Builds Helga: 1966 FJ40 FST (3 Viewers)

[KennyBob]

It should actually drop when you first throttle up, then when holding throttle the vacuum will return. Did this occur?

Sorry I meant that the vacuum increased i.e the gauge went down (counter-clockwise) as I applied throttle. I am not sure. I didn’t hold the throttle and check to see if it returned. I’m more of a noob at this than I realized, lol.

 

[KennyBob]

Well I attached the vacuum gauge to the distributor advance line and saw an increase in vacuum as throttle was applied and held. The vacuum did not return to idle position on the gauge but stayed increased until I let off the throttle.

I also sprayed all around the fittings of both the FD hose and the pcv hose. And for good measure all around the carb again. No changes. I will say it’s a bit hard to tell sometimes though as the engine seems to surge on its own sporadically without any input from me.

 

[77mustard40]

Kenny have you sprayed along the top and bottom of the intake manifold where it mates to the head? It's kinda tough to get to the bottom side. Be careful doing this, have an extinguisher handy, I did it before the engine was warmed all the way up because I was worried about a fire, but that's how I found my leak at the manifold.

 

[KennyBob]

Kenny have you sprayed along the top and bottom of the intake manifold where it mates to the head? It's kinda tough to get to the bottom side. Be careful doing this, have an extinguisher handy, I did it before the engine was warmed all the way up because I was worried about a fire, but that's how I found my leak at the manifold.

Tried my best to spray both top and bottom to no avail. I didn’t notice any obvious signs of a vacuum leak. But as I said, the idle surges without me doing anything so who knows. It may be time to just inspect and replace those gaskets to eliminate the manifold as a culprit.

Something interesting I noticed while tinkering around was that the idle would increase significantly when I detached the hose from the FD fitting on the firewall…

 

[middlecalf]

I’m guessing that you‘re getting too much fuel at idle, hence the idle increase when you created the vacuum leak with the detached FD hose, which is a leaning effect. If the idle would have gotten rough when disconnecting the FD hose then that would point to a more normal fuel delivery at idle with the hose connected.

But then going back through your posts you’re needing to add choke to keep it idling, which is a riching effect. Does your manual choke also bump up the throttle? Just seems like this is struggling going from idle circuit to mid- and high-speed circuits. And I’m rambling .

 

[KennyBob]

I’m guessing that you‘re getting too much fuel at idle, hence the idle increase when you created the vacuum leak with the detached FD hose, which is a leaning effect. If the idle would have gotten rough when disconnecting the FD hose then that would point to a more normal fuel delivery at idle with the hose connected.

But then going back through your posts you’re needing to add choke to keep it idling, which is a riching effect. Does your manual choke also bump up the throttle? Just seems like this is struggling going from idle circuit to mid- and high-speed circuits. And I’m rambling .

Haha no worries man. I dig it. Helps verify the ramblings in my head are correct.

The slight choke now seems to just help it transition from idle to throttle. Without the slight choke it stumbles and bogs a lot harder off of idle. The choke actually slows the rpm’s slightly when it’s applied after warm.

 

[locklaw]

Ok, with the low jet back in, let's look at the pump jet (#9 in the picture below) -

Did you change it or is it large enough for your elevation? I can simulate your symptoms on my 72 by jetting it too small at 4300 ft elevation. Only runs with a bit of choke. As soon as I swop out the main jet (which came in a Keyster kit) for the original, it idles and runs perfectly again.

Easy enough to access from the outside -

 

[KennyBob]

Ok, with the low jet back in, let's look at the pump jet (#9 in the picture below) -

View attachment 3038078
Did you change it or is it large enough for your elevation? I can simulate your symptoms on my 72 by jetting it too small at 4300 ft elevation. Only runs with a bit of choke. As soon as I swop out the main jet (which came in a Keyster kit) for the original, it idles and runs perfectly again.

Easy enough to access from the outside -

View attachment 3038080

No change. Swapped to the “original”, which is smaller. We’re just under 500’ here.

 

[locklaw]

Well poo, we are only really left with check balls and the two air bleeders now, which I suspect you have replaced (check balls) and cleaned thoroughly (air bleed holes).

I am still wondering why you had a hole drilled in the base and if that affected anything, but that is a pure guess.

No change. Swapped to the “original”, which is smaller. We’re just under 500’ here.
View attachment 3038224

 

[KennyBob]

Check balls for sure. Where are the air bleeder holes? I’m sure they’ve been cleaned but I’ll double check to make sure.

 

[KennyBob]

I went ahead and replaced everything I took out after cleaning it for s***s and giggles. Still no noticeable difference. Although I noticed this time around the massive vacuum leak I create with the FD hose does make it bog down a bit.

I also noticed I’m missing the strainer between the check valves.

 

[locklaw]

Check balls for sure. Where are the air bleeder holes? I’m sure they’ve been cleaned but I’ll double check to make sure.

#1 and 2

This is the theory of operation-

 

[KennyBob]

#1 and 2

View attachment 3038678

This is the theory of operation-

View attachment 3038679

Thanks @locklaw. I’ll see if I can make sure those are clean and clear. As always any advice on ways to do that is much appreciated.

In an effort to eliminate any vacuum leaks, I’ve ordered this nice looking kit from Remflex. TOYOTA Header/Exhaust Manifold Gasket - http://catalog.remflex.com/TOYOTA_Header_Exhaust_Manifold_Gasket_p/7026.htm

However, upon inspection of the manifolds I noticed the outer two exhaust studs appear to be sheared off at the manifold. Does anyone have a source for some new ones?

 

[middlecalf]

The early 1F motors just had studs, nothing else for those two outer locations.

 

[KennyBob]

The early 1F motors just had studs, nothing else for those two outer locations.
View attachment 3039890

Any idea who might have them off hand?

 

[77mustard40]

Might check SOR, IIRC I picked up a couple of manifold studs from them for my 40. But that was a long time ago. If you have one available you might try Austin Bolt off Metric,.

 

[middlecalf]

Meant to also post the part number, it’s 90116-10046 (for a ‘65) just in case one of the overseas parts hounds might have access to them. I don’t know of anyone who does though. GL.

 

[KennyBob]

Meant to also post the part number, it’s 90116-10046 (for a ‘65) just in case one of the overseas parts hounds might have access to them. I don’t know of anyone who does though. GL.

Interesting. That number appears to cross reference to a Dorman 03105… Easy and cheap enough to give them a shot. Thank you sir!

 

[KennyBob]

Might check SOR, IIRC I picked up a couple of manifold studs from them for my 40. But that was a long time ago. If you have one available you might try Austin Bolt off Metric,.

I look at SOR first to no avail. They seem to not have them for earlier than 67 or 69 I forget which. I have no idea if they’re interchangeable or not. Thanks!

 

[KennyBob]

The early 1F motors just had studs, nothing else for those two outer locations.
View attachment 3039890

I need to get myself a copy of that fsm… What I have doesn’t have that diagram.