76 fj 40 carb troubles

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Jun 2, 2011
Castle Rock CO
I just purchased this 40 and overall it is great shape. The carb has some choke or adjustment issues. It only runs with choke 1/2 way out. It has all the original equipment. What are the likely causes? vacuum, jets, ??? Should I convert to a Weber?

I know I've seen some discussion on this topic, but nothing that matches my situation 100%
Have you tried the carb cleaner spray trick to look for vaccuum leaks? Start with the basics. Move up from there. Can you keep it running with the choke closed if you keep the rpms up? How old is the gas?

I am a fan of the original Aisan carbs. They are actually really easy to rebuild. Almost every one I have ever done the secondary vacuum diaphragm is shot.

Find the problem. If it is really the carb and you don't want to rebuild it send it to Jim C. He does good work.

Use the search tool its is your friend.

:flipoff2: welcome to the addiction.
I kinda have the same problem.Tomorrow I will change my fuel filter and air cleaner filter. I will check my spark plugs and timing then do a propane leak test. If that doesnt fix it then my carb is going to meet mark.
You can do a search and find a ton of info on this topic. Check if you have vaccum leaks, Manifold/intake to block are know to leak. Spray carb cleaner or WD-40 at the base if revs up you got a leak. Make sure all your hoses are connected correctly. If you have a egr in it make sure that circuit works. Check your cutoff solenoid, make sure it's actuating and has an O seal on the end. You may have several things that need to be taken care of. If it has been sitting to long it just may need the carb to be cleaned If so there are several vendors on this board that rebuild them. I would not go the weber route, the Toyota carbs are just as good if not better. All mine work as advertised. Once you get it going they are very dependable. Find a Toyota factory manul if don't already have one. They are a huge help.

I bought a 79 and it had the same issue. The previous owner was an electrical engineer and he decided to silicon the EGR valve to by pass it and tweaked on the carb to get it to pass inspection. When I got it I did not know this.......what it really needed was to take the carb apart and soak it. It had one of circuits in the carb clogged. Once I got that part taken care I had to undo what the PO did.
Thanks for the words gents. I'm half afraid the wrong guy got a hold of it prior to my purchase. I'll do some more searching and try your tips. This is my first forum- I have some things to learn. BTW- how do you post a picture with your ID?
Choke halfway out usually means a vacuum leak...
1. Do a thread search on the idle/ fuel cut solenoid and test yours.

2. Determine
a. What is the lowest RPM at which the motor will run [requires tach]
b. What is the vacuum at that RPM? [requires vacuum guage]
c. Determine if there is gas dribbling out of the primary emulsifier[nozzle]
d. Describe whether exhaust is running rich or lean.

This should be a proscribed checklist for EVERYONE posting about carb troubles. IT would make it a lot easier for folks here to help ANYONE diagnose and repair their rigs.


Mark A.
This should be a prescribed checklist for EVERYONE posting about carb troubles. IT would make it a lot easier for folks here to help ANYONE diagnose and repair their rigs.


Strongly agree w/ Mark A's statement.

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