New King Springs - AHC issue - ECU reset?

[suprarx7nut]

I'd hit it with a spray bottle of water and a plastic bristle brush. Clean it up real good. See if that frees it up. I would not use a tool if you can avoid it. I've ruined far more plugs than I've freed up with tools.

If you have to, maybe a flat blade screw driver to press on the tab.

 

[Clunky]

I've replaced the fluid and I installed a new rear sensor today. The fluid change maybe improved the ride slightly, but I detected no change with the new sensor and the ride is still not close to acceptable.

I'm thinking about giving up and reinstalling my old AHC springs (installed 2016 and have about 60K miles on them). The ride wasn't that bad, I was just hoping to reduce body roll in turns. It's possible that I'm just not carrying enough weight for the King Springs.

 

[suprarx7nut]

I've replaced the fluid and I installed a new rear sensor today. The fluid change maybe improved the ride slightly, but I detected no change with the new sensor and the ride is still not close to acceptable.

I'm thinking about giving up and reinstalling my old AHC springs (installed 2016 and have about 60K miles on them). The ride wasn't that bad, I was just hoping to reduce body roll in turns. It's possible that I'm just not carrying enough weight for the King Springs.

Did you ever get a good summary of the data list from Techstream or otherwise?

The spring change shouldn't change comfort that dramatically. I changed mine before adding weight. Barely noticeable difference in comfort. I suspect something else may be going on for you.

Is body roll reduced significantly in sport mode?

 

[Moridinbg]

I replaced mine with King and I had no significant change in comfort (at least in the front, almost never been passenger in the rear in my car lol). I do not have much more weight than stock most of the time. How is your ride height front & rear? Pressures?

 

[Clunky]

After years of being on "team AHC", I'm coming around to the idea that AHC is probably not for me. The care and feeding of the system is too time consuming and there are too many examples of diligent people going through frustration and $$$ as they unsuccessfully chase issues with their AHC system. For the first time I find myself wishing I had gone to a conventional suspension before dumping more time and $ into refreshing my AHC.

My initial impression of the AHC advice threads was that cross leveling, adjusting torsion bars, changing the fluid and replacing the globes would set me up for long term success. After digging deeper, I noticed that people have potential issues with a lot of other items:

-Height control sensors
-Pressure sensors
-Accumulator
-Pump
-Damping force control actuators (part # anyone?)
-ECU
-Clogged lines

It's very likely that I'm missing some additional items that can eventually turn into problems.

I haven't made a final decision, but I'm heavily leaning towards going for a conventional suspension.

 

[Clunky]

I threw in the towel on my King Springs and reinstalled my old AHC springs. The ride is back to comfortable - no more pogo stick! I'll continue to pursue diagnostics of my system, but I believe I'm not carrying enough weight to offset the spring rate of the Kings.

 

[ClassyJalopy]

I threw in the towel on my King Springs and reinstalled my old AHC springs. The ride is back to comfortable - no more pogo stick! I'll continue to pursue diagnostics of my system, but I believe I'm not carrying enough weight to offset the spring rate of the Kings.

That makes sense. Would you consider selling the Kings to me? I am running LC springs and they are bouncing like crazy in the rear.

 

[Clunky]

That makes sense. Would you consider selling the Kings to me? I am running LC springs and they are bouncing like crazy in the rear.

PM Sent

 

[suprarx7nut]

After years of being on "team AHC", I'm coming around to the idea that AHC is probably not for me. The care and feeding of the system is too time consuming and there are too many examples of diligent people going through frustration and $$$ as they unsuccessfully chase issues with their AHC system. For the first time I find myself wishing I had gone to a conventional suspension before dumping more time and $ into refreshing my AHC.

My initial impression of the AHC advice threads was that cross leveling, adjusting torsion bars, changing the fluid and replacing the globes would set me up for long term success. After digging deeper, I noticed that people have potential issues with a lot of other items:

-Height control sensors
-Pressure sensors
-Accumulator
-Pump
-Damping force control actuators (part # anyone?)
-ECU
-Clogged lines

It's very likely that I'm missing some additional items that can eventually turn into problems.

I haven't made a final decision, but I'm heavily leaning towards going for a conventional suspension.

I'm glad you got it sorted out! Weird that King made your ride that different. That's typically not the case. Maybe your butt dyno is better tuned than the average joe!

I think the list you have there of problems is a bit overstated.

