destins 1964 fj40 FST restore thread

[fj404life]

Experimented with timing adjustments? Sometimes old motors like something other than the text book setting. I like to set it by ear then use the light and tweak from there.
I dunno...just a wild guess really.

 

[destin]

Experimented with timing adjustments? Sometimes old motors like something other than the text book setting. I like to set it by ear then use the light and tweak from there.
I dunno...just a wild guess really.

yeah I did try advancing it, and the stumble felt like it went away, but then i would get occasional backfires and stumbles.. in a certian range, just kinda weird.

There has to be something up

I will check the head bolts, rocker arm bolts and valves soon.
Maybe that is the problem

I do not think it is contaminated gas as i flushed the tank and the filters seem ok.

 

[waiting for time]

If the valves are off you will have a bumpy idle and the performance on high demand wil he less. Unless they are realy off they will not have much influence on the revs between 750 and 3000 rpm. This is why I don't think your problem is in there.
Ignition timing can do this. If the vacuum enhancer is stuck or the ground plate in your dizzy it will stumble when accelerating (or revving) and then run oke when stop accelerating. You can test this by sucking on the vacuum hose from carb to dizzy. Take off the distr.cap and look if the base where points are mounted on rotates a bit and clicks back when released. If that all works focus on the carb, fuell pump doesn't seem to be the problem, if it was that the engine would stall. You cab check the level in the carb if that is to specs. If the level is to low you can get the same problem you have now, bad pick up in the low to medium range, also not good for your engine.

Good luck

 

[destin]

If the vacuum enhancer is stuck or the ground plate in your dizzy it will stumble when accelerating (or revving) and then run oke when stop accelerating. You can test this by sucking on the vacuum hose from carb to dizzy. Take off the distr.cap and look if the base where points are mounted on rotates a bit and clicks back when released.

Good luck

how does the vacuum enhancer get stuck on the ground plate?
So if you suck on the hose from the vacuum advance, you see the base where the points are mounted more slightly>?

If the do not move that means the ground plate where the condenser and points ground is rubbing on that bottom bit?

Thanks again

 

[waiting for time]

how does the vacuum enhancer get stuck on the ground plate?
So if you suck on the hose from the vacuum advance, you see the base where the points are mounted more slightly>?

If the do not move that means the ground plate where the condenser and points ground is rubbing on that bottom bit?

Thanks again

There are a few things that can go wrong here.
one is that the membrane in the enhancer is torn, this also leads to a vacuum leak. The other is the leaver gets stuck in the enhancer ( not so common ). Then you can have dirt between the 2 plates. You can also have bolts that are to long to mount points and/or condensor. And of corse the corrosion on the pivot points for the plate.
In the lower part of your distr. there is also an enhancer which works with litle weights being pushed outside (don't know the English word for it) so they will enhance the ignition when the revs go up. This however does not seem to give your problems.

You best start with finding out if the mount plate moves.

Good luck.

 

[destin]

There are a few things that can go wrong here.
one is that the membrane in the enhancer is torn, this also leads to a vacuum leak. The other is the leaver gets stuck in the enhancer ( not so common ). Then you can have dirt between the 2 plates. You can also have bolts that are to long to mount points and/or condensor. And of corse the corrosion on the pivot points for the plate.
In the lower part of your distr. there is also an enhancer which works with litle weights being pushed outside (don't know the English word for it) so they will enhance the ignition when the revs go up. This however does not seem to give your problems.

You best start with finding out if the mount plate moves.

Good luck.

thanks man i will take a look at this hopefully later today.
The distributer is new, but ya never know if s*** is wonked up.
I also noticed some clearish/white lubricant in the top part where the rotor attached to the hex top of the distributer. Should that be replaced periodically to help with conductivity? What is the stuff made of? Is it the grease you get in the point kits?

I have to unfortunately work this weekend to afford the extra bits for the cruiser

I knew next to nothing about cars before i started taking this one apart, so baby steps and alot of dumb questions

 

[dmaddox]

Destin,

I may have a solution for you in addition to the timing suggestions.

On my F135, I had a very similar problem to yours. Mine started when i took off my 1967 carb (with idle solonoid) and put on my blue window carb. I was wondering how on earth a rebuilt carb would cause this issue. I had no power off the line, but when the RPM's picked up it was ok.


I noticed on your two carbs (in the picture you had them side by side), you have different spacing on the lifter rod.

