'69 FJ40 won't start

Joined
May 14, 2021
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CBCO
Hi all,

I'm a long-time lurker, formerly owned a couple 62's and found my dream 40 this spring. Been meaning to intro here for a while, and will soon!

I've driven her a few hundred miles so far without issues, but now she won't start. Got gas, cranks, and will fire up real weak with full choke and pumping the gas. If i take my foot off it dies.

Of course I don't know much about doin stuff and probably shouldn't have bought her but am determined to learn! What is a possible culprit- fuel filter? Dirty tank?

Here's a sneak peek- more to come!

IMG_6995.JPG
 
Joined
Jan 9, 2020
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353
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NorCal
So it WILL start, it just won’t run. Could be a clogged fuel filter. It would be cheap and easy to change and see if it helps. Or could be carb or timing issue. Both of which I have no expertise.

Nice looking 40. Need to see more!
 
Joined
Nov 25, 2014
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767
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Western victoria Australia
If it has the 2 barrel aisan carb, there's a couple of quick things to try. Unscrew the idle/fuelcut solenoid and blow out where it screws in and clean the end of the solenoid.
And make sure it's working [ clicking when powered.]
Another thing to try is unscrew the 14mm lug just below and to the left of the sight glass and probe a air nozzle inside the hole and blow out the primary jet.

Sometimes you can get lucky and find a quick fix.
Good luck.
 
Joined
Mar 10, 2005
Messages
1,277
Location
CT
Not sure for a 69 but ballast resistor, when bad, will allow a start but will not run.

Another possible is the fuel pump is not pumping sufficient fuel.

Sitting for a long time, it usually is clogged filter or lines.
 
Joined
May 14, 2021
Messages
26
Location
CBCO
So it WILL start, it just won’t run. Could be a clogged fuel filter. It would be cheap and easy to change and see if it helps. Or could be carb or timing issue. Both of which I have no expertise.

Nice looking 40. Need to see more!
Right, it won't run. I checked out the filter yesterday and it seemed fuel was dripping from the tank side of the filter, so maybe it is clogged. I'll start with that, and just pinch off the lines on either side of the filter?

Thanks!
 

Blue77FJ40

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Nov 30, 2004
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2,604
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MD
Ascertain the age of the fuel in the tank, as it may be bad. If so, you can drain it through the plug in the tank's bottom, but if you do that, put a new gasket on the plug. Check the inside condition of the tank from the top by pulling out the gauge and use strong light - be careful not to lose/drop any of the small gauge screws. If tank is toast, you can still buy a new one or check out a radiator shop that specializes in cleaning/resealing gas tanks.

It couldn't hurt to check out the soft fuel lines for condition. I found a number of mine were original and rotted. Marine fuel lines are high quality. Off the top of my head, I think stock is 5/16 ID and that's what I used to replace the old lines. Once they are in, disconnect the fuel filter and blow compressed air through the hard/soft lines from the tank to see if they are all clear. If you are unable to be able to hear the compressed air coming out by the end that was attached to the fuel filter, you can put a piece of paper towel in the hose end to see if it gets blown out - that's what I had to do. I'd change the fuel filter anyway, and lay in a supply of spare fuel filters.

You can check the condition of the fuel pump by pulling the top/cover to view the rubber diaphram/gasket as well as the check valves under the diaphram for condition/crud. Before removing the fuel pump cover, make lining up mark to make reassembly easier. There are partitions molded under the cover that must be properly aligned when reassembling (don't ask).

If all the aforementioned checks out, see if the carb view window shows gas at the midline after cranking, then you know you're getting a proper fuel supply. Definitely follow the other posters advice on the idle solenoid. You can query on my prior post in another thread on getting my '40 running again re cleaning out the idle solenoid, the idle mixture screw hole, and the two vents in the carb top with carb cleaner and compressed air-a number of times til all was clear. Good luck
 
Joined
Jan 9, 2020
Messages
353
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NorCal
Right, it won't run. I checked out the filter yesterday and it seemed fuel was dripping from the tank side of the filter, so maybe it is clogged. I'll start with that, and just pinch off the lines on either side of the filter?

Thanks!
I would think you would get more of a stream of fuel instead of a drip. It’s a lot of work (but doable) to go through the whole fuel delivery system from gas cap to carb. Crap in the tank, old lines or even a gas cap that doesn’t vent could be your problem. I was forced to do this when I got my truck due to a leaking gas tank.
 

brooklyn

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May 11, 2007
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704
All good advice, I will add go one step at a time and reevaluate. If you get too many parts pulled apart at one time it makes it much harder and more expensive to resolve.
 
Joined
Jul 5, 2005
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Ames, IA
From your other thread, I saw you have one of those chinese aftermarket carbs. I would bet that is part of the problem. Once you confirm tank is clean and fuel pump is pumping to the carb, I would start looking more closely at that carb and connections. Do you still have the original carb? if so, I would rebuild it and swap it back on.
 

Dizzy

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Santa Fe, New Mexico
Make sure that the fuel-cut-solenoid wire provides voltage when the ignition is on.

Full choke is usually only for starter-cranking, unless the carb has a choke-breaker, which your's, and mine, do not. It will need to idle with about 3/4 choke.

Have you looked at the spark plugs? What about cap and rotor? Fix the fuel leak first.
 

Dizzy

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Santa Fe, New Mexico
I'm pretty sure that you have a vac-retard distributor, which isn't a good fit for that carb/vac set-up. I'd cap the line if it is.

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