CT26 Wastegate Actuator?

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Feb 2, 2007
Edmonton AB
Hi guys, sorry for the story but this is more for detail and diagnosis help...:popcorn:

Comming home from a camping trip(7hrs away) my rig developed a weird problem about 30 minutes from town. I first noticed it when I went to pass a car and I could barely get over 110km/hr and about 10mins later 100km/hr and progressively got worse as I got into the city and by the time I got to the neighborhoods I could only get up to 60km/hr. During this whole time my boost was all over the place and I noticed that if I took off from a stopped position it would climb to 11PSI and then bleed off and the most it would give me was 4 maybe 5 PSI until I came to another red light or stop sign.

Unfortunately I had no time to pull things apart since it was late and I had to catch a flight at 4am to go back to work and won't be coming home for 28 more days. Fortunately I have a brother thats volunteering to help diagnose the problem while I am away.

Here is what I've had him do so far:

Take off the intake side piping to get access to the Turbo...he noticed a lot of oil in the pipes due to the breather but he checked the oil level and it was good.

He then proceeded to pull off the waste gate actuator air line from the turbine housing and plug it.

He took it for a spin but carefully watched the boost gauge so he wouldn't spool the crap out of it. No loss of boost and he said it was insanely powerful at 15psi....he couldn't help but give it a go. He said the throttle response was fast and stable.

So this leads me to think that the wastegate Actuator is pooched.

He didn't have time grab a bike pump with gauge or anything like that to test the actuator but if the wastegate is staying closed then maybe the actuator is sticking internally?

What do you guys think?

By the way it's for a 1990 1HD-T with 186 000kms

if I bypass my wastegate .. my CT26 can make 20 plus PSI in a blink .. and yes sounds like your wastegate diaphragm or spring .. only way to be sure it's test it ..

What it's weird to me it's that happen suddenly and that's make me doubt about the wastegate ..
Yah my brother said once the actuator was disconnected and he went for a spin, the turbo spooled up fast and clean with crap loads of boost...I believe he burried the boost gauge needle with no effort lol. Said it felt way more powerful than when he was riding with me before I was getting these issues.

I guess when I get home I will have a new Valve set tool waiting for me as well as an injector timing dial set, an Air-Water intercooler kit....and an actuator if I can find one. Gonna give the ol' beasty a good tune up.

Anyone know where I can source an Actuator?

My brother never got the chance to disconnect it from the actuator, however if the Turbo is boosting with the actuator hooked up and the air line disabled that means the wastegate is functioning. When the air line to the actuator is hooked up and he stepped into the gas peddle the turbo would boost up to around 11psi and then immediatly the boost would drop to like 4-5psi. This is why I think the actuator is not moving freely and allowing the waste gate to close to maintain boost. Hope I'm right on this one because I just sourced a new actuator for $50 with shipping. Man are they ever hard to find.
maybe and just maybe the spring inside it's loosing tension .. I¿m guessing here. good luck and let us know what do you found ..
would the spring lose tension that fast though? It ran perfectly till the last leg of the trip. And when you mean spring you mean the one inside the actuator right? I've read a lot about guys shimming the actuator to increase tension on the spring therefore keeping the wastegate closed better and increasing boost at the same time...depending on how much you shim that is.
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Well I guess I'll find out when I get home on the 23rd. I'll let you know what I find out when I get it fixed.

Ok here is an update of this problem. I don't think it was the boost actuator that was causing the problem. It turned out that when I was reinstalling the turbo and exhaust manifold back on I noticed a missing nut on the intake manifold side....the other 11 nuts were spinning freely with just the touch of a finger tip...guess where my boost was going? I changed out the actuator anyway since I had a new one on hand and I tested the old one and it worked but the rod extended at an angle due to wear on the felt/rubber guide in the housing. The new one was nice and true when tested.

Everything buttoned up and ready to start!>....ahhh crap!!! my brother left the door cracked open for 3 weeks...batteries were dead.

Batteries charged and starts like a top... test drive down the highway, like new! yay!
Holy crap I saw this post and had to do a double take, realizing I wrote this one...Sorry Merrick, didn't see your query 6 years ago.

You're timing is horrible! I just threw out my old actuator like a week ago since it's been sitting around and I figured I'd never get around to needing it anymore.

But wait! there's more! My old CT26 detonated and I just might have the newer actuator still attached. I will have a look for you when I get home on the 29th. If you want it you can have it, just as long as I can find it on the old compressor housing. Just pay for postage. If you want a new one, I found mine on the internet by looking up CT26 Boost actuator. Here's a few examples:

This is an aftermarket one that can be adjusted for different boost levels:
Kinugawa Forged Actuator TOYOTA CT26 1HD 1HD-FTE

Ebay search "ct26 boost actuator or controller":
ct26 boost actuator | eBay

OEM style for 1HD-T
Wastegate Actuator Vacuum fit TOYOTA Land Cruiser 4.2 1HDT 1720117010 Turbo | eBay

Good luck!
Look what I found! :grinpimp:


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