ACSD Removal 1HD-T (1 Viewer)

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Thanks for the update @jules781 ! Any pointers, tidbits, or gotchas that you can share about the removal? Did you remove the spring first to gain access to the 5mm hex key bolts? How much diesel came out? And what about the coolant lines...how did you handle that? Any info you can share would be great! Congrats on the removal!
 
this was done on mine before I got it at some point (2012) and it has always started on the first 1/4 of a turn ever since. coolant hoses are looped (shoddily) and I have since thought about capping the outlets instead of flowing through.

should/would this make any difference to anything? im thinking not.
 
sorry for the late reply, I had to dis assemble it on the car so remove the spring assy first to gain access to the allen keys I put a joiner in the hose and cable tied it out of harms way and fitted the blanking plate. So far so good been alright on colds days little more smokey but once it warms up its fine.
 
Did the remove today and have some diesel knock now. Do you have to do the pump timing after the delete? I think is it over advanced now and the ACSD was holding it to the retarded side but not sure what the starting point should be..
 
I removed mine a few weeks ago and my truck is much quieter. Mine cackled quite a bit before, and I kinda liked it. But it's kinda nice having a quieter rig. I think it affects the timing marginally, but probably not a big deal.
 
It should run at "warm engine" timing all the time with the ACSD removed, it should not result in advanced timing with it removed. The ACSD's purpose is to advance timing when the engine cold only.
 
Nuh left the timing as it was when I fitted the pump. U should not have to change the timing as the acsd is disabled when setting the timing up when fitting the pump.
 
A HUGE shout out to all the Ih8mud folks that gave me helpful tidbits, advice, and pictures. I wanted to return the favor by posting a bunch of photos of my recent (Dec. 9, 2017) removal of the ACSD on my 91 HDJ81 (RHD, 5-speed manual) with the 1-HDT.

In addition to preventing a future, expensive disaster with the ACSD when it would have inevitably sheared off, I removed it recently because I though it was leaking diesel by the ACSD spring. Hindsight being 20/20, I found out after I removed the ACSD that my injection pump is leaking elsewhere, so I will be having the injection pump replaced (exchanged with a rebuilt one) soon :) Go figure. At least I went through the process and can share my experience with others looking to do this as well.

A few tidbits:
* I was able to remove the ACSD without having to remove the ACSD spring (FYI). I had to use a 6 inch long handle 5mm hex key to do the tricky parts. Some of the photos show a red handled 5mm hex key...this is what made it possible for me. You may have to manually engage the ACSD by using a screw driver (the FSM tells you how to do this when setting the timing, FYI), to be able to reach one of the 5mm hex head screws.
* I sprayed all the 5mm hex head screws (5 of them)...2 for the A/C idle up, and 3 for the ACSD itself...with liquid wrench. Luckily I did not have to grind anything off; everything came off without too much trouble.
* I lost about 2 cups of diesel or so...I used a catch basin located below the area, on the ground. You will get diesel all over stuff, it's inevitable.
* I lost very little coolant when replacing the coolant line. I found this method worked the best: The ACSD uses coolant to engage/disengage. The ACSD's coolant lines connect to the engine block in only two places, one upper and one lower (you can trace where they go by following the hose). First, pull the coolant line that attaches to the upper part of the engine block and plug it with your finger (I had someone help me do this!!). As a warning, the old coolant lines were VERY difficult to remove from the engine block...getting a suitable grip on them without ripping/tearing them up is challenging. Second, have your replacement coolant line (and hose clamps already on!!) ready to go. Third, disconnect the bottom engine block coolant line and be ready to fit the new replacement line on. Keep that top port plugged, as this keeps coolant from gushing out. Now that the bottom port is connected to the replacement coolant line, plug in the other end to the upper engine block port and engage the hose clamps.
* I did NOT need to adjust the timing...it runs great (besides the fact that our injection pump is leaking!) and is quieter for sure
* I only pumped the fuel primer pump a few times after I had removed the ACSD and installed the backing plate...it started right up with no issues whatsoever.

Hope this helps!

Below are photos of the process in chronological order...hopefully they help others. Remember, I have a 5-speed manual, so I don't have the automatic kick-down cable or any of that stuff near the injection pump :)





















Thanks y'all!
 
Lol, you were like 24 hours short on posting this for me! I tackled this in my driveway yesterday and had so many questions! Eventually got it done, minus the new coolant line. Great writeup and great pics.
 
So where did you guys source backing plate and o ring. I'm 99% sure now that my noise is coming from acsd. Only does it when cold and goes away when warmed up. Also is the backing plate, o ring and replacement hose all I need to do conversion? Have only had my hdj81 for about a month so still learning. And since it's been almost 3 years since you did this HillCountryTX, how is it running? Never had to advance timing? Any issues since? Would like to just buy a new acsd but not having any luck finding one. TIA
 
So where did you guys source backing plate and o ring. I'm 99% sure now that my noise is coming from acsd. Only does it when cold and goes away when warmed up. Also is the backing plate, o ring and replacement hose all I need to do conversion? Have only had my hdj81 for about a month so still learning. And since it's been almost 3 years since you did this HillCountryTX, how is it running? Never had to advance timing? Any issues since? Would like to just buy a new acsd but not having any luck finding one. TIA


This thread has some info on Denso/Bosch part numbers. Theses guys from AU advertise blanking kits on FB. Diesel, Sunshine Coast, Diesel Power Systems

Ebay is a good source for a new ACSD. Just search "22790-17540" for 92-97, or "22790-17141" for 90-91. Often times they will be out of the 90-91 one, but more will come in.
 
