Forum/Expert Advice Needed 3.0L D4D Turbo.

[Reinart21]

Morning Gents,

My knowledge regarding turbo's are intermediate at best, and I need some help troubleshooting a problem.

I am going to assume that the basic mechanics of a standard O.E.M turbo applies. As this is not a aftermarket product.

I'm using a MadMan EMS 2, with the pressure sensor 0-5 bar (5VDO) to measure the pressure of the turbo.

Info: I've installed the monitoring system a couple months back, and have not had these erratic readings before. After spooling, turbo sits nicely at 0.8-0.9 bar consistently without problems.

Symptoms: Since last week Wednesday that the bakkie was serviced by Toyota, the boost pressure that the turbo drives are inconsistent. Sometimes when driving "rustig", boost pressure is maintained at previously mentioned amount. But putting foot the turbo will "sometimes" go past this to 1.2-1.4 bar and stay there, but I always throttle back, of course the alarm on the madman goes off.

Like I mentioned this has started very recently and I don't want to lose a turbo due to something faulty?

[Hiluxfan_111]

Sounds to me like the wastegate isn't working properly.
Check if they didn't perhaps remove or damage the small hose to the actuator when they did the service.

[Reinart21]

There is a small black hose that was tapped in with a T piece to get to the pressure sensor. I'm guessing that is the hose that you are referring to as I'm not sure what an actuator is.

One thing to note, since this has started, I could be paranoid but the car pulls a bit less, and my exhaust gas temperature does not rise as quick or go as high as it used to, so I'm guessing the engine is not performing or combustion with the same vigor as before, but I'm only guessing here.

[4x4BEES]

Maybe they put a new map on the EMU when you had it serviced?

[Reinart21]

Maybe they put a new map on the EMU when you had it serviced?

Would they do that without the knowledge of the client? That would not be very professional. The bakkie is long been out of its warranty service plan, ODO at 142 000 kms.

[4x4BEES]

They did it a friend of mine's bakkie, but he is still in his service plan.
Was part of some upgrade, but his didn't pull worse, or better, for that mater.

But they told him after the service was done.

[Hiluxfan_111]

Hi Reinart
Yes that sounds like the correct hose. Its a small one of about 5mm diameter.
It goes to a little canister thingy on the turbo. This has a rod connecting it to the wastegate valve on the exhaust side of the turbo.
I'm not a D4D expert but I don't think boost is ECU controlled, so a new map will not have such a big influence on boost.

[JohanW]

Increased boost will cause the engine to run leaner. Without increasing the amount of fuel injected higher boost won't give you more power. AFAIK the d4d turbo has a mechanical wastegate that opens at a set pressure. The ECU will change the amount of fuel injected to protect itself. So it could be that less fuel is injected due to this abnormal high boost level. The answer is a phone call away. Call the service department.

[Reinart21]

Increased boost will cause the engine to run leaner. Without increasing the amount of fuel injected higher boost won't give you more power. AFAIK the d4d turbo has a mechanical wastegate that opens at a set pressure. The ECU will change the amount of fuel injected to protect itself. So it could be that less fuel is injected due to this abnormal high boost level. The answer is a phone call away. Call the service department.

So my bad, I did not mention I have a Dastek Unichip installed, but for more than n year now with no problems.

So please assume all previous info given is correct with the Unichip installed.

[JohanW]

Time to book a dyno session then.

[Reinart21]

Reporting back:

So I'm going to write this one up as experience, and maybe we can all have a good laugh.

Had the bakkie at a friend with some knowledge of turbo's etc, inspected what we could see, he mentioned that my boost pressure sensor on Madman unit possibly had a bad earth connection, so that should be sorted first. Got the right size ring lugs and sorted the earth out. Boom, there the readings on boost pressure was back to normal. 0.9 all the way.

On my way home from work, I noticed that the extra rubber mat on the driver side was swopped with the passenger side, which meant the pieces trimmed to keep from going under my fuel pedal was now exactly there, under my fuel pedal, kept me from being able to test at full throttle. This kept the Exhaust Gas Temperature from rising quick and as high as what I'm used to, coupled with erratic boost readings had me worried. The rubber mat switch happened while after servicing at Toyota they usually clean the cars and I did not notice till now...

"Praat van spoke opjaag"

Thanks for your input guys, was on our way to troubleshoot some "real" problems...

[4x4BEES]

Just glad it's sorted now

[Mars]

Goeie een. Dankie dat jy dit gedeel het.