Fj60 running rough need help!
- Thread starter SDH
- Start date
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Quick questions on the carb rebuild...
You did the carb rebuild yourself?
If so, what kit did you use?
And the carb is the OEM Aisin carb?
Do you know what size jets were in the 1st and 2nd (before the rebuild)?
And after the rebuild, what size jets are in there now (and did they come with the kit)?
- Thread starter
- #64
Yeah! home re-build.
Keystone kit from kurt with extra diaphragm.
OEM Aisin carb
Jets said 1.47 main 2.00 secondary. Pretty sure!
I reused the original jets. They came out clean (not stripped).
Thinking of putting in the 1.36/1.80 somethings from earlier 40's?
Keystone kit from kurt with extra diaphragm.
OEM Aisin carb
Jets said 1.47 main 2.00 secondary. Pretty sure!
I reused the original jets. They came out clean (not stripped).
Thinking of putting in the 1.36/1.80 somethings from earlier 40's?
Cool. That's the way I went, too. Great learning experience (...still...).
OK. So the line of thinking is that by reducing the size of the main jets, it will lower the hydrocarbons you are seeing in the emissions report.
Then the 'cause and effect' in this thinking is something like: smaller jet sizes...results in leaner combustion conditions...reduced hydrocarbons... (which would mean that you attribute the high HC's to a 'rich' condition in the cylinders).
So the question you might looking to answer (either through savvy MUD guys or informative MUD threads that already addressed these types of problems, ie 'emissions' threads) is whether or not high HCs are caused by 'rich' or 'lean' conditions...
I know that doesn't answer the question, but just thinking out loud here...
I think I just thought of a simple, valid test you could run to see if you are OK having set the valves at 7* BTDC instead of TDC.
Advance the flywheel so that the 7* BTDC bb is aligned with the alignment mark when the 1st cylinder is on compression stroke (so, the rotor under the dizzy cap is almost pointing to the lead for the #1 ignition wire).
Try to spin the connecting rods for both the intake and exhaust valves on the #1 cylinder between your thumb and index finger. Do they both spin freely?
Now advance the flywheel so that the TDC line is aligned with the alignment mark when the 1st cylinder is on compression stroke (so, the rotor under the dizzy cap is pointing to the lead for the #1 ignition wire).
And try again to spin the connecting rods for both the intake and exhaust valves on the #1 cylinder between your thumb and index finger. Do they both spin freely?
In addition to seeing if the rods spin freely under both conditions, you could also check the valve gap of both the intake and exhaust with your feeler gauge under both conditions. If all these measurements on the #1 cylinder give you the same readings under the two conditions, then you might be OK (ultimately it is your judgement call) in assuming that 7* of crank advance is not enough to put the cam lobe in a position where it is moving a valve.
Well.. update? 
- Thread starter
- #68
Alright Bro!
Initial upgrades/downgrades (ie: de-smog in Utah)
-timing 9* BTDC (4450 elevation)
-new wires, coil, plugs (Parts store)
-Desmog following the guides on MUD
-Manifold gasket (cruiser outfitters)
*This fixed the huge vacuum leak
-Carb rebuild kit (cruiser outfitters)
Initially it ran better when the #6 plug was pulled. Problem was solved when the manifold gasket was replaced.
Next was the de-smog. Seemed to run well so i took it to get the emissions done. It failed miserably here are the numbers in order. (Utah requires the Air Injection and a CAT for the 1987 fj-60)
*Note i had removed the Air Injection
Below are the tests in the order of testing.
1st test- the timing was set @ 7* BTDC at most maybe even less because of idle
2nd test- Notice it got better in some places and worse in others...
3rd test- was thrown away by the testing center Sorry! but very similar to the 2nd test
4th test- Here is where it gets good! I went to Kurts (cruiser outfitters) picked up some jets. (1.14 for the primary) (1.47 secondary) About 10-20% smaller than original, 3 gallons of gas in the tank on 1/4 gal of denatured alcohol, turned idle up to 900 and BAM! it worked. the testing center did not see the pulley in place of the Pump
. I did not have much power and sputtered a bit, but made it fine. Please do this at your discretion.
Thank you to the MUD members for the help and Kurt.
I hope this helps someone!
Initial upgrades/downgrades (ie: de-smog in Utah)
-timing 9* BTDC (4450 elevation)
-new wires, coil, plugs (Parts store)
-Desmog following the guides on MUD
-Manifold gasket (cruiser outfitters)
*This fixed the huge vacuum leak
-Carb rebuild kit (cruiser outfitters)
Initially it ran better when the #6 plug was pulled. Problem was solved when the manifold gasket was replaced.
Next was the de-smog. Seemed to run well so i took it to get the emissions done. It failed miserably here are the numbers in order. (Utah requires the Air Injection and a CAT for the 1987 fj-60)
*Note i had removed the Air Injection
Below are the tests in the order of testing.
1st test- the timing was set @ 7* BTDC at most maybe even less because of idle
2nd test- Notice it got better in some places and worse in others...
3rd test- was thrown away by the testing center Sorry! but very similar to the 2nd test
4th test- Here is where it gets good! I went to Kurts (cruiser outfitters) picked up some jets. (1.14 for the primary) (1.47 secondary) About 10-20% smaller than original, 3 gallons of gas in the tank on 1/4 gal of denatured alcohol, turned idle up to 900 and BAM! it worked. the testing center did not see the pulley in place of the Pump
. I did not have much power and sputtered a bit, but made it fine. Please do this at your discretion.Thank you to the MUD members for the help and Kurt.
I hope this helps someone!
Atta boy. Now about my jets
gregnash
Anal Retentive Analyst
No more PM, it is called Conversations now.
Glad you got it to pass, how crazy is it that you were able to get it to pass emissions with it being desmogged. LOL
Glad you got it to pass, how crazy is it that you were able to get it to pass emissions with it being desmogged. LOL
