New Engine for a 1975 FJ40 Named "Sandy" (1 Viewer)

[MatthewMcD]

"vacuum valve."

The grey can that is vacuum activated on the left side of the picture. I don't know the proper name the FSM calls it the Throttle Positioner diaphragm.

 

[Pighead]

The grey can that is vacuum activated on the left side of the picture. I don't know the proper name the FSM calls it the Throttle Positioner diaphragm.

It's a vacuum diaphragm, there's lots of them on later LandCruisers. I don't trust them and I don't like them. They're why I won't run a later carb.
My throttle positioner didn't work, probably due to a bad diaphragm, and I decided that I did not need a vacuum-operated throttle positioner, I like to think of my right foot as my throttle positioner. So I took it off, plugged that port and run it. Haven't missed it. Don't do what I do, I'm an idiot. I also disabled my fuel cut-off solenoid.

 

[Pighead]

@Pighead It isn't an idle speed, it is an amount of throttle opened when the starter is cranking. The FSM has you open it to a certain amount, and that is that number on a warm motor.

I see. Thank you.

 

[MatthewMcD]

Both the Choke Breaker and the Throttle Positioner are operated by the vac at the carb base. I'm not sure about a "vacuum valve." Those links can be bent, but, the adjustment for the Throttle Positioner is the rpm-adjusting screw, and the Choke Breaker is set with the link so that it opens the choke butterfly 38 deg. from bore, according to factory specs.

Basically, you probably need to do nothing other than make sure that the adjustment screw tip is riding on the throttle valve lever, and make the engine run at the right rpm.

@Pighead It isn't an idle speed, it is an amount of throttle opened when the starter is cranking. The FSM has you open it to a certain amount, and that is that number on a warm motor.

Thanks for the clarification. I'll have another look at the function of the Throttle Positioner adjustment.

 

[Grayscale]

I just looked at my '75 USA carb. I took it off just after rebuild because I bought a new carb, so it was exactly how I had it run when I perfected the settings. I never had the Throttle Positioner screw even touching the throttle valve lever. I had it entirely working on the fast-idle as the setting for the starter-cranking throttle-blade opening. I really liked the set-up before I changed carbs. I know that the factory literature wants you to depress the accelerator pedal when you start-up, but, I simply let the closed choke and the choke's fast-idle start the engine, because it does it evertime without the TP to open the throttle, or the driver to use their foot on the gas.

 

[Grayscale]

Although I like the minimalism of Pighead's carb, Mark sent you a jewel as far as two-barrel F or 2F-carbs go. I realize that the linkage and all the functions get kinda heavy, but, once I saw the start-up sequence, I was amazed how the whole system works without the driver having to receive feed-back from the motor in order to 'feather-in' the choke button on the dash.

 

[MatthewMcD]

Although I like the minimalism of Pighead's carb, Mark sent you a jewel as far as two-barrel F or 2F-carbs go. I realize that the linkage and all the functions get kinda heavy, but, once I saw the start-up sequence, I was amazed how the whole system works without the driver having to receive feed-back from the motor in order to 'feather-in' the choke button on the dash.

Agreed, I didn't realize how it was all supposed to work until now. Cool how the engineers use vacuum as a signal.

 

[65swb45]

Well...you may have gathered that my truck is running on the new carb. It's running GREAT! It's quieter and smoother than ever. I dialed in the carb and the performance is amazing, no more off-idle hesitation, it's very perky for a tractor.

I ran it around the block a few times and it is running great.

In setting the carb I started with the Idle Mixture screw out 2 turns and then crept it out as long as the RPMs kept climbing. It topped out at 3 turns. I set the idle at 600ish and verified the fast idle setting. I wasn't quite clear on the Throttle Positioner instructions, but now that I wrote out the question, I think I understand how it is supposed to work.

I'll drive it this way for a while to get a feel for the carb. The truck is running (and sounding) great.

I am glad to hear/ read that all is running well. A clean carburetor will almost always outperform a dirty one. I am though more than a little concerned since your posts indicate you are still rounding up parts for a new fuel line, and that you have bent your old line in the meantime. THAT is a classic case for breaking shellac loose inside the line which will gum up the ports in the new carb.

I suggest that if you are satisfied with the settings you not run it any more until the new line is installed, and then run it long enough to make sure (as sure as you can be without looking inside) that nothing bad has gotten in. As I told you when you were here, @Spike Strip rebuilt carb lasted exactly 20 minutes before contamination plugged the idle circuit, which fortunately was exactly how long we needed to seat the rings on his rebuilt engine.

The goal: 20 in 20. Twenty inches of vacuum in 20 minutes. We got 19 before we had to shut er down.

