Stranded… could use some ideas.

[7900_Blazer]

Drove from Dallas to Raton NM (615 miles) with no issues.

Turned towards Raton and the engine ‘stumbled’… then ran fine.

Then it started stumbling with every hill… ran fine on flat ground… then outside of Pueblo CO it died.

It only seems to stumble ‘under load’…

Temp never over 205 or so, good oil pressure (cruise oil pressure is right at 45 psi).

On the side of the road, I had disconnected the fuel line into the carb and had to crank it over a number of times to get fuel to pump out. I waited and in about 15 minutes it cranked and I drove it about 2 miles to an autozone where I changed the fuel pump. Below is a video of the fuel filter as after the new fuel pump… any thoughts much appreciated.

it doesn’t seem to bubble at all when it’s not at running temp of 205 or 210.

After it sits, it seems to run fine for awhile then starts stumbling again.

https://youtube.com/shorts/mSeRRcz8Zdk?feature=share

 

[Rusty Nail]

Looks like it's boiling!

What is the status of catalytic converter if any?
What happens if you remove the gas cap?

 

[7900_Blazer]

Looks like it's boiling!

What is the status of catalytic converter if any?
What happens if you remove the gas cap?

No Cat… no change when removing the gas cap

 

[yevgenievich]

Gas tank maybe has trash that gets the pickup restricted?

 

[Paladin]

A few years ago I had the exact same problem as you described. Engine ran fine until the slightest rise in grade then would begin to stumble and cut out. I would stop and let it cool a bit and would run fine for awhile then start doing it again. Was able to limp into the nearest town and changed fuel pump. Completely fixed the problem. Has run like a rape ape ever since. When I changed fuel pump I installed one with a return line. The one which was giving me the problem had no return line. Just food for thought. Good luck!!!

 

[Termite_Delight]

I was going to ask if you had a return line for your pump, you beat me to it @Paladin

 

[Rusty Nail]

There must be a leak in the line allowing air to enter..reckon id get to cuttin the ends off and resealing all them fancy hose clamp connections.
There aren't a lot of options..if it's not boiling, it's pumping air.
Revisit the clamps and look for a split hose.

 

[78C10BigTen]

Yea that does look like a boil to me too. But if its not pumpin air wouldnt that filter be full and boiling? As a temp fix id pull the feed line at the pump, blow air back through it to the tank, maybe its got crap blockin it up.

 

[7900_Blazer]

Could it be the line inside the tank? I ask because it seemed to get worse as I burned more gas… Now that it has about a 1/4 of a tank, it won’t run at all.

 

[yevgenievich]

Could it be the line inside the tank? I ask because it seemed to get worse as I burned more gas… Now that it has about a 1/4 of a tank, it won’t run at all.

Easier way to check if it getting trash in pickup is to disconnect hose behind the cab and blow back the line. If it gets better, then there is trash in the gas tank

 

[7900_Blazer]

A few years ago I had the exact same problem as you described. Engine ran fine until the slightest rise in grade then would begin to stumble and cut out. I would stop and let it cool a bit and would run fine for awhile then start doing it again. Was able to limp into the nearest town and changed fuel pump. Completely fixed the problem. Has run like a rape ape ever since. When I changed fuel pump I installed one with a return line. The one which was giving me the problem had no return line. Just food for thought. Good luck!!!

I was hoping for the same solution… changed the fuel pump in the part store parking lot… unfortunately, no change :-(

 

[bedwards]

No offense, but have you topped the tank off? The tanks don't have baffles and mine will act like its running out of gas going up a steep hill on less than a quarter tank. I would not trust the gas gauge either. Do you have dual tanks, is it switching tanks correctly and doing this on both tanks? My tank valve went bad and would not fully switch tanks.

 

[WamboJambo]

So, I have no real basis for this but just gonna throw it out there in case it helps - presumably it's a hot day and you've been driving it a while, is it possible when you stopped at the parts store and swapped the fuel pump your engine got heat soaked? Mine used to do that (old carb, has since been fixed) when I'd stop for gas and I'd have to floor it while cranking until it started. Just a random thought in case it helps you get un-stuck, but I'm a noob here

 

[Rusty Nail]

If the truck has sat any measurable time with ETHANOL in the gas tank, I believe it is VERY likely the pickup hose has failed - inside the tank. Which leads to the pumping of the air.

All you gotta do is drop the tank and change the two dollars worth of bulk rubber fuel line. Easy Peasy!

 

[7900_Blazer]

No offense, but have you topped the tank off? The tanks don't have baffles and mine will act like its running out of gas going up a steep hill on less than a quarter tank. I would not trust the gas gauge either. Do you have dual tanks, is it switching tanks correctly and doing this on both tanks? My tank valve went bad and would not fully switch tanks.

No offense at all. It started ‘stumbling’ with about 2/3rs of the tank full… but did seem to get worse as the level dropped.