1HD-T idle shake

[Martin White]

Hmmm. That does sound like something that would probably happen to me. I'm still not convinced that anyone local here knows how to deal with this problem, and from what I've heard, there are quite a few trucks with rough idles like mine that are probably in the same boat. The only "solution" I've heard from our local Denso rebuilder is to rebuild the whole pump including the ACSD and thermo wax. So I'm really stuck.

Also with the blanking plate mod we need some more details. It seems to me that if this system can change the pump timing and richness of the fuel mix, that this may also explain my continued sub par fuel consumption which is a little better, but the truck is still consuming about 13.5 l / 100 km in mixed all around driving, not what it should be. I've not been happy with any of the explanations I've heard as to why, since all the rest of my truck is in perfect shape. I think this system may have something to do with it.

I'm thinking of actually calling that international repair shop's number you gave me and seeing what they suggest. Otherwise, as I said, I'm stuck. The truck is still at Ateb having other things done so I have some time.

Thanks again for continuing to pay attention to this thread.

 

[crushers]

Good point but I dont know.
Some of the guys on Outer limits swear a pusher pump rejuvenates the pump pressure on HZJ75
Im off to a diesel injection shop in 15 mins so Ill add that to my questions.
I have a spare pump I got cheap and I am having it bench tested

i have tried a pusher pump on the 2LT and it does make a difference... easier starts and more "seat of the pants" performance. (i have not tried it on the HZ though or the HDT)

 

[Martin White]

Wayne, I sent you a private message on this topic because I hadn't seen you on this thread, but now that you're here...have you dealt with this issue with your trucks? What do you suggest be done? My truck has the EXACT symptoms consistent with the thermowax / ACSD problem. But unfortunately there is little help in B.C., so far. I talked to Allied Holmes, and they said they just rebuild the whole thing, no interest in a blanking plate mod. Ateb doesn't seem to want to talk about this problem either. Suggestions? (besides patience, I know some things are still in the works).

 

[crushers]

Martin,
i have not had this issue rear it's ugly head so no advice can i give... sorry.

 

[roscoFJ73]

Martin I cornered he owner of the injection shop I go to and he confirmed that you remove the thermowax as an assembly,remove the lever the thermowax pushes on ,block off the coolant hoses and put the blanking plate on.
No internal mods to be done.

There is no part number for a blanking plate. Toyota says it probably comes with the complete pump hou$ing.
So they may need to made up which is simple enough.

In regards to the piece that can break off another shop says it has to rattle full time before it happens. Usually they rattle during warm up and it goes away.

Another thing about when a pump is worn and needs a complete rebuild is that it is at high speed and fully warmed up when it loses pressure ,not at idle speed.
If your pump has no leaks or seepage it should be possible to bench test it to see if it can hold pressure.
Its overkill to just rebuild a pump without testing it
This is what I had done to my spare pump today. It needed a seal kit and a clean up to get rid of the dried 4 yo diesel but it tested good for pressure.

 

[Martin White]

Understood. That's very helpful. That leaves one more question. You said "in regards to the piece that can break off". Are you referring to the cold start lever or is this something else? If I'm reading this right, I'm assuming the lever is the cold start lever. If this is correct, then once the mod is done, that piece is gone anyway and problem solved? Just want to make sure I understand this. If there is another lever or some other part that can break off, please explain. Thanks again for your help.

 

[roscoFJ73]

Understood. That's very helpful. That leaves one more question. You said "in regards to the piece that can break off". Are you referring to the cold start lever or is this something else? If I'm reading this right, I'm assuming the lever is the cold start lever. If this is correct, then once the mod is done, that piece is gone anyway and problem solved? Just want to make sure I understand this. If there is another lever or some other part that can break off, please explain. Thanks again for your help.

I havent tinkered with the 1HD T pump and I can only trust what 2 shops have told me.
I really dont know exactly what happens inside except that both shops have said the same thing. There is no internal work to be done.

 

[jcolvin]

Martin I cornered he owner of the injection shop I go to and he confirmed that you remove the thermowax as an assembly,remove the lever the thermowax pushes on ,block off the coolant hoses and put the blanking plate on.
No internal mods to be done.

There is no part number for a blanking plate. Toyota says it probably comes with the complete pump hou$ing.
So they may need to made up which is simple enough.

Looking at my pump it looks like the thermowax assembly should just pull off when you remove the two retaining bolts. I'm not sure exactly what the bit is that breaks off, but I assume it must be attached to the assembly on the inside. I'm assuming it can be done with the pump attached, I guess one of us will have to bite the bullet, pull it and see.

I'm pretty sure I see a part number for the blanking plate. Looking at the exploded diagram, there is a blanking plate on the engine side of the fuel pump, part number 22612B. I will check with ENS Toyota to see if they have it.

 

[beanz2]

I somehow don't think this has to do with the ACSD. Mine was bad and I just replaced it (see separate thread) but the symptoms were completely different.

Dave

 

[jcolvin]

I somehow don't think this has to do with the ACSD. Mine was bad and I just replaced it (see separate thread) but the symptoms were completely different.

