86 FJ60 having a stumbling or lurching problem

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May 20, 2019
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Location
Denver, CO
Hey guys, just bought a 1986 FJ60 that was pretty much worked over by classic cruisers in October 2016. Almost everything on this rig is well sorted out except... We live in Denver and took it to Moab, well tried, but in Glenwood, after a stop for breakfast, the rig started like lurching or, as I have read on here, maybe stumbling.

Ran through quite a few diagnostics on the roadside with the help of 4Wheelers in Glenwood and eventually just plugged the top hose going to the EGR valve. Seems to have worked a bit but every once in a while it lurches or stumbles again. Now its got a new (used) fuel tank, filter, and pump, newer air filter, all from its classic cruisers trip and we took apart the top half of the carb and cleaned it (was a little dirty but not bad). I do have to say I only get about 10-12 MPG which I feel is a little low for a recently tuned engine (again 2016, new plugs, wires, and such). When I start it up and start driving it almost sounds like the engine isn't getting enough fuel or air or something, (kind of whining at higher RPS) Does it sound like I have a bigger problem lurking somewhere?

I know these things have personality, and that these mountain passes will kill my mpg but its almost like my engine doesn't have the power it should and the potential gas/air problem is kinda bugging me as well as the stumbling. Just want to take care fo the truck and spend many many more years together.

Any input appreciated!
 
In my experience, a lurching engine isn't get enough fuel. Although you've gone through & cleaned out the upstream fuel system and the float bowl, there could be junk clogging the tiny fuel strainer before the needle valve or a piece of junk blocking the primary jet.

My advice at this point would be to have the carburetor disassembled and thoroughly cleaned out. Washing out the float bowl is good, but Mr Dirt might be deeper inside -
Also make sure the carb accelerator pump squirts fuel with gusto when pumping the gas.
 
In my experience, a lurching engine isn't get enough fuel. Although you've gone through & cleaned out the upstream fuel system and the float bowl, there could be junk clogging the tiny fuel strainer before the needle valve or a piece of junk blocking the primary jet.

My advice at this point would be to have the carburetor disassembled and thoroughly cleaned out. Washing out the float bowl is good, but Mr Dirt might be deeper inside -
Also make sure the carb accelerator pump squirts fuel with gusto when pumping the gas.

So Carb rebuild kit and completely clean out that sucker? I can do that.
 
I did an impromptu cleaning last week. I pulled the lid off (be careful to not tear the gasket) and cleaned the bowl and jets out with carb cleaner.

If fixed my problems. It was a side of the road style repair, but in my driveway.

I stay on my fuel filters frequently and it still get gunk from the tank.
 
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I did an impromptu cleaning last week. I pulled the lid off (be careful to not tear the gasket) and cleaned the bowl and jets out with carb cleaner.

If fixed my problems. It was a side of the road style repair, but in my driveway.

I stay on my fuel filters frequently and it still get gunk from the tank.
When you say pulled the lid off you mean the air horn or the air cleaner lid?
 
When you say pulled the lid off you mean the air horn or the air cleaner lid?
Air horn. I took the JIS screws off the lid and opened the carb.
 

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