A HUGE shout out to all the Ih8mud folks that gave me helpful tidbits, advice, and pictures. I wanted to return the favor by posting a bunch of photos of my recent (Dec. 9, 2017) removal of the ACSD on my 91 HDJ81 (RHD, 5-speed manual) with the 1-HDT.

In addition to preventing a future, expensive disaster with the ACSD when it would have inevitably sheared off, I removed it recently because I though it was leaking diesel by the ACSD spring. Hindsight being 20/20, I found out after I removed the ACSD that my injection pump is leaking elsewhere, so I will be having the injection pump replaced (exchanged with a rebuilt one) soon :) Go figure. At least I went through the process and can share my experience with others looking to do this as well.

A few tidbits:
* I was able to remove the ACSD without having to remove the ACSD spring (FYI). I had to use a 6 inch long handle 5mm hex key to do the tricky parts. Some of the photos show a red handled 5mm hex key...this is what made it possible for me. You may have to manually engage the ACSD by using a screw driver (the FSM tells you how to do this when setting the timing, FYI), to be able to reach one of the 5mm hex head screws.
* I sprayed all the 5mm hex head screws (5 of them)...2 for the A/C idle up, and 3 for the ACSD itself...with liquid wrench. Luckily I did not have to grind anything off; everything came off without too much trouble.
* I lost about 2 cups of diesel or so...I used a catch basin located below the area, on the ground. You will get diesel all over stuff, it's inevitable.
* I lost very little coolant when replacing the coolant line. I found this method worked the best: The ACSD uses coolant to engage/disengage. The ACSD's coolant lines connect to the engine block in only two places, one upper and one lower (you can trace where they go by following the hose). First, pull the coolant line that attaches to the upper part of the engine block and plug it with your finger (I had someone help me do this!!). As a warning, the old coolant lines were VERY difficult to remove from the engine block...getting a suitable grip on them without ripping/tearing them up is challenging. Second, have your replacement coolant line (and hose clamps already on!!) ready to go. Third, disconnect the bottom engine block coolant line and be ready to fit the new replacement line on. Keep that top port plugged, as this keeps coolant from gushing out. Now that the bottom port is connected to the replacement coolant line, plug in the other end to the upper engine block port and engage the hose clamps.
* I did NOT need to adjust the timing...it runs great (besides the fact that our injection pump is leaking!) and is quieter for sure
* I only pumped the fuel primer pump a few times after I had removed the ACSD and installed the backing plate...it started right up with no issues whatsoever.

Hope this helps!

Below are photos of the process in chronological order...hopefully they help others. Remember, I have a 5-speed manual, so I don't have the automatic kick-down cable or any of that stuff near the injection pump :)





















Thanks y'all!
This was very simple to follow and I was able to knock it out on my 1995 1HDFT. To also try to be helpful myself, I would like to add the size of the bolts are used or 15 mm in length. My 95 also has an additional shift link and is an automatic transmission.

attacking this from the passenger side wheel well was brilliant. The issues I ran into was not knowing how to loop the coolant hoses together. For the time being, I am just going to zip tie the ASCD Out of the way until I figure out how to link the two lines together or replace with a single hose.

I hope this helped.
Denso
Blanking Plate part #096218-0270
O-Ring part#096049-0400
 
This was very simple to follow and I was able to knock it out on my 1995 1HDFT. To also try to be helpful myself, I would like to add the size of the bolts are used or 15 mm in length. My 95 also has an additional shift link and is an automatic transmission.

attacking this from the passenger side wheel well was brilliant. The issues I ran into was not knowing how to loop the coolant hoses together. For the time being, I am just going to zip tie the ASCD Out of the way until I figure out how to link the two lines together or replace with a single hose.

I hope this helped.
Denso
Blanking Plate part #096218-0270
O-Ring part#096049-0400

Use a 5/8 inch barb fitting, with two hose clamps.

Amazon product ASIN B00SB9HJ1A
I cut my line a bit shorter as well once I was happy with how it ran after removal, makes it cleaner. It's all in my build thread.
 
Got a leaky ASCD. Cannot find a plate! Anybody have any leads, ideas, or a plate and o-ring they'd sell?

Norwood, CO
 
7B0CBE3F-EFC8-4875-B4F4-8E98D4BFE30A.jpeg
Got a leaky ASCD. Cannot find a plate! Anybody have any leads, ideas, or a plate and o-ring they'd sell?

Norwood, CO

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