Toyota Previa diesel 2002 lack of power valve timing?

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RYM6746
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Toyota Previa diesel 2002 lack of power valve timing?

Post by RYM6746 »

Hi guys I have a 2.0L Diesel D4D chassis number JTEGG32MX00009571. Its lacking power all the way through rev range (Feels like turbo is in-op) Visually turbo intake turbine looks fine (no free play) manually operating vanes on turbo makes little to no difference to boost pressure. EGR appears to open and shut in increments effecting the MAF reading using scan tool. Smoke tested intake system with no leaks. So I thought I would do the in cylinder pressure transducer test. I then realised this was the first diesel pressure test i have done ( which makes me question my results). To me it looks like the valve timing is off and there is no valve overlap. Is my theory correct or am i just interpreting the results wrongly? Could someone with more experience in in cylinder diesel pressure transducer testing steer me in the right direction please. Thank you very much for your time in advance.
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Dejan
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by Dejan »

Hy,
this is how I look on your in-cylinder pressure waveform.
EVO
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Dejan
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by Dejan »

EVC is around 30 degrees before TDC !
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Dejan
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by Dejan »

IVO
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Dejan
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by Dejan »

IVC
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Dejan
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by Dejan »

Hy,
looks like to me that exhaust is advanced.EVC is to early before TDC thus making "EGR effect".For the intake I'm not sure.

In situations like this,in my opinion,best thing to do is to compare measured valve angles with factory data valve angles if you have access to that info.

Never mind,I suspect that EVC is advanced.

Best regards and good luck,Dejan

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RYM6746
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by RYM6746 »

Hi thanks for the reply. I have tried to find Valve open and closing times for that engine with no success. I have always found it nearly impossible to find that data on any engine. I Also think the EVO is early which means it shuts early which means the piston is still in the upward direction against to closed valves hence the rise in pressure around the 360 degree mark
Last edited by RYM6746 on Sat Dec 26, 2020 3:25 pm, edited 1 time in total.

victor2k
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by victor2k »

Hello,
Here you will find the requested data about opening/closing valve timing
Best regards
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RYM6746
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by RYM6746 »

Thankyou very much. Where do you find such information. I spent hours looking for that?

victor2k
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Re: Toyota Previa diesel 2002 lack of power valve timing?

Post by victor2k »

RYM6746 wrote:
Sat Dec 26, 2020 3:21 pm
Where do you find such information.
In repair manual/NCF(new car features)/engine/valve mechanism

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