod to make sure that wasn't the issue either. This is where I am stuck. I know that there is a bolt hole on the front of the motor that goes into the same passage way as the push-rod and I made sure nothing was in there to keep the push-rod from moving freely. It appears to me that the push-rod is moving as it should which is why I don't know what the issue is.

Any and all help would be much appreciated because I don't know if pulling the cam out to see if the lobe is ground down is necessary or if there is some other potential issue that I'm unaware of. Thanks for the help in advance.

[firedemon]

could be a pluged filter , line, or tank

[71CHEVYSHORTBED402]

I don't have much experience, but any chance you have a flat cam?


http://67-72chevytrucks.com/vboard/s...d.php?t=464335

http://www.secondchancegarage.com/public/535.cfm

[aruss99]

Originally Posted by 71CHEVYSHORTBED402

I don't have much experience, but any chance you have a flat cam?


http://67-72chevytrucks.com/vboard/s...d.php?t=464335

http://www.secondchancegarage.com/public/535.cfm

That is entirely possible, the only reason I am unsure is because sometimes the fuel is being pumped and other times nothing comes out.

[71CHEVYSHORTBED402]

That link I gave you for this sight is typical. Seems most times someone has a problem, they don't follow up to explain how it was resolved.

[aruss99]

Originally Posted by 71CHEVYSHORTBED402

That link I gave you for this sight is typical. Seems most times someone has a problem, they don't follow up to explain how it was resolved.

Okay, Ill take a look at it and let you know what I find. Thanks for giving me some direction

[71CHEVYSHORTBED402]

Originally Posted by aruss99

That is entirely possible, the only reason I am unsure is because sometimes the fuel is being pumped and other times nothing comes out.

If that pump is good, and the line to the carb is good, I'd start by replacing all rubber hoses from the tank, and blow out the steels lines too. If that fails, check/replace the sender. If that fails, the only thing left seems to be a new top end.

Someone else should chime in. I'm competent, but little experience.

[aruss99]

Originally Posted by 71CHEVYSHORTBED402

If that pump is good, and the line to the carb is good, I'd start by replacing all rubber hoses from the tank, and blow out the lines too. If that fails, check/replace the sender. If that fails, the only thing left seems to be a new top end.

Okay, I have blown air through all the lines thinking that would show whether or not any lines were clogged but will physically check the sender unit at the tank as soon as I can, again thanks for the help.

[71CHEVYSHORTBED402]

Isn't there a breather hose for the fuel? I believe stock the hose fastens to an emmissions canister of some sort. With the canister gone (as most are), you put some kind of filter on the end of that hose. Any chance that's plugged up, like maybe...........a bolt?

[aruss99]

Originally Posted by 71CHEVYSHORTBED402

Isn't there a breather hose for the fuel? I believe stock the hose fastens to an emmissions canister of some sort. With the canister gone (as most are), you put some kind of filter on the end of that hose. Any chance that's plugged up, like maybe...........a bolt?

I am fairly sure my truck doesn't have a breather hose because it likes to puke gas as soon as it gets hot outside

[71CHEVYSHORTBED402]

Originally Posted by aruss99

I am fairly sure my truck doesn't have a breather hose because it likes to puke gas as soon as it gets hot outside

Ha!

[Clavo106]

DID U PRIME YOUR FUEL PUMP? its mechanical if u dont have fuel coming out of the fuel line to the fuel pump. u dont have prime.. there's a few way. look on youtube. and if u do then to check your fuel pump disconnect the line going to the carb connect a long hose to the line and runn it the a fuel container. then crank the engine over. there should be lots of fuel gushing in to the container. PLEASE WORK SAFE AND BE SAFE..

[Clavo106]

https://youtu.be/TEkFNaBhiss

[aruss99]

Originally Posted by Clavo106

https://youtu.be/TEkFNaBhiss

Thank you. I will check all of the suggestions tomorrow morning

[71CHEVYSHORTBED402]

Thanks to you I've decided to put my charcoal canister back on. On the assumption I can get it open.

[aruss99]

Hi all, I'd like to give an update to everyone as some things has changed.

Today while working on my truck I ran into issues with the starter and upon doing research I found that I have the wrong flywheel on my truck which needs to be changed out. Unfortunately with school starting for me again soon I am not sure how long it is going to be until I can have the parts I need and the time to install them. Once I have a working starter and flywheel I will be able to work on my fuel system.

Thanks again for all the assistance and help with trying to identify the problem.

[cdowns]

are u sure that u have enough fuel in the tank for fuel pump to move it

[GMCGrim]

I had some of the same problems and I held my hand over the gas tank filler tube and used my compressor to blow air into the tank which filled the lines with gas and then the engine would start and stay running.

[aruss99]

The issue when I was able to crank the motor was even when I had a line that I knew was unobstructed run to a small gas can by the motor, it pumped fuel out a couple times then didn't pump at all anymore. Which leaves me mistified to what the issue is

[cv65]

is your gas cap vented?

[68gmsee]

Originally Posted by aruss99

The issue when I was able to crank the motor was even when I had a line that I knew was unobstructed run to a small gas can by the motor, it pumped fuel out a couple times then didn't pump at all anymore. Which leaves me mistified to what the issue is

Since you're just learning to work on these trucks you picked a good site to get advice. One thing that would help on future problems you may have is to post the year of the vehicle, engine you are using. May want to also post the carb it has and whether it's points or HEI. This will help in diagnosing problems.

One more thing that will help you. Since you are now having a totally new problem, it may be better to start a new thread rather than include it in the old thread.

Re. the fuel issue I'll post what I encountered with my truck below.

[68gmsee]

Re. weak pump. I had a similar issue with my 69 truck. It would run okay for a while and then die out. Pump did the same thing yours is doing. Pump a little gas into a jar and then it trickled down. I replaced the pump and found the old one had a small crack in the diaphragm.

Few years later I had a similar symptom on my 68 and figured I would be smart and replace the pump right off. Wrong! Turned out to be a restricted fuel line from the tank to the fuel pump. Made a new one and that solved that problem.

Other fuel problems I've had were restricted fuel filter sock inside the fuel tank and unvented cap in fuel tank.

Below is a pic of a vented cap so you can tell the difference. You can gently insert a thin object and push on the inside piece. It's spring loaded and should move up and down slightly.

[aruss99]

Originally Posted by 68gmsee

Re. weak pump. I had a similar issue with my 69 truck. It would run okay for a while and then die out. Pump did the same thing yours is doing. Pump a little gas into a jar and then it trickled down. I replaced the pump and found the old one had a small crack in the diaphragm.

Few years later I had a similar symptom on my 68 and figured I would be smart and replace the pump right off. Wrong! Turned out to be a restricted fuel line from the tank to the fuel pump. Made a new one and that solved that problem.

Other fuel problems I've had were restricted fuel filter sock inside the fuel tank and unvented cap in fuel tank.

Below is a pic of a vented cap so you can tell the difference. You can gently insert a thin object and push on the inside piece. It's spring loaded and should move up and down slightly.

Thanks for the help. I was able to see that my fuel cap does not have a vent on it.