TD4 Turbo Boots PSI

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thomas2005rugby

New Member
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23
Hi all
I have had a look around but I can’t find any thing on the normal psi and what the max psi is for the turbo on the mark 1 td4.
I have just got a manual boost control and a boost gauge and I am looking to fit it but I was looking to see what the standard PSI for the turbo is and what the maximum PSI I can get away with without damaging the car is? :rofl:
Any thoughts would be great
Thanks
Tom
;)
 
Hi all
I have had a look around but I can’t find any thing on the normal psi and what the max psi is for the turbo on the mark 1 td4.
I have just got a manual boost control and a boost gauge and I am looking to fit it but I was looking to see what the standard PSI for the turbo is and what the maximum PSI I can get away with without damaging the car is? :rofl:
Any thoughts would be great
Thanks
Tom
;)

Mitsubishi or Garrett?

If its a Mitsubishi then according to Haynes the max boost pressure is 1.765 +/- 0.03 bar.
 
It's a variable vane turbo under ECU control. There's no wastegate so you can't alter the boost. Just fit a Synergy 2 instead.
 
It's a variable vane turbo under ECU control. There's no wastegate so you can't alter the boost. Just fit a Synergy 2 instead.
You can alter the boost by driving the signal to the boost solenoid manually. I would also like to know what range of boost is normal and maximum allowed.
 
I’ve fitted the synergy2, but it only alters the fuel rail pressure and MAF readings, so doesn’t directly drive the boost solenoid. It relies on the ECU to adjust that as it seems fit. My ECU doesn’t seem to drive the solenoid enough. By powering the solenoid directly you can get more boost it seems. This is especially noticeable at 2500 rpm (idle) where I get white smoke if the ECU drives it but not if I power the solenoid directly. It seems the engine is not getting enough air at those revs and chucks out unburnt diesel.
Until I completely get to the bottom of why this is I’ll make up a simple boost controller next week and use that.
So far I’ve checked:
- boost solenoid and actuator
- MAP sensor readings and turbo hoses / intercooler for leaks
- HP fuel rail pressure readings (fixed hp fuel pump regulator seals and checked hp sensor wiring/volts)
- crankcase filter changed and oil cleaned out of everything on inlet side, intercooler etc.
- LP Pump and filter changed
- tried pierburg MAF /synergy2 and Bosch MAF, with or without synergy2
- checked for blocked cat
- egr blanking in
- vacuum lines checked for leaks. One slight one on pipe to egr, so blocked that as not used.

I’m thinking maybe there is not enough vacuum present possibly (although there is enough to fully pull the turbo actuator when the solenoid is manually driven).

Does anyone have a cunning/cheap way to measure the vacuum from the vacuum pump? And what value it should be?
 
Last edited:
Does anyone have a cunning/cheap way to measure the vacuum from the vacuum pump? And what value it should be?

You can buy a vacuum test gauge for very little money. The vacuum would generally be about 20HG, which is what the brake servo is designed to work at.
 
Thanks, I’ll have a look around for one.

My own TD4 auto gives a vacuum of 21HG, which is about right. What I do notice, is the vacuum drops away over night. It then takes about a minute or so after starting, for the full vacuum to be restored.
 
My own TD4 auto gives a vacuum of 21HG, which is about right. What I do notice, is the vacuum drops away over night. It then takes about a minute or so after starting, for the full vacuum to be restored.
Thanks interesting and useful input. You were right about not much money. Found a combined vacuum and turbo boost guage on ebay that I can use for both and install in the car later. Good result. £9. https://ebay.to/2PaAQxM
 
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