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Lack of power and turbo boost

Saffe

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Jan 5, 2015
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38
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belgium
Hi all!

I have bought an 1990 LJ70 with the 2LT-TD engine (340.000km) last year and since then I changed the following:
- air filter
- fuel filter
- revised turbo with a turbo cartridge/CHRA

In the beginning the car stalled a lot and had very little power/torque. So I changed the fuel filter (which was full with slug and water), air filter and turbo and the stalling was gone. But I still miss the power/torque, I adjusted the amount of injection until there was a bit of black smoke but no increase of power...
I have another LJ70 LX-turbo with approximatly same age and km'ters/miles but it has almost the double amount of power. It is very noticable when I go offroad, go uphill or just start of on the red lights.
Also, the green turbo light of the LJ70 only comes on around 3000 rpm, while the LX has it already at around 2000 rpm...

So, anyone an idea what it could be? The wastgate works properly and I even "tuned" it by latening the opening, no cooling in oil or oil in cooling.
 
Btw, does my type LJ70 have already an ECU I can read out?
 
If it a 2lt then no ecu isit the right cartridge for turbo??
 
If it a 2lt then no ecu isit the right cartridge for turbo??

Yes it is. No Toyota because a new Toyota turbo was too expensive. But the power loss was already before I repaired the turbo.

I will check the compression rate this weekend. Is there a possibility that the valve clearance gets too big after a while? I think it is the opposite way but just to be sure.
 
Search the web for 2LT boost compensator and you might find your answer .
 
No I think the compression rate will be fine and clearances
have u checked watergate?? I brought a new turbo for mine when was a 2.4 I brought off eBay was only 145.00 I think?? I'll try and get item number for u. Made a difference to my old turbo
 
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Hello guys. It's been a while now :) I checked the boost compensator and changed it, without succes. Someone else an idea? Maybe some dirty fuel lines? Valve clearance? Injection timing? Engine starts perfect, no smoke, no excessive mpg,... I'm out of options
 
Leaking vacuum lines , check or replace the one on the turbo actuator first . Could also be a leak in the intake so turbo is not getting up to pressure .
 
Leaking vacuum lines , check or replace the one on the turbo actuator first . Could also be a leak in the intake so turbo is not getting up to pressure .
I checked the vacuum lines, should be fine. Around 3500-4000 rpm the stock boost indicator led goes red, green around 1800 rpm. So there is no leak in the intake I guess and also indicates the boost pressure is sufficient, right?

Could be a split boost diaphragm?
I checked the boost diaphragm and it is not torn.
 
Pull the drain plug on the fuel tank and have a look for fuel contamination as any black type sludge or brown hair type strands as you may have a fuel bug problem. Does your truck have a water separator normally bolted under the front right hand seat on the chassis rail.
 
Pull the drain plug on the fuel tank and have a look for fuel contamination as any black type sludge or brown hair type strands as you may have a fuel bug problem. Does your truck have a water separator normally bolted under the front right hand seat on the chassis rail.

I found out that there was some "sludge" in the old diesel filter, and also water in the water separator (bottom of fuel filter mount). But I never checked the fuel lines or tank because the new diesel filter still looked clean after 500km.

Is there another filter beside the one near the engine in the left of the engine bay? Maybe one in the tank? Where is the (low pressure) diesel pump located, maybe I try to run it manually with the fuel line disconnected to see if the fuel supply is sufficient?
 
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Could possibly be one in the tank, and maybe inside the pump. Doubt it, but theres a possibility.
 
I looked into the 2LT manuel and found the following cause of lack of power:
LackOfPower.png
Does anyone know where those 2 screws are located? The previous owner overhauled the cruiser almost completely, so maybe he interchanged the 2 screws. Google does not give me any more info...
 
There is a mesh filter on the fuel pick up in the fuel tank.

Also might be worth checking all the fuel lines running from the tank to the fuel filter in the engine bay, to check there not corroded or damaged. :thumbup:
 
Being a manual pump i assume there is room for adjustment at the pump itself , now i don't know the 2LT but i wonder if this pic might shed some light on things

pump.jpg
 
Being a manual pump i assume there is room for adjustment at the pump itself , now i don't know the 2LT but i wonder if this pic might shed some light on things

Hi Shayne and Ben, and thank you for the effort. I already changed the position of the full load screw, with some black smoke at full throttle as result. However, the power stays the same. On top of the pump you can see the boost compensator, the bolt on top has no use and is a bit loose (thread not 100%). I am not sure if it is still air tight, I might check this also this saturday.
Do you know what is the use of that bolt? (it is a real short one).
 
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You replaced the boost compensater but you don't know know if its air tight ?

If its not air tight it can't work . The pump mixes fuel and air in set proportions throughout the rev range as if you have no turbo at all . When a turbo joins in the pump cannot keep up unless a functioning boost compensator tells it to match the now compressed air being forced into the engine with adequate fuel . The motor will run so lean it will feel like the revs are climbing but there is no corresponding increase in speed , like it wants to go but it can't .
 
I did not replaced the boost compensator, I only checked if the diaphragm was cracked and I changed the settings. Sorry English is not my native language, I did not mean replaced the boost compensator but only changed the settings :).
I will post an update on saturday evening if I solved the problem. Thanks so far for your help!
 
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