Height control sensors go bad, sure. That's a wear sensor and at higher mileages they will start to degrade. Easy fix, though.
Pressure sensor: Can't recall ever hearing of that failing. If it's been mentioned, it's extremely rare.
Accumulator: The height accumulator? Very rare failure.
Pump: They can clog up with gel and go weak, but relatively rare. $250 and pretty DIY friendly replacement.
Actuator: Very rare failure. Part numbers below. Readily available used.
ECU: Extremely rare failure and used ones are basically free.
Clogged lines: Clogged with what? Never heard of that. Very rare, if it's been documented anywhere. I've seen many people fail to bleed the lines and think that something is blocking the lines.

A while back I cataloged AHC failure threads from mud and ClubLexus. Might still have that database somewhere, but it was a bit ridiculous with mis-diagnosis. Almost all the weird failures ended up being something simple. IE Shop replaces all 4 shocks, pressure sensor, actuators, problem still persists... then they replace the globes and the ride is back to normal - duh. Or the pump was replaced and still won't raise. Turns out system wasn't bled enough and was just full of air from a bad flush or burst globe, etc...

 

[IndroCruise]

I'm glad you got it sorted out! Weird that King made your ride that different. That's typically not the case. Maybe your butt dyno is better tuned than the average joe!

I think the list you have there of problems is a bit overstated.

Height control sensors go bad, sure. That's a wear sensor and at higher mileages they will start to degrade. Easy fix, though.
Pressure sensor: Can't recall ever hearing of that failing. If it's been mentioned, it's extremely rare.
Accumulator: The height accumulator? Very rare failure.
Pump: They can clog up with gel and go weak, but relatively rare. $250 and pretty DIY friendly replacement.
Actuator: Very rare failure. Part numbers below. Readily available used.
ECU: Extremely rare failure and used ones are basically free.
Clogged lines: Clogged with what? Never heard of that. Very rare, if it's been documented anywhere. I've seen many people fail to bleed the lines and think that something is blocking the lines.

A while back I cataloged AHC failure threads from mud and ClubLexus. Might still have that database somewhere, but it was a bit ridiculous with mis-diagnosis. Almost all the weird failures ended up being something simple. IE Shop replaces all 4 shocks, pressure sensor, actuators, problem still persists... then they replace the globes and the ride is back to normal - duh. Or the pump was replaced and still won't raise. Turns out system wasn't bled enough and was just full of air from a bad flush or burst globe, etc...

View attachment 2732339

Great summary!!

 

[trdcorolla]

I threw in the towel on my King Springs and reinstalled my old AHC springs. The ride is back to comfortable - no more pogo stick! I'll continue to pursue diagnostics of my system, but I believe I'm not carrying enough weight to offset the spring rate of the Kings.

Is your build info in your signature still correct?

BIO step sliders - BIO Front Skid - BIO Rear

That looks like more than enough weight to offset the higher King spring rate. I'm assuming your purchased KTRS-79 coils?

 

[ktmracer01]

Very interesting to see the King springs had so much of an impact on the ride quality...? @suprarx7nut you're absolutely right bout everything you mentioned. I just spent the last 4 weekends helping someone diagnose and fix their AHC system. It only took that long because of the time ordering parts and just making sure we were troubleshooting everything correctly. Plus bleeding the system 1000x to make sure there wasn't any air in it before jumping to conclusions on parts.

From everything @Clunky mentioned, I would suspect the spring rate on the king springs was intended for a much heavier load. Did you ever share a part number for the rear springs that you bought?

I'm running kings and coil spacers without any of the weight I'm expecting to see with a rear bumper and all recovery gear, and haven't had the issue you mentioned.

 

[Clunky]

Is your build info in your signature still correct?

BIO step sliders - BIO Front Skid - BIO Rear

That looks like more than enough weight to offset the higher King spring rate. I'm assuming your purchased KTRS-79 coils?

Yes, bio info is correct. I don't have swing outs on my rear bumper though.

Yes, KTRS-79.

 

[Clunky]

Pump: They can clog up with gel and go weak, but relatively rare. $250 and pretty DIY friendly replacement.

Where do you get a pump for $250? It looks like $2600 on Lexus Parts Now and $1250 on Impex.

 

[ktmracer01]

Very surprising. Those are the same springs I have in mine. Sorry to hear it didn't work out for you.

