fjc-man
SILVER Star
mbb, you never covered the functionality of your centrifugal and vacuum advance. These two can create emissions issues as well.
Has it been two years already--Failed Smog this time
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how much was the rebuild at B-Z Rebuilders for the Air pump? My new 60 is still smogged and I may keep it that way..
fjc-man
SILVER Star
I think it’s currently like 250. Pretty quick turnaround too.
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- #24
Thanks for the picture Spike. Those SSTs are really cool. The one with actual pressure measurements does confirm what I found in a Toyota technical document that “good” starts at 2 PSI. When you measure a pump about where on the scale does it read? My pumps are reading just a little more than 2 at 1200 RPM. Thanks.
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- #25
BZ recently charged me $280 including return shipping. The turn around time for the rebuild is one day. They do need you to send a rebuildable core.
I don't use them. They'd been banged up pretty good before I got them, the one with the measurements has no cover glass for the dial, so I don't really trust their accuracy, but they were in the low-green area when I tested. When I test now, I just lightly put my thumb over the hose end to the Air Rail, and if it blows past, it's generally enough.
The little bit I understand about the air pump…. It’s a rotary vane pump and the vanes are a carbon composite of some sort.
The vanes scrape along the inner bore to push air in a certain direction. If the vanes don’t seal perfectly (not broken in yet) they’ll allow air to leak past which will lower the pump’s output psi.
If the rebuilder or manufacturer recommends a 500 mile break in, that’s probably why.
Maybe drive the vehicle some more to break in the pump.
The vanes scrape along the inner bore to push air in a certain direction. If the vanes don’t seal perfectly (not broken in yet) they’ll allow air to leak past which will lower the pump’s output psi.
If the rebuilder or manufacturer recommends a 500 mile break in, that’s probably why.
Maybe drive the vehicle some more to break in the pump.
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- #28
Well I'm pretty sure the vacuum advance is working. At least applying vacuum to either diaphragm will rotate the distributor plate. And the truck drives fine, no pinging or stuttering under load. I don't have a timing light with an advance mechanism to be more quantitative.
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- #29
Just an update here. I haven't gone back yet for a 4th test...
I removed the skid plate and measured the exhaust temperature immediately after pulling a long hill at 65mph. The exhaust pipe temperature was about 750F. The front of the CAT was 850F and the rear of the CAT was about 950F. The muffler was about 600F. Because the CAT is at a higher temperature that increases front to back I'm assuming it is doing some reaction. I don't know what the temperatures should be, though.
I also took off the vacuum piping manifold, brushed it off and blew out the tubes with compressed air. I don't see any holes are cracks and no tubes were clogged, so I put it back on.
The emissions manual indicates one of the conditions of poor gas mileage is a power valve stuck open. The power piston is pulled up under conditions of "high" vacuum. when vacuum decreases (under high load conditions), the power piston drops and opens the power valve--I think this is how it works. My power valve does seem to open and close (it is not "stuck"). I can also get the power piston to pull up is I apply vacuum to the power piston chamber. The vacuum source is a port just below the primary throttle plate. This vacuum source is used for both the power piston as well as the choke breaker. At idle, I can measure the vacuum presented to the choke breaker and it seems to be high enough to keep the power piston up and power valve closed. I can also see that the choke breaker will stroke when I connect/disconnect the vacuum hose. My general conclusion is the power piston and valve are working properly. If anyone has comments or knows of a real test procedure for the power valve, please post.
I have the carburetor disassembled (again). Before I put it together I think I will put back in the OEM 1st and 2nd main jets (size 147 and 200 respectively). I had replaced these is similar sized Mikuni jets (size 147.5 and 200) as discussed in another thread
Thanks!
I removed the skid plate and measured the exhaust temperature immediately after pulling a long hill at 65mph. The exhaust pipe temperature was about 750F. The front of the CAT was 850F and the rear of the CAT was about 950F. The muffler was about 600F. Because the CAT is at a higher temperature that increases front to back I'm assuming it is doing some reaction. I don't know what the temperatures should be, though.
I also took off the vacuum piping manifold, brushed it off and blew out the tubes with compressed air. I don't see any holes are cracks and no tubes were clogged, so I put it back on.
The emissions manual indicates one of the conditions of poor gas mileage is a power valve stuck open. The power piston is pulled up under conditions of "high" vacuum. when vacuum decreases (under high load conditions), the power piston drops and opens the power valve--I think this is how it works. My power valve does seem to open and close (it is not "stuck"). I can also get the power piston to pull up is I apply vacuum to the power piston chamber. The vacuum source is a port just below the primary throttle plate. This vacuum source is used for both the power piston as well as the choke breaker. At idle, I can measure the vacuum presented to the choke breaker and it seems to be high enough to keep the power piston up and power valve closed. I can also see that the choke breaker will stroke when I connect/disconnect the vacuum hose. My general conclusion is the power piston and valve are working properly. If anyone has comments or knows of a real test procedure for the power valve, please post.
I have the carburetor disassembled (again). Before I put it together I think I will put back in the OEM 1st and 2nd main jets (size 147 and 200 respectively). I had replaced these is similar sized Mikuni jets (size 147.5 and 200) as discussed in another thread
Thanks!
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For general reading about the function of power valves in carburetors, the link below has some interesting information about power valve functioning in a Holley carburetor.
