Trollhole troubles?

[alaska60]

I started having bucking and sputtering issues with my 40. It is desmogged and trollholed. When I step on the gas pedal it falls on its face and bucks and sputters. I took the air horn off and cleaned the jets, accelerator pump assembly, blew out all ports and reassembled. It ran great after doing so.......until about 30 miles later it started acting up again...same issue!

and yes, I replaced fuel pump, fuel filter and replace all the lines with new. I even flushed the tank too. It ran great for the last 15,000 miles since I put the trollhole carb on. Then all of a sudden...WHAM! Took the carb apart and it fixed it for 30 miles...Then, WHAM! again!

any thoughts?

 

[SouthBostonFJ40]

Did you ask Marshall?

Sent from my iPad using IH8MUD

 

[alaska60]

havent talk to him yet..

 

[camcruiser13]

Sounds like a fuel
Issue

 

[alaska60]

Sounds like a fuel
Issue

I know its a fuel issue....

but what and where is where I am stumped... It ran better and farther after the cleaning of the jets and AP. Maybe another cleaning?

 

[Slowerthanu]

Is this the first warm weather since the rebuild? Could it be vapor locking on you?

You may have stirred up more harm then good when you flushed the tank. Maybe drain the fuel and inspect for scale or anything?

You used fuel rated hose correct (I know, stupid question but you would be surprised)?

It's a dirt or vapor lock issue guaranteed. You cleaned, ran it for a while and boom, problems. Let it cool completely and drive it again.

 

[alaska60]

Is this the first warm weather since the rebuild? Could it be vapor locking on you?

You may have stirred up more harm then good when you flushed the tank. Maybe drain the fuel and inspect for scale or anything?

You used fuel rated hose correct (I know, stupid question but you would be surprised)?

It's a dirt or vapor lock issue guaranteed. You cleaned, ran it for a while and boom, problems. Let it cool completely and drive it again.

I am in Utah...Its been hot the last two days too. The problem was there prior to the flushing of the tank. I did use fuel hose too. I flushed to see if something was in the pick up or lines. It is hot on the carb to the touch. I just went out and took the airhorn off and re cleaned everything again. It ran great for about 15 minutes, but the first hill I got too, it fell on its face agin....so frustrating.
Any ideas for solving the potential vapor lock?
Thanks for the vapor lock idea....Im a rookie when it comes to hot weather. My first Utah summer!!!!! Its hot!

 

[alaska60]

I have run this set up this rig in hot weather before with no issues....im leaning more to the dirt factor.

 

[oregonfj]

My 40 was acting just like that and it turned out to be a loose fitting on the fuel pressure regulator. Any chance for the fuel line to start sucking air somewhere and it will run like crap.

 

[alaska60]

My 40 was acting just like that and it turned out to be a loose fitting on the fuel pressure regulator. Any chance for the fuel line to start sucking air somewhere and it will run like crap.

a fitting on the fuel pressure regulator?
On the pump?

 

[edwjmcgrath]

Things to check next time this happens.
How is the fuel level in the bowl? If you pump the accelerator, do you get a good solid squirt?
A bad accelerator pump can easily cause the symptoms you are seeing.
Finally, I'm a big fan of clear fuel filters when you are trying to diagnose fuel flow issues. A new filter can clog up very quickly.

On the vapor lock issue, does your trollhole have a return line? That helps keep the fuel cooler by keeping it flowing all the time. Do you see bubbling of fuel in the bowl when this happens?

 

[Southeast Overland]

Have you looked inside your tank for rust? Sounds like a rusty tank to me. Especially when your truck runs well after flushing the fuel system.

 

[oregonfj]

a fitting on the fuel pressure regulator?
On the pump?

At the time I had a adjustable regulator between the mechanical pump and carb. I went through my carb three times and still the same problem. I checked fuel pump output by pumping into a jar, it was good. I blew air back through the line to make sure the pickup wasnt clogged. Still it cut out under any load. Finally I notice a slight wet spot under the regulator and found the fuel line fitting was loose where it threaded into the regulator. Solved my problem instantly.

 

[alaska60]

Things to check next time this happens.
How is the fuel level in the bowl? half way up the glass If you pump the accelerator, do you get a good solid squirt?Solid stream
A bad accelerator pump can easily cause the symptoms you are seeing.could it go bad after 9 months on a new carb?
Finally, I'm a big fan of clear fuel filters when you are trying to diagnose fuel flow issues. A new filter can clog up very quickly. Its a clear one like I always use

On the vapor lock issue, does your trollhole have a return line? No it does not..That helps keep the fuel cooler by keeping it flowing all the time. Do you see bubbling of fuel in the bowl when this happens?

No bubbling!

Have you looked inside your tank for rust? Sounds like a rusty tank to me. Especially when your truck runs well after flushing the fuel system.

It ran great for almost a year like this. i flushed out the tank after draining it...some small deposits came out but nothing extreme

 

[alaska60]

At the time I had a adjustable regulator between the mechanical pump and carb. I went through my carb three times and still the same problem. I checked fuel pump output by pumping into a jar, it was good. I blew air back through the line to make sure the pickup wasnt clogged. Still it cut out under any load. Finally I notice a slight wet spot under the regulator and found the fuel line fitting was loose where it threaded into the regulator. Solved my problem instantly.

I dont have a regulator...
I'm going to see what type of pressure I have off the pump. I did replace the pump with a pump off of a 40 in the yard that runs perfect....so I can only assume it will be running perfect for me in this 40. But i will check and report back in a few minutes.

 

[oregonfj]

I dont have a regulator...
I'm going to see what type of pressure I have off the pump. I did replace the pump with a pump off of a 40 in the yard that runs perfect....so I can only assume it will be running perfect for me in this 40. But i will check and report back in a few minutes.

I would check all the connections in your fuel line, especially on the suction side of the pump. Also run it with the gas cap off. It might not be venting correctly.

 

[Trollhole]

Two things. Go out and put a paper lip on the secondary rod linkage so it's flush with secondary diaphragm housing then go drive it. When you mash the accelerator and it starts stalling turn the cruiser off and coast to the side of the road. Do this someplace safe. Get out and look at the sight glass and report the fuel level back and the location of the paper clip. Can also call me tomorrow and we can go through things. Sorry for the troubles but we will get you fixed.

 

[alaska60]

Okay....
I pulled the line off the carb and put it in a jar. I pulled the coil so it wouldnt fire. i cranked it over for 15 seconds i ended up with an initial squirt of gas and then nothing. A total of 2 tablespoons.
I then hooked the coil back up and fired it. I ended up with a cup and a half in the jar in 15 seconds....

Should I be getting more fuel then this?

I'll check all the connections too like Oregonfj recommended. Its just sooo weird it runs great for a year and WHAM...5 knuckles to the face..WTF?

 

[alaska60]

Two things. Go out and put a paper lip on the secondary rod linkage so it's flush with secondary diaphragm housing then go drive it. When you mash the accelerator and it starts stalling turn the cruiser off and coast to the side of the road. Do this someplace safe. Get out and look at the sight glass and report the fuel level back and the location of the paper clip. Can also call me tomorrow and we can go through things. Sorry for the troubles but we will get you fixed.

Yeahhh....Marshall.
Ill go this right now...be back (hopefully) in 10 or 15 minutes.

 

[alaska60]

Hey marshall,
Im having trouble figuring out where this paper clip goes and how to attach it. Is there a view of this procedure anywhere. sorry for the dumbass question but Ive never diagnosed anything with a paper clip before.
Thanks bro.