 

[suprarx7nut]

Where do you get a pump for $250? It looks like $2600 on Lexus Parts Now and $1250 on Impex.

Here's the motor for <$180: MOTOR, SKID CONTROL 8826460010 | Toyota Parts | PartSouq - https://partsouq.com/en/search/all?q=88264-60010
And the Pump for <$170: PUMP SUB-ASSY, HEIGHT CONTROL 4890160010 | Toyota Parts | PartSouq - https://partsouq.com/en/search/all?q=48901-60010

Pricing is a little higher stateside and fluctuates on a regular basis, but it's still $300-350.

Normally the pump is all that goes bad, but I included the motor since that could theoretically wear out too.

Your $1250-2600 estimate is a good example of how AHC gets it's mis-applied bad rap. That's a large assembly with way more than what you need unless the entire assembly burned in an engine fire or something crazy. If a shop sees a bad pump, they're probably quoting the $2600+ part and completely bypassing the actual failed component which is readily available for literally less than 10% of the assembly cost.

 

[SHIfTHEAD]

So I'm reading all that I can find, am I correct in understanding that these Kind springs are too stiff for the stock LX470? I want the compliant ride I have now, but if after market springs aren't going to work I'll foot the $500 for Lexus springs. I think $500 every 15 years is acceptable to me.

Edit: Now that I am actually searching for OEM stuff, it appears I can buy them out of UAE for about $300 for the pair. When looking at Partsouq, for example, it lists two part numbers for the RH and LH, but the LH is no available. Other vendors list the springs as both RH & LH. Presumably, they would work either side, but the LH spring would have been slightly stiffer. As I am also going to run airbags (for when I have my motorcycle on the hitch hauler) this difference should be minimal at best I would assume. Thoughts? (Sorry for the hijack, but there are some good experts already here!)

 

[IndroCruise]

So I'm reading all that I can find, am I correct in understanding that these Kind springs are too stiff for the stock LX470? I want the compliant ride I have now, but if after market springs aren't going to work I'll foot the $500 for Lexus springs. I think $500 every 15 years is acceptable to me.

Edit: Now that I am actually searching for OEM stuff, it appears I can buy them out of UAE for about $300 for the pair. When looking at Partsouq, for example, it lists two part numbers for the RH and LH, but the LH is no available. Other vendors list the springs as both RH & LH. Presumably, they would work either side, but the LH spring would have been slightly stiffer. As I am also going to run airbags (for when I have my motorcycle on the hitch hauler) this difference should be minimal at best I would assume. Thoughts? (Sorry for the hijack, but there are some good experts already here!)

Suggest that if you want “as designed” comfort (meaning best damping for stock vehicle), replace with the “as designed” OEM springs. If you want more load capability, replace with KTRS-79 springs with stiffer spring rate around 130 pounds per inch of deflection and possibly leading to some damping compromise when unloaded, compared with around 90 pounds per inch with OEM springs. If you want “as designed” comfort with some load flexibility, replace with “as designed” OEM springs and consider adding airbags inside springs at the same time or later. Airbags can be held at around 5psi to hold shape when additional load capability is not required, with negligible comfort effects. Airbag pressure can then be added only when supplementary load capability is required.

 

[SHIfTHEAD]

Suggest that if you want “as designed” comfort (meaning best damping for stock vehicle), replace with the “as designed” OEM springs. If you want more load capability, replace with KTRS-79 springs with stiffer spring rate around 130 pounds per inch of deflection and possibly leading to some damping compromise when unloaded, compared with around 90 pounds per inch with OEM springs. If you want “as designed” comfort with some load flexibility, replace with “as designed” OEM springs and consider adding airbags inside springs at the same time or later. Airbags can be held at around 5psi to hold shape when additional load capability is not required, with negligible comfort effects. Airbag pressure can then be added only when supplementary load capability is required.

Actually the last option is exactly what I've got planned, so I'm glad you mentioned it. The airbags are sitting on my work bench waiting on the springs. So cool, I know which way to go now. Thanks dude!

 

[suprarx7nut]

Actually the last option is exactly what I've got planned, so I'm glad you mentioned it. The airbags are sitting on my work bench waiting on the springs. So cool, I know which way to go now. Thanks dude!

Another option if you find yourself routinely having to mess with the airbags is to add 30mm spacers to your old and tired OEM springs. That tends to correct pressures better than new OEM springs and maintains a spring rate very close to OEM.