pop-off valve problem. where to source (1994) L400 turbo or wastegate

Mitsubishi Delica L400 production commenced in 1994 -- After much anticipation, the L400 arrived on Canadian Soil in 2009!
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myme22
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by myme22 »

Hi

I have had an ongoing problem with the intake manifold pressure relief valve popping all the time.
I have been told it's probably a defective/stuck turbo wastegate, and am trying to source a turbo and/or just the wastegate.

Anyone have any good trustworthy aftermarket part numbers and suppliers?

I also have been told to just put a plug in where the pop-off valve is, because the turbo is not powerful enough to overpressure the engine...
However, according to some professionals, it is absolutely necessary to keep the valve...
Any input would be greatly appreciated!

Thanks
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jos_mclean
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by jos_mclean »

it is pretty common for the actuator arm of the turbo watergate to stick, and cause the relief valve to open. try sprain lube(wd40) down the arm where it meets the turbo. should free it up and solve your problem
204explorer
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by 204explorer »

Before spending hundreds of dollars on parts, i would do two things. Move the waste gate actuator by hand (with a pry bar) and check the pressure of the intake manifold when your blow off valve opens (should be around 14psi). You could have a weak blow off valve.

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archieim
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by archieim »

Is it common to have a blow off valve? Do some years have them and other not?
What is the purpose of it?
Can I delete it or is it factory?



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204explorer
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by 204explorer »

I am not sure if all models have it. My 95 l400 has it. Its there to protect the engine from too much boost pressure in case the waste gate actuator linkage does not function. Normally the waste gate limits the amount of boost. So if it has a blow off valve, i would leave it in and make sure it functions correctly.

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archieim
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by archieim »

Mine seems to go off often. It could be me hammering on it all time. Is it possible my waste gate is not functioning properly?
What is normal?


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204explorer
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by 204explorer »

Mine never blows off. I cant hear it anways. Try to move your waste gate linkage by hand (with a pry bar). I believe there is a topic on that somewhere in the forum. Lubricate it with a rust penetrating oil.

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Growlerbearnz
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by Growlerbearnz »

As 204Explorer mentioned earlier, the pressure relief valves sometimes get weak with age. The only way to know if it's the relief valve popping to early or the wastegate allowing too much boost is to fit a boost gauge and see what pressure you're making.

Stock boost is 11-12psi maximum, the relief valve should be popping at about 15psi.
Nothing says "poor workmanship" more than wrinkles in the duct tape.
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archieim
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by archieim »

I have a gauge it's going off at 14-15 psi. I'll have to look into my linkage and see if I can turn it down or lube it up!
I'm also thinking it could be the fact that I'm at 3500 ft above sea level and these things are made to drive a sea level. I've seen that before with mountain sleds and dirk bikes. Even my "on demand" hot water system had a setting on it for elevations over 3000 ft.





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Growlerbearnz
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by Growlerbearnz »

Righto, so if it's popping at 15psi then the valve is working just fine, it's your wastegate that's not working as intended. Before you adjust anything though, just check that everything is working properly- altitude does increase boost, but 15psi seems a little much.

Check for extra washers under the wastegate actuator mounting canister- it's a common way of increasing the boost. If your actuator rod is adjustable look for evidence of tinkering- burred edges on the nuts, exposed clean threads, that kind of thing.

Pull on the actuator rod and see if it moves. It's a heavy spring, but you should be able to move it by hand. You might need self-locking pliers to get enough grip on the actuator rod.

If the rod won't move, try disconnecting it from the wastegate lever on the turbo and see if the lever moves freely. If the lever is jammed you might be able to free it by moving it back and forth repeatedly. I'd avoid oiling the shaft, as it gets super hot and any oil would get baked to carbon.

Try applying air pressure to the wastegate actuator- it should start to move at about 8psi. Alternately, suck on the actuator hose and see if it holds a vacuum. You're testing to see if the actuator diaphragm has a hole in it.

http://www.dieselarmy.com/engine-tech/b ... ochargers/
Nothing says "poor workmanship" more than wrinkles in the duct tape.
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archieim
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pop-off valve problem. where to source (1994) L400 turbo or wastegate

Post by archieim »

Thanks Growlerbearnz
The only reason I suspect or I'm leaning towards altitude is because air pressure changes way up here.
If it was a dirt bike, I'd change the jets in the carb and tune it from there. Maybe play with the oil and gas ratio's.
I read your link you posted and it sounds like I'm on the right path.
But I should make sure everything else is working properly first.
I found a local diesel shop that referred me to a guy the wrenches on Delica's. I hopping he might have some answers.



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