Granted we don’t have Holley carbs in the FJ60 and the article is talking about things specific to that Holley, but there’s still some good nuggets of info about how power valves work in all carburetors.
www.racingjunk.com
Granted we don’t have Holley carbs in the FJ60 and the article is talking about things specific to that Holley, but there’s still some good nuggets of info about how power valves work in all carburetors.
Choosing the Right Power Valve for Your Holley Carburetor
When it comes to tuning, the power valve has always seemed a mystery to many. But, once you know how power-valves work, it’s easy.
www.racingjunk.com
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- #31
Well, I finally passed...on the fifth attempt. I had some family stuff to attend to so I wasn't working on this issue for the past few months. Before my registration expired in July I went into AAA (I am a member) and paid the registration fee. I went back in to AAA today with the passing smog result and the AAA guy gave me my registration paperwork and sticker. Because I paid my registration "on time", I didn't have to pay a late fee.
To get the passing result on 11/4/2024 shown above, I installed a new catalytic converter Magnaflow 3391894 (CA CARB compliant). This is supposed to be a direct fit for all years of the FJ60, however I as documented in this thread my cat temperature sensor was too long for the probe port and it touched the ceramic matrix before the sensor flange bottomed out on the port flange. I made a spacer to allow the installation of my probe. When I talked to the manufacturer about this they said there was a change in probe length in 1981 and neither of their catalytic convertors would work with the later probes. They also said they would be revising their catalog to remove the FJ60 applicability post 1981. This would be unfortunate as there are not that many options available for us California registered owners.
Although I did have my air pump rebuilt at B-Z rebuilders in Canoga Park, CA, it seems my air delivery is still a little bit low as there was no residual O2 at the 25mph test point. I have two pumps, both freshly rebuilt and both seem to barely meet the requirements for air delivery as described in the emissions manual (discussed somewhat in earlier posts). Perhaps my AI check valves are too restrictive although the manual just says to check for flow/no flow without details on break open pressures, etc.
Thanks to everyone that has helped me so far through this. Please post up with comments or further recommendations. Thanks.
To get the passing result on 11/4/2024 shown above, I installed a new catalytic converter Magnaflow 3391894 (CA CARB compliant). This is supposed to be a direct fit for all years of the FJ60, however I as documented in this thread my cat temperature sensor was too long for the probe port and it touched the ceramic matrix before the sensor flange bottomed out on the port flange. I made a spacer to allow the installation of my probe. When I talked to the manufacturer about this they said there was a change in probe length in 1981 and neither of their catalytic convertors would work with the later probes. They also said they would be revising their catalog to remove the FJ60 applicability post 1981. This would be unfortunate as there are not that many options available for us California registered owners.
Although I did have my air pump rebuilt at B-Z rebuilders in Canoga Park, CA, it seems my air delivery is still a little bit low as there was no residual O2 at the 25mph test point. I have two pumps, both freshly rebuilt and both seem to barely meet the requirements for air delivery as described in the emissions manual (discussed somewhat in earlier posts). Perhaps my AI check valves are too restrictive although the manual just says to check for flow/no flow without details on break open pressures, etc.
Thanks to everyone that has helped me so far through this. Please post up with comments or further recommendations. Thanks.
fjc-man
SILVER Star
Have you put 500+ miles on the rebuilt air pump? That is the break in for internal parts for optimum output.
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- #33
not yet. I'm only put on about half that. I will drive it some more then go back and retest the air pump output. Thanks.
Personally, I think the Magnafuk BS about probe length is BS. I have a bunch (mostly non functional), and they're all the same, though the part number does change at the 5/85 change-over date. I have noticed that some have a longer CABLE, but that's it. The late 40 series and 55 have this probe with different part #s also though I've never seen any.
I think MF just F'd up and don't care. My earlier Magnaflow direct-fit CARB CAT with the same part # as current one, the sensor fits fine.
The O2 numbers are also affected by the gas you're using - Generally summer blends are heavily oxygenated, Winter blends, much less (at least here in the AQMD). And this all may be moot eventually as Newsom and Co continue to drive refiners out of Kalif.
Glad you passed.
Vote for you-know-who
I think MF just F'd up and don't care. My earlier Magnaflow direct-fit CARB CAT with the same part # as current one, the sensor fits fine.
The O2 numbers are also affected by the gas you're using - Generally summer blends are heavily oxygenated, Winter blends, much less (at least here in the AQMD). And this all may be moot eventually as Newsom and Co continue to drive refiners out of Kalif.
Glad you passed.
Vote for you-know-who
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- #36
I agree that the probe length issue is BS. They have been selling this Cat for some years and it doesn’t make sense that I’m the first one to have a problem. The ceramic matrix is only about half the length of the cylindrical section so there is some flexibility where it is installed. I asked them to share their fabrication drawing with me but they declined.
At this point, that Thermosensor is superfluous anyway. Its function has nothing or very little to do with emission since modern CATs run cooler than the old brick giant pre-OBD CAT. The Smog-NAZI requirement that the CAT be OBD-II compliant is big BS too as that just means the PCM is capable (thru O2 sensors fore and aft of the CAT) of telling the health of the CAT. That really does our FJ60s a lot of good. 
It's just a way to squeeze more green out of us.
It's just a way to squeeze more green out of us.
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