 

[MatthewMcD]

I am glad to hear/ read that all is running well. A clean carburetor will almost always outperform a dirty one. I am though more than a little concerned since your posts indicate you are still rounding up parts for a new fuel line, and that you have bent your old line in the meantime. THAT is a classic case for breaking shellac loose inside the line which will gum up the ports in the new carb.

I suggest that if you are satisfied with the settings you not run it any more until the new line is installed, and then run it long enough to make sure (as sure as you can be without looking inside) that nothing bad has gotten in. As I told you when you were here, @Spike Strip rebuilt carb lasted exactly 20 minutes before contamination plugged the idle circuit, which fortunately was exactly how long we needed to seat the rings on his rebuilt engine.

The goal: 20 in 20. Twenty inches of vacuum in 20 minutes. We got 19 before we had to shut er down.
View attachment 3806178

I had a feeling you'd mention that. I did flush carb cleaner through the hard line (after bore brushing what I could reach). I have ordered new fittings for the new hard line I plan to install before running it again.

As for the break-in procedure I was supplied with break-in oil. (Driven BR30) I was told to run it at 2000 RPM for 20 minutes then shut it down and let it cool. Then do it again for another 20 minutes. Then change the oil and filter, refill with a hi-zinc oil.

 

[MatthewMcD]

The goal: 20 in 20. Twenty inches of vacuum in 20 minutes. We got 19 before we had to shut er down.
View attachment 3806178

In this photo, which vacuum port are you connected to? I assume it's the one next to the mixture needle.

 

[Pighead]

I assume it's the one next to the mixture needle.

I'm guessing it's off the intake manifold...

 

[Spike Strip]

Intake manifold. You want manifold vacuum. Ported vacuum (on carb) will give readings the opposite of manifold vacuum. On the FJ60, there's a port off the fitting for the brake booster vacuum source for A/C idle up. Not sure what manifold vac ports are on the manifold you're using. You may have to install one.

That rebuilt 2F runs great, almost 15 years later. 21 Hg at 750 idle. Still running the Mark A rebuilt carb. Was damn glad to have Mark there.

Nice work on your truck, too!

btw, this was all it took to kill the carb:

In this photo, which vacuum port are you connected to? I assume it's the one next to the mixture needle.

 

[MatthewMcD]

Intake manifold. You want manifold vacuum. Ported vacuum (on carb) will give readings the opposite of manifold vacuum. On the FJ60, there's a port off the fitting for the brake booster vacuum source for A/C idle up. Not sure what manifold vac ports are on the manifold you're using. You may have to install one.

That rebuilt 2F runs great, almost 15 years later. 21 Hg at 750 idle. Still running the Mark A rebuilt carb. Was damn glad to have Mark there.

Nice work on your truck, too!

btw, this was all it took to kill the carb:

View attachment 3806375

Thanks, yes, I have a port for the brake booster I have been using, was just checking to be sure.

 

[77mustard40]

Thanks, yes, I have a post for the brake booster I have been using, was just checking to be sure.

Matt that's where I have connected a gauge in the past

 

[MatthewMcD]

The next item on my "Will it work on my new engine" checklist is the fan.

My old engine has a fixed metal fan. The new engine has a fluid clutch and plastic fan.

I measured the new fan and it's very close to 18" in diameter. I struggled to get a perfect measurement of the radiator shroud, but it appears to be about 18". Are the shroud and fan measurements "standard". Here is the old fan on the old engine. (After a little lipstick.)

Most importantly, IF the new fan does not fit it the shroud, is there any issue running the old fan while I get these issues sorted out? (I'll be "borrowing" the space for the engine swap and don't want to have the truck idle for a month. I am doing my best to think (and order) ahead.)

 

[mrboatman]

You can run a plastic clutch fan with a F engine shroud. You will just need to use a 2x4 and BFH to make room near the bottom. I have been running this combo for years. You can also just get a 2F fan shroud.

 

[Pighead]

The new fanclutch may not (probably won't) bolt right up to your old waterpump. You can swap the flange on the waterpump to the new style.

 

[MatthewMcD]

The new fanclutch may not (probably won't) bolt right up to your old waterpump. You can swap the flange on the waterpump to the new style.

I'll be mounting it on the new engine with a new water pump.

 

[MatthewMcD]

You can run a plastic clutch fan with a F engine shroud.

How can I tell if it's an F or 2F shroud? The chassis is 5/75 so it's "mostly" set up for a 2F, but there are a few differences and missing parts. (Part of the reason for this pre-build planning.)

 

[Skreddy]

Sorry if I missed it. Make sure you have new or good used engine mounts. If the fan is tight and you hit a bump with old mounts the engine can move a little and self-clearance the fan on the shroud.

Looking good! Glad to see you got a carb from Mark and dialing things in on current engine.