Over boosting

[weeksa]

Removing the arm from the stepper and cycled the vanes open and shut. Arm moved freely, no sign of sticking or resistance what so ever (was very surprised how easy it moved).

Might look for replacement stepper motor or turbo ecu

[babajangas]

I changed the turbo ecu driver over today car seems a bit more zippy and responsive but boost gauge still hits around 20 psi.while it was on the dyno mechanic said boost gauge (saas cheapy) was a reading few psi to high might swap it out for a good one before changing the stepper motor as I have already changed the map,maf,scv, and checked the veins .......I'll keep you posted
Cheers matt

[Talktheroo]

This is just a general comment about exhaust modifications.
Most of the Toyota designed diesel engines rely on back pressure of some kind.
The 1251 fault code is not one to be to worried about, and the restrictor plate, if you have one fitted, has nothing to do with this fault code.
The code that you will get if there is a problem with the restrictor plate is a P0400 fault code. This normally happens to plates that are smaller than the 7mm hole.
You do get more boost with this plate fitted as there are more exhaust gases passing through the turbine, mainly in low rpms.
With the Toyota electronic system (ECM and sensors) it's pretty good and reliable.
If there is something wrong you can usually see it through the DLC or the readings when you are doing a diagnostic test on the vehicle. MAF sensor error would throw a P0100 or related fault code. If it's the SCV, it will show up as a high out of specification reading. An example, above 2000mAs and the common rail pressure will be jumping around as well.
If you have a problem with the nozzle vane position sensor, it will throw a fault code P2563 or related code.
P0046 for a DC motor problem, or related.
Physical mechanical signs of problems with the turbo are oil leaks or not normal noises coming from warn bushes.
So, before you go ahead and spend a small fortune on a problem, it might be a good idea to get a diagnostic done.
Some companies that I deal with for turbo problems and supply.
Turbo Australia, Brisbane. GCG, Sydney. I do believe BDG sell them, as well. So get onto Matt and see what he can do for you.
Always replace your gaskets with new ones when replacing a turbo assembly. I like to use the genuine Toyota gaskets.
It's fairly uncommon for Toyota turbos to cause problems on the 1KDs. Usually it's a modification not done right, or a service problem where the engine oil has not be changed out, at least on the service book schedule. Every one has a different experience and I except that. This is my experience.
The Roo.

[weeksa]

Thank you The Roo.

Car is meticulously maintained, 5, 000km service intervals for oil, oil filter, diesel filter and air filter. I clean EGR and intake every 20, 000 and replace all gaskets while I am at it.

Problem started before I fitted my exhaust, no other modifications to the engine.

This has been happening for some time now and the only error code I ever got was P0046 while the car was idling a few weeks back.

I am in Sydney so might try GCG before I go an replace the stepper motor.

Appreciate your assistance!!

[weeksa]

Replaced Turbo Driver last week - no change at all, still over boosting badly.

[dano85]

No boost leaks?

[weeksa]

Replaced stepper motor on Friday - problem solved instantly and has been good ever since. Best $800 I have ever spent!

Thanks everyone for your help!

[Talktheroo]

Good on you, and fixed. The fault code system on the Toyota software is pretty reliable. Toyota is pretty conservative with electronics and that's a good thing. These vehicles are not racing cars, but utes with a purpose. That is for 4wding, daily drive and the trades for most of us.
The Roo.

[babajangas]

[quote="weeksa"]Replaced stepper motor on Friday - problem solved instantly and has been good ever since. Best $800 I have ever spent!

Thanks everyone for your help![/quote]
Hey mate is everything still running we'll has it fixed the problem about to go down the same path
Cheers matt

[weeksa]

Replaced stepper motor on Friday - problem solved instantly and has been good ever since. Best $800 I have ever spent!

Thanks everyone for your help!

Hey mate is everything still running we'll has it fixed the problem about to go down the same path
Cheers matt

Hi Matt,

Yes the problem is certainly solved. The power changed dramatically, much smoother and less 'bogged' down, more fuel efficient, not over boosting - it feels like a brand new car, so happy after 6 months of stressing.

I had the stepper replaced by GCG for just under $800. They will not supply the part only, you have to take the turbo out so they can fit it and align it. I couldn't afford the car to be off the road and and I am in Sydney so i took it off and drove it out there to be fitted. I have seen you can get the stepper motor on eBay for $550 but would recommend you get it fitted and aligned for the sake of $250-$300.

Good luck, let me know how you go.


Andrew

[babajangas]

Cheers mate awesome

[fracturedranga]

16psi is no problems, I was running 22 with the stock turbo before I started getting codes, got someone to turn your car on amd off (without starting it) and check the actuator on the turbo is moving it runs through the full range when the ignition is turned on. You could have a sticky vane in the turbo causing it to overshoot

[Talktheroo]

GCG is a pretty good company. I hope you had a good experience with them? The Roo.

[weeksa]

16psi is no problems, I was running 22 with the stock turbo before I started getting codes, got someone to turn your car on amd off (without starting it) and check the actuator on the turbo is moving it runs through the full range when the ignition is turned on. You could have a sticky vane in the turbo causing it to overshoot

I tested this numerous times before I replaced the stepper motor.

When ever I tested the stepper motor by turning the key on and off it worked fine, moved the full range up and down smoothly. This does not guarantee that the stepper motor is working perfectly / has no issues.

[babajangas]

Hi all after a lot of time and money I think I have got to the bottom of my overboosting issue today I pulled the vac line of the egr valve ( closest to drivers side) and car ran perfectly no overboosting at all. Could it be that a faulty egr valve is causing this? It would explain why it doesn't happen when cold because egr remains shut? I would love a bit of expert opinion before I go and replace the egr valve
Cheers matt

[babajangas]

Got the p0400 come up today cars is not going into limp mode just throwing a code can you keep driving it around with the vac line off and engine light on or will it eventually go it limp mode ? After overboosting for the last 6 months I had got so used to it hard to believe how much power is back
Cheers matt

[Gipsy]

matt the p0400 will come on and eventually go into limp after so many start/stop cycles unless you reset the code each time. I suggest you still have a problem and it is likely to be the egr valve or somewhere in the map sensor system. removing the vacuum line probably reduces the map to trick the sensor into seeing normal pressure hence the better boost you get

[babajangas]

Yep I keep resetting the code I suspect it is the egr valve as It had egr slime leaking out the little breather hole under the vac lines. I also noticed last time I pulled it apart there was no evidence of it opening and closing as the stem that moves up and down had no marking on it from when it slides up and down .I just bought a new valve and will get it on in the next
Cheers matt

[babajangas]

I'm pretty sure removing that vac line stops the egr from opening at all

[babajangas]

We'll replaced the egr valve today no good still over boosting not f$$$ing happy i hooked up the old valve to the vac lines and sensor to see if it was working correctly and it opens and closes as I accelerate so not sure what the problem is. Does anyone know if it is it safe to keep running with the vac line off it throws up a code now and again but no limp mode any one out there with any ideas of what to do next would be much appreciated I'm stumped
Cheers matt