The lifter rod controls the throw on the plunger. This will make more sense by looking in a scanned section of the F engine manual. Figure 4-13:

Please then refer back to the picture youposted of the two carbs side by side you took earlier, and look closely at the lifter rod on the carb:

You have the one on the left "pinched" more than the one on the right. That lifter rod, when set incorrectly will cause the exact issue you are having because it's hooked to the bottom of the pump plunger (fig. 4-12) - which pumps fuel into your bowl.

In my situation, I had a perfect idle. But the second I gave it any gas - it was major hesitation and no power until i SLOWLY opened up the throttle (not too cool if you just got a green light at an intersection).

Refering back to your photo's, again look at the one on the left. That one will plunge more fuel than the one on the right.

Now, you may be wondering how to adjust this. To adjust this, here is what you do:

I followed this from the F engine manual (from our era, the F135) and I never had the problem again.

Take into consideration I set everything as per the manual, and then I adjusted idle speed and mixture after that.

I hope this helps.

Good luck bud,

-dallas

 

[destin]

Hey Dallas!

Damn that seems to be EXACTLY my problem man!

s***e, so basically my step up rod height has been shorted as someone may have bent the throttle connection link eh?

I am not sure i fully understand how to set that step up road hight spec based off the last page...
( i understand i need to bend the throttle connection link to effectively lengthen or shorten it )
But just adjust it by eye?

Thanks Dallas!

 

[dmaddox]

figure 4-32 is what you need to concentrate on.

As you can see, if you have #2 pinched too much, or #1 bent too far down, too much fuel will get into the bowl, and the needle will not let enough out through your jet.

So to adjust this, you have two settings. #1 is the setup between the needle and the jet. #2 is how far/how much the plunger goes up and down.

What I think you have going on is that that clip is bent too much, not allowing the needle to come out enough, and the plunger pushing too much fuel in.

Regardless, those two settings will likely solve your problem. I mean, you can clearly see the difference between your two carbs - the trick is adjusting so that you have correct clearances on both the plunger and the needle.

Let me know if you need a hand.

-dallas

 

[dmaddox]

it also controls the butterfly in the throat. - that has an impact too.

You are close - just need to dial in the adjust ments.

 

[destin]

thanks bro

Hopefully i can make enough progress at work to be able to steal away to the shop and fiddle with my rig this evening

Thanks man!, i report back later when i get results

 

[fj404life]

fingers crossed for ya!

 

[waiting for time]

fingers crossed for ya!

2X for me to

 

[destin]

thanks guys

 

[destin]

so the one on the left is the currently installed one ...

which means because it is pinched more it would be delivering more fuel...
So having it deliver less fuel would help the stumble at low rpms?

 

[dmaddox]

Yes and no. In figure 4-32, note that if you have it pinched together more, the needle will not "lift" out of the jet as much, which in turn would cause the stumble.

There is a three-way combo going on here with those two adjustments.

1. The step-up rod 2. The plunger and 3. throttle valve.

-dallas

 

[destin]

ah ok gotcha

so basically my throttle valve flap is aligned just like this: ( figure 4-31 )
this is when the throttle scree is not applied and in its rest position.

But my problem is more about the metering height more than anything less correct? if anything my metering rod is "too short" to put it in simple terms, and never unseats out of the metering valve enough... correct?

 

[destin]

here are some images:

here is the defualt position with the throttle screw backed out:
( covers the tip of the figure eight hole

more defualt settings of the plunger and meter rod, default position

here is the meter rod out...

Now should at full throttle that skinny part ( the highest part that tappers up to the top of the rod ) seat it self with the metering check valve?

How can I determine its proper default state ( idle ) and wide open state ?

I jsut want to know how much to bend the throttle linkage (1) or the top of the metering rod rocker (2)

Thanks, let me know if I am totally crazy here, not too sure of what i am doing

 

[dmaddox]

I would start with the simple test of using two needle nosed pliers and adjusting the #2 in that photo "more straight".

Notice a difference?

As I was trying to take my sunday nap...I also remembered the leather flap on the plunger - make sure it's not getting caught on that gap (you'll see what Im talking about if you look down the sleeve of where the plunger goes up and down) and that the operation of the throttle is nice and smooth.

-dallas

 

[destin]

ok so adjust number two int the photo more straight, but not so much the leather part of the plunger goes above the slot from the bowl to the accelerator pump right?

The metal part can exceed the slot between the fuel bowl and the accelerator pump, but not the leather?

Thanks man!