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3406B Governor problems at low idle

14K views 19 replies 7 participants last post by  turbo8781 
#1 ·
I have a 4MG that has always had no power at an idle, or what I call "load starting power".
Almost like the gov is not sensing the load when you let the clutch out. If you don't drive it like a toyota you'll kill it every time even in 1st and that with 4.33 gears.
Its always started hard unless you tap the throttle befor you crank. I can't help but think that the two are related.
The gov has been rebiult and I raised the idle to 750 rpm and it didn't change a thing.
Its realy starting to bug me now because this job that I'm on now we have to stop and then take off loaded on 15% grade.

Any help would be greatfull.
 
#2 ·
I would say the race where the governor weights ride has worn holes in it....not letting the weights operate correctly. Also worn throttle shaft in housing possible. Any number of things...have to pull it apart and find the trouble. AFRC another possibility. The bore could be worn in the AFRC not letting the piston move freely.
 
#5 ·
Thanks for the reply Sledman. The gov section has been gon thru twice in the last couple months onec by me, and the problem didn't go away. So I thaught maybe I missed something so i took it to the cat stealer and let them go thru it and all they did was say everything looked good they also put all my fuel settings back to stock (without asking) and charged me for it, and when I raised holy hell about it they siad they would never let a truck leave there shop turned up that high and if you don't like it don't come back.

Now back to the point, isn't it the "wavy washers" that have a lot to do with idle?.
It seems like I read something about adding an extra wavy washer in one of Tony's posts but I can't remember.
 
#7 ·
I would test the power and grounds to the shut down solinoid, back to the battery, moving the wiring around. Also check it for travel. The timming advance, I would also remove that cheaking that the Quad rings are intact, and it is operating properly. Just a thought!
 
#9 ·
I believe if timing was not operating enough to cause slow rev up, he would have skipping and white/grey smoke. May be wrong though....
 
#8 ·
It might not be called this but isn't there an idle buffer screw?? the other thought that goes thru my head is maybe the jake screw is too tight and is taking the lowside of the governor out of the picture(not sure I worded that right either)
 
#10 ·
Just had another thought , since it is relativly easy pull the shut off solinoid and try it with out it, shouldn't be the problem but it is an easy test :popcorn
 
#11 ·
As the problem is only at low idle/ torq, it's not pushing the weights in far enuf. Pull it back apart (again~ sorry), make sure it has the purple striped 8M9141 spring and add the extra 2P9556 washer, pull the rack screw head off and polish the shaft with ScotchBrite, take a cut-off wheel and grind a bunch of slits in the front face of it so it doesn't hydro-lock against the bulk head collar, and re-assemble. Done deal ;)
 
#12 ·
The timming advace does idle different if not working, that is why you get a surge when it starts. But I was thinking more towards the quad rings on the nose going into the cam leaking enough oil to have the govenor lose its reaction ability.
 
#14 ·
As the problem is only at low idle/ torq, it's not pushing the weights in far enuf. Pull it back apart (again~ sorry), make sure it has the purple striped 8M9141 spring and add the extra 2P9556 washer, pull the rack screw head off and polish the shaft with ScotchBrite, take a cut-off wheel and grind a bunch of slits in the front face of it so it doesn't hydro-lock against the bulk head collar, and re-assemble. Done deal ;)
80% of mechanicals require this method for instant start do to this part^^^. it unlocks the "nail head" from the "rack screw collar". Same prob. Without mashing the pedal, it has to build oil pressure and pull the servo and rack out to start up. :thumbsup
 
#16 ·
Thanks Tony, that was more so the answer I was looking for.
Is the 2p9556 the flat washer or is it the wavy washer/spring
and do I need to add another flat washer in between the new wavy washer.

I gues what Im asking is what is the order/configuration of the wavys and flat washers because the cat book already calls for 2 wavys ?.

thanks
 
#18 ·
Cat does'nt make bigger B&P's.....aftermarket does I have heard.
 
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