Dave

I think yours went a different sort of bad.

They go bad two different ways. The moving arm can get loose (which is probably what was causing your clicking noise), and if it gets bad enough the inside piece can fall into the pump causing all sorts of problems.

The other way they go bad is that the wax pellet plunger sticks, screwing up your idle.

The latter is the cause of this problem, in my experience.

 

[tcurrie]

Truck has gone to Ateb today for a long list of things I've wanted done for some time. I mentioned this idle shake before but it's come back. Sometimes, not always, after a run on the highway, when I come back to stop and go traffic, the idle will drop and the truck shakes violently but doesn't stall.

It will smooth out if I idle it up a bit. The truck has recently serviced injectors and no other known issues. I talked to Ken at Ateb today about this and he mentioned that the injectors on the 1HDT are quite hard to set up properly and that it may have something to do with the fuel pump. It doesn't seem to matter if the a/c is running or not. Anyone have any thoughts on this or a similar issue? When I say rough, I mean the whole truck is literally shaking. As far as I know there is nothing else wrong with the truck. It has been very well maintained.

Finally! Someone else with the same problem. Im glad I stumbled on this thread. Mine has been doing the exact thing since the day I picked it up 3 months ago. Not all the time but very often. It is made worse by the A/C turned on so I dont use it. I find on cool mornings it runs great and silky smooth at idle but later in the day its frustrating having to step on both peddles at a light to stop it from shaking. I also have really poor power and black smoke when it acts up. Is your power effected at all?

Maybe we can get to the bottom of this with some help.

 

[sandcruiser]

Rosco, any chance you could scan those backing plates and post it up?
Or just measure the distance/size of of the holes, as well as the overall size?

I can get a cover built here, cheaply, but don't want to tear into the vehicle first if it can be avoided.

Otherwise, has anyone had luck with toyota block-offs? I'm keen to do this mod as this truck is very very unlikely to see any temps below freezing, ever, so why have an extra part to break? Then I can also use the coolant lines that are there for my SVO filter.

 

[gilghana]

Pusher pumps

Over the last 13 years the company I work for has run a fleet of 75s, 80s, 105s all 1HZ engines. Fully agree with the comments on the lifespan. Once the pump is worn then they can go downhill quick - will start fine when cold, but a nightmare when hot... We found that putting electric pusher pumps helps quite a lot and delays the inevitable! Haven't tried it on a good performing pump though.
Oh and my first one ('96 75 series) is still used as a local runabout for the electricians - it only saw asphalt when we bought it. The speedo packed in years ago, but it will probably have about 750,000kms on it. And the pump is on the way out for probably the 6th time. 12 years on African roads - bloody tough trucks 'eh.
Gil

 

[roscoFJ73]

Rosco, any chance you could scan those backing plates and post it up?
Or just measure the distance/size of of the holes, as well as the overall size?

I can get a cover built here, cheaply, but don't want to tear into the vehicle first if it can be avoided.

Otherwise, has anyone had luck with toyota block-offs? I'm keen to do this mod as this truck is very very unlikely to see any temps below freezing, ever, so why have an extra part to break? Then I can also use the coolant lines that are there for my SVO filter.

A lot of oher plates off Bosch VE pumps are the same. Im sure someone used a VW diesel plate.
I sent all my spare plates away

 

[sandcruiser]

can someone out there take a few photos of their IP?

I don't know which bits are original, which were added/removed by the PO and what does/doesn't belong.

Back on topic: spent some time fiddling with the ACSD yesterday. First observation is that at 85*F ambient temperature, it only takes a few seconds before the ACSD moves. 2nd observation: it looks like someone has basically disabled it on my IP. When cold, the plunger doesn't touch the arm. When hot, it doesn't touch the arm. Seems like it should touch at some point!

Also- there was a spring mounted into a point that looks like it should have a cable/ferrule, on the same arm linkage that reacts to the ACSD. I thought maybe it was where a hand throttle would hook in-- but it appears that the action of the cable would be to *reduce* rpms, not advance. Anyone have said cable? What does it do?

Thanks

 

[Tapage]

mine ..

 

[Hovenator]

Resserection

Curious about the out-come here. Has anyone pulled this "thing-a-magig" out and blanked it off?

From my paranoid brain... what exactly does this rattle sound like. My truck has only been in my possession for 4 days so there are many sounds I don't know!

 

[spartacus]

mine ..

my HDJ81 seems to do the same symptoms...
where is the ACSD located from the picture of the IP?

cheers

 

[sandcruiser]

David,
the acsd is at the lower left corner. Right where the wire loom almost touches the arm that is connected to the spring

sorry, confusing.

 

[simonliew]

Hi,
fuel was leaking from the ACSD shaft last year,so l remove the ACSD and made my own blanking plate out of 1/8" steel and use the original Oring and screws,l don't have the fast idle when cold now,l like it that way because in Winnipeg's winter,the fast idle can go on for 15 minutes and really stingky exhaust at hi idle.
Simon