Engine cuts then coughs and hacks before running again

Did you hook the fuel lines up to the pump backward?
I ask, because that layout can be confusing. Especially if you have one of those pumps that also runs the windshield wiper motors.

 

Electric wipers. The 5/16 lines are connected to the 5/16 ports; likewise for the 1/4 inch lines. To be clear, the tank has both a 1/4 and 5/16 metal tube connection at the float/sender. From there corresponding sized rubber hose goes to the engine compartment where it connects to metal tube again. These then connect to the fuel pump via short rubber hose. Two sizes of tube/hose and I ensured the were consistent, not mixing the sizes. A third connection on the pump, also 5/16, connects to the filter. The output from the filter goes to the carb.

Today I'll try to ensure the pump is moving fuel into a quart jar.

Regards,
Tim

 

Just the opposite on this girl! About 3 feet of rubber hose from tank to engine, then hard lines across engine to fuel pump with short 2-3 inch rubber hoses connecting in and out of pump, to filter, then out of filter and then a hard line to the carb.

1/4" is the fuel line, 5/16 is return line. Having written that down, it doesn't make sense...

Regards,
Tim

 

I had many problems like this one and now all works well, execept when the fuel tank is too low.

1 - I found with help of the forum that the accelarator pump on the carb was full of herb dust. Afer thouroughgly cleaning it was ok.

2 - I had a spark plug broken, it was working but not always. I changed the spark plugs and it is perfect.

There are many other possibilities, you can only check one by one.

The most risky is to touch at the ignition system, because difficult to check. In fact my ignition system was good, only carburetor problem.

2 days ago I have seen that the 2 screws of the carb were not very tighten. So again action.

At first I had bad contacts in the wiring, some wire were spoiled, nude and when driving sometimes were touching the body and problem.


Yhis is just to say that you must keep hope in the Future. It will work well one day.

 

Looking at it all it appears to me it may not be connected properly, however why would the 1/4" connector on the fuel pump be the intake, and the 5/16" be the return? Or should I just replace the 1/4" hose with 5/16" and ensure they are connected to the correct places?

Time to carefully run through this all again tonight (post work).

Regards,
Tim

 

They do. And looking at it closer it appears all is connected properly.

Fuel pump:Line on left is 5/16", middle is 1/4" and the elbow right is the output 1/4" to the filter.
According to my FSM fig E-33, 5/16" is fuel inlet, 1/4" is vapor return and elbow on right is the fuel outlet.


New fuel filter. 5/16" lines on both ends. I checked, it flows "up".


Fuel lines in general. The two lines into the pump lead up and then back over the cylinder bank to the firewall. From their two rubber hoses continue across then down and aft to the fuel tank.

From the fuel filter the 5/16" hose connects to a 5/16" metal pipe that goes to the carb.


Fuel tank & sender. Tube (5/16") on left is fuel out and right one is 1/4" and vapor return.


Regards,
Tim

 

Test done and fuel flow confirmed almost immediately (about 5 seconds gave me about 5 ounces).

Where should I look next? Points?

regards,
Tim

 

I had a simular problem with my jeep. It would shut off at not any certain time, then catch back up.
Turned out to be a loose wire on the ignition switch. Fixed that and been running ever since..

 

Did you confirm pressure? Quite different from flow. Both are important.

 

I guess the carb is my next place to look. I did a spark check to ensure I'm getting spark in the plugs, and yes it sparks on turnover. I'll try the starter fluid again. How do I check the needle valve? The FSM isn't clear on that point, or I'm a dunce and just missing it.

Regards,
Tim

 

I don't a means of testing fuel pressure.

Regards,
Tim

 

The vacuum gauge I own from Harbor Fright can do both. Its not too much money and works well to set idle screws correctly. You need a bright blue spark and not a yellow weak one.

 

It was yellow.

Regards,
Tim