HJ61 Possible sensitive throttle fix

[Ivy4x4]

Hi all,

OK, I have done a little searching here and found that a lot of people are bothered by the sensitive throttle on the 12HT. I didn't think it was so bad, sure a little on the responsive side until I took it off road..... Man...... surge... bounce....more....less, I couldn't keep it constant unless I used the throttle which was OK in this situation but won't be in all situations.

I've seen people suggesting to make sure there's two springs in the IP, check, upgrade spring strength..... Hmmm maybe as a last resort as long driving is planned for this rig. I've also seen people suggesting the addition of a shock at the accelerator.... another possible option.

What I was thinking was........ and I'm floating out there for your experienced opinions is modifying the linkage at the IP and adding a spring of the right tension and size to move the IP linkage. So what the spring would do is absorb some of the travel initially by stretching and then moving the IP fuel control. The best way to describe it is what you'd see on a briggs and stratton engine on a lawn mower. Hope i've explained it clearly. The only thing that I could see to be a problem is that the spring will eventually stretch and become useless.

Let me know of you thoughts/concerns/trials/or whatever else I've overlooked.

Ivan

 

[blis]

IMHO the problem lies in the flyweight assembly found inside the governor, that tends to loose tension during decades eventually leading to jumpy throttle... Posible fix for that is tension up the flyweight thing, but that requires at the very least the removal of governor which is something most people dont feel comfortable doing....

 

[prado t]

On our HJ 61 , I find that if your foot is in it , The gas pedal stiffens up a bit.

It can get a bit squirmy on the lower rev side of the pedal especially going down a real bumpy road at low revs and shifting .
It is a complex set-up and I also believe that governor fly-weights can add to the mashing .


I did a non sketchy throttle repair on the BJ 74 . It is a simple set-up compared to the HJ 61.

 

[HJ61 12HT]

My HJ61 has an extra spring on the linkage, and the standard spring is inside a piece of rubber tube (like large fuel line). The tubing adds some friction round the sides of the spring, seems to work quite well.

 

[Ivy4x4]

I'm going to give the extra spring a try. Thanks for your input fellas.

 

[wongtsenhin]

My HJ61 has an extra spring on the

Me too! Extra spring

 

[crushers]

well, when i had the 13BT i learned to push my foot against the footwall side and pivot my foot. i had very little sensitive throttle issue driving that way ..

my permanent cure was sell the 13BT and not to own a DI Toyota diesel

but

the common fix is a double spring set up ...

 

[dousty]

Instead of putting extra or heavier springs on the linkage, try a spring on the pedal. That way you won't increase the load on your throttle cable.

It improved my manual wagon alot!

 

[Ivy4x4]

Instead of putting extra or heavier springs on the linkage, try a spring on the pedal. That way you won't increase the load on your throttle cable.

It improved my manual wagon alot!

Thanks, It was going to go upfront but that sounds like a much better idea.

 

[alfchv]

so.... any good news about this issue repair?..any feedback about your modifications?...

 

[Ivy4x4]

I'm running a slightly heavier spring with much improved results on road, off road is still a little touchy but I guess that not everything can be perfect.

 

[alfchv]

do you guys think, that two brand new OEM springs could solve the problem?..

or would the hj61's brand new had that issue?...

 

[blis]

do you guys think, that two brand new OEM springs could solve the problem?..

or would the hj61's brand new had that issue?...

I doubt, since the problem doesnt originate from the springs... It's mainly caused by governer in the IP. Also excess backslash in differentials makes the problem even more obvious...

 

[alfchv]

I doubt, since the problem doesnt originate from the springs... It's mainly caused by governer in the IP. Also excess backslash in differentials makes the problem even more obvious...

and how dificoult would it be to solve the backlash issue?...

is it caused by ring and pinion weare?....

 

[blis]

and how dificoult would it be to solve the backlash issue?...

is it caused by ring and pinion weare?....

It depends on how worn out the pinion axle's bearings are... On mine I snugged up the pinion a bit and it helped a ton with the sensitive throttle/jumpy car problem...

All you need to do is to remove drive shaft from the differential, open up the lock plate and snug up the lock nut on pinion after which you just put everything back in place... Just be careful not to tighten it too much (old bearings might give up)...

 

[alfchv]

It depends on how worn out the pinion axle's bearings are... On mine I snugged up the pinion a bit and it helped a ton with the sensitive throttle/jumpy car problem...

All you need to do is to remove drive shaft from the differential, open up the lock plate and snug up the lock nut on pinion after which you just put everything back in place... Just be careful not to tighten it too much (old bearings might give up)...

thanks a lot....

i'll try the springs tomorrow, then bring some feedback, after that i'll take the toy to the mechanich and give a try to the lock nut and bearing...

 

[60 mad]

hj61 possible throttle fix

Can anyone put some photos up on what springs were replaced and where you got them from. Thanks

 

[crushers]

the sensitive throttle issue is a Toyota direct injection concern, it happens with the 13BT and the 12HT, seems the worst with the 12HT manual tranny setup.
the automatics absorb most of the issue so those with the autos seldom complain at all.

stiffer springs definately help the manual guys.

 

[maat]

Can anyone put some photos up on what springs were replaced and where you got them from. Thanks

x2.

 

[HJ61 12HT]

x2.

Can anyone put some photos up on what springs were replaced and where you got them from. Thanks

Pull the existing spring off, take it to the spring shop and get one slightly stronger, get some fuel line to add friction round sides of spring, slip it on there and see how it goes...
It should make it a little better!

You can see ive got two springs, one inside tubing.