1978 FJ40 2F Idles ok, stalls when trying to accelerate unless high revs and other stuff!!

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

numby said:
Set the points to make certain they're not frozen. Confirm you're hooked up to cylinder No. 1 with the timing light. Lightly loosen the distributor clamp so that you can just barely turn it by hand. Start the vehicle and, with the timing light aimed at the bellhousing window, slightly rotate the distributor CW and CCW until you spot the ball. Be very careful to avoid any moving engine parts like the fan blade, pulleys, or fan belt. Keep your body, hands, and any loose clothing well around to the passenger side of the engine. Put something non-conductive over the battery like cardboard, etc. You've got to be somewhat close with the timing to get it to run well at all. Don't worry about the vacuum advance issue yet.
Click to expand...
Can you do this with the choke pulled slightly as she doesn’t run without it??
Thanks
 
Did a compression test:
Cyl 1 : 137
Cyl 2: 125
Cyl 3: 130
Cyl 4: 130
Cyl 5: 125
Cyl 6: 135

Which I think is good news. I also messed about with the lean mixture to set correctly, but I think I have mucked that out as she is definitely overfuelling now!!
 
So took the air filter off and had a good look at the carburettor nozzles, and only one is squirting liquid when the accelerator is opened up.
What is the best and easiest way to clean this jet?
 
Last edited:
The correct answer is to re-build the carb. Take it apart and clean it. I bought a heated electronic sonic cleaner and a gallon of carb juice designed to use in it - haven't done it yet so can't say how good it is. The chem dip stuff works - I used that stuff like 40 years ago with good results. Having the correct kit is very helpful - as things like gaskets can tear when you take it apart.

You could try carb spray with a pee tube poked right into the jet to try and flush it. Perhaps poking a thin wire into the jet using a hemostat to help you reach it.

Carb work isn't for every one. There are people here that do that job. Someone here did some very good vids on LC carbs - I can't remember his name but you can search for them
 
cmcmill01 said:
So took the air filter off and had a good look at the carburettor nozzles, and only one is squirting liquid when the accelerator is opened up.
What is the best and easiest way to clean this jet?
Click to expand...
Reading more about this, looks like the 2nd venturi does open until the car is flat out, and a vacuum is created!! Thanks @charliemeyer007
 
Nobody has mentioned that this is a Chicom carb, notorious for having junk in them even when they’re brand new. Cleaning it is not guaranteed to solve your problem, but it can’t hurt.

Does your air cleaner fit properly? Your rig would have come with a world market 61011 carburetor, which is about 3/8” taller. I have a couple of the 61011 carbs available for sale, rebuilt by me, if you decide to go that route.
 
Last edited:
Second that. My new china Delco dizzy ran fine for a couple hundred miles. Then the rig started running a little rough. Adjusted the points and then it was back to running good. Another 100 or so miles, running rough again. Looked at the points - they are tweaked out of alignment. Put the old real Delco points and the bigger condenser from wore out Delco in - the rig hasn't run so good in decades.
 
Should there be a gasket between the bottom of the carb and this insulator?
Worried about this red rubbery stuff!!

image.webp
image.webp
 
Definitely don’t want silicone in there; gasoline quickly degrades it.
 
So folks, I decided to go down the route of Petronix Igniter (Kit 91661) and Flame-Thrower 2 coil ( no idea why I did this at the same time as everything else!!), but now the FJ40 turns over but won't start, and also does the odd big backfire from the top of the carburetor!!!

I had to remove the distributor because I dropped a nut down into it, but I marked everything up, so I think it's aligned as before.

The old coil had 2 wires running to it and the ballast resistor, which I have removed both of them and just left the wires to the Igniter and the ignition wire, as per the diagram. There is also a wiring running to the side of the distributor, which I have also disconnected. I haven't traced it, but low resistance to the wire that ran to the negative on the coil!

The resistance looks good from base plate to battery negative, and when I turn on the ignition, I get approximately 10.5v across the coil, which falls to about 8.5v when I crank the engine, which I think looks ok as per the instructions.

Do you have any top tips on what I should do to check? and get it going!

Also, how do you crack the engine from the engine bay!!
 
I would guess you're getting spark because you're getting a backfire thru the carb. I'd confirm the distributor is installed correctly. Put the engine on TDC on the compression stroke and see where the rotor is pointing.
 
/this\
 
pb4ugo said:
I would guess you're getting spark because you're getting a backfire thru the carb. I'd confirm the distributor is installed correctly. Put the engine on TDC on the compression stroke and see where the rotor is pointing .
Click to expand...

See below, I had painted the TDC before!
Does the position of the rotor mean I have not the correct position? Should it be pointing at 4?

IMG_3129.webp


IMG_3130.webp
 
Take another pic with the distributor cap on.

One of the things that Pertronix glosses over is that the trigger often requires resetting the timing. When I install them here, I take it as a given that I am going to have to adjust the timing..
 
Make sure to disconnect and cap the vacuum line to the distributor also while checking and adjusting timing. Cap the vacuum source end, not the distributor port.
 
65swb45 said:
Take another pic with the distributor cap on.

One of the things that Pertronix glosses over is that the trigger often requires resetting the timing. When I install them here, I take it as a given that I am going to have to adjust the timing..
Click to expand...

See the below pictures, also getting a spark tester just to double check I am get a spark still!

IMG_3134.webp
IMG_3133.webp
IMG_3132.webp
 
You must log in or register to reply here.

Share this page

Back
Top Bottom