Did my turbo die?! (1 Viewer)

[oszkari]

Glad you got the dash light stuff figured out, when it rains it pours eh?

Don't pull your turbo out just yet, you can check shaft play with the inlet hose removed, and by removing the MBC you can check wastegate function and confirm everything's working as intended there. If the turbo check out, then you can move on to checking other things.

No kidding..for the past 12 months I had the feeling that the cruiser really wants to test my affection towards him.

 

[dan1554]

Hmm, based off your description, I think your MBC was venting to atmo. That means that once you hit certain boost, it did not reach the wastegate actuator. So not only was your turbo probably spinning insane RPMs, but you effectively had a hole for all that air to escape from once the MBC opened. Thus the lack of power.

*EDIT*
Now that I think about it, your MBC would have had to have been set below the wastegate pressure for that to happen. I think. Take this theory with a grain of salt. Either way sounds like it was an odd setup.

 

[IanB]

Updates...

I have redone my MBC and after a test run there is a significant improvement. Lot more power and the MBC seems to be doing its job.

My previous MBC was installed using a T in between the turbo compression side and the waste gate actuator. (pic attached). I have removed the T, capped the compression side of the turbo (where the clamp is on the pic) and went directly from the wastage actuator to the mbc output. I T-d the intake manifold air hose for the mbc input.

Did I do it right? I don't really understand how my previous mbc was working with the T there?! How was the mbc controlling the pressure if there was a direct path between the compression side and the wastage ?

Great news, sounds like something was wonky with your old MBC setup.

I don't think the T'd install method is best, the way I have mine set up is I replaced the hose from the outlet to the wastegate with a longer one that I ran up near the airbox, and installed the MBC in-line and then run the hose back down to the wastegate, so the air HAS to pass through the MBC to get to the wastegate. By T-ing that hose, I'm not sure you'll get the exact same effect as there's still a direct route from the compressor outlet to the wastegate...I'm not really sure on the effect of this different install method.

By T-ing into the intake manifold hose you may have more of a delay in the MBC's effect than if it was right on the compressor outlet, but if it works then it works.

 

[oszkari]

Great news, sounds like something was wonky with your old MBC setup.

I don't think the T'd install method is best, the way I have mine set up is I replaced the hose from the outlet to the wastegate with a longer one that I ran up near the airbox, and installed the MBC in-line and then run the hose back down to the wastegate, so the air HAS to pass through the MBC to get to the wastegate. By T-ing that hose, I'm not sure you'll get the exact same effect as there's still a direct route from the compressor outlet to the wastegate...I'm not really sure on the effect of this different install method.

It was installed by a reputable cruiser shop and it was working for years, so I cannot say that it was wrong but I certainly don't understand it.

What I have noticed now is that the boost stays at constant 15 PSI (that's where I set the mbc) while the EGT is building up under load.
If I remember correctly with my old mbc once I reached 17psi (that where it was set) the boost would just drop.

Which one is the expected behaviour?

By T-ing into the intake manifold hose you may have more of a delay in the MBC's effect than if it was right on the compressor outlet, but if it works then it works.

Seems to be working..I might still re do it your way

 

[oszkari]

Can anybody explain what is the purpose of the thingy in the red circle? Currently for me it is not plugged anywhere. I wonder if I missed something.

 

[oszkari]

Hmm, based off your description, I think your MBC was venting to atmo. That means that once you hit certain boost, it did not reach the wastegate actuator. So not only was your turbo probably spinning insane RPMs, but you effectively had a hole for all that air to escape from once the MBC opened. Thus the lack of power.


*EDIT*
Now that I think about it, your MBC would have had to have been set below the wastegate pressure for that to happen. I think. Take this theory with a grain of salt. Either way sounds like it was an odd setup.

My mbc was dialled to the minimum and was still over boosting. Now with the new setup the same mbc is turned two full turns to get to 15psi.

 

[IanB]

Boost should reach your target level, and stay there until engine load is reduced. Gas pedal will continue to add fuel the further you push the pedal down, and EGT's will rise accordingly.

The plugged off nipple on the air filter housing is normal, I'm not sure what other market stuff would have been attached there, probably something for emissions?

 

[oszkari]

Boost should reach your target level, and stay there until engine load is reduced. Gas pedal will continue to add fuel the further you push the pedal down, and EGT's will rise accordingly.

Thanks!

The plugged off nipple on the air filter housing is normal, I'm not sure what other market stuff would have been attached there, probably something for emissions?

My old mbc input was plugged to that nipple.

 

[Locked79]

Can anybody explain what is the purpose of the thingy in the red circle? Currently for me it is not plugged anywhere. I wonder if I missed something.

View attachment 1639823

That nipple and the one on the lid is for an air filter restriction indicator. Basically tell you when the filter is blocked, with a light coming up on the dash.

 

[Locked79]

 

[oszkari]

View attachment 1639882

Is that 1HD-FTE specific or the 1HD-T should have it too?

 

[dan1554]

Is that 1HD-FTE specific or the 1HD-T should have it too?

Not there on my 1hdt (not saying it never was though).

 

[Locked79]

Is that 1HD-FTE specific or the 1HD-T should have it too?

I wouldn't say its 1hd-fte specific, both my 1hz's had it too. More likely to do with what region they were sold in.

 

[mudgudgeon]

All sounds fairly normal.

I greea with @Locked79 the nipple is for air filter restriction sensor. My 1990 HDJ81 didn't have it.

A lot of manual boost controllers simply bleed boost pressure off to the atmosphere, so boost pressure is lost before it reaches the waste gate actuator. Adjusting the MBC simply opens or closes a vent to atmosphere. The bigger the opening, the more boost is lost, and more boost is needed to overcome the loss and get enough pressure to the actuator.

I think taking the wastegate pressure signal from the manifold not uncommon, but it possibly adds a bit of lag, so you may actually see a little more boost in some situations.