Cant work this one out

IMAC

IMac
Can anyone shed any light or offer some advice if you've time.

In Aus with a 904 Sprinter 612.981.

My turbo boost works much better on a cool morning or evening than in the middle of a hot day, where the boost performance drops off guesstimation of up to 40%

I have a boost guage mounted on the dash.

Ive checked the wires of both boost temp and pressure sensors and all five wires have no earth leaks and have no breaks / open circuits.

The temp sensor resistance is responsive to temperature change (bic lighter) and 5volts at the supply.

The boost sensor has 5 volts at the supply both return variables have voltage fluctuation measured with a digital meter when rpm varies.

Can anyone comment on any possible calibrations / codings for the boost controls including the sensors and or vacuum solenoid.

And if so does one need a trip to a Dealer for their diagnostics gear.

Thanks


IMac
 

IMAC

IMac
Are any codes stored?



Can you watch Live Data for the boost actuator solenoid?
Thanks for your query. Im using a delphi clone probably from uncle Mao. There are no codes showing in the error code but the are a ****load of what would seem to be old codes stored, dont know much about the latter or there possible effects.
Thanks Ian MacDonald

IMac
 

IMAC

IMac
Imac.
You could have a vacuum leak, Where are you in Aus. Eric.
Thanks Eric.
Ive put a vac guage on the system from tube that is connected to the vacuum control unit and it comes down to 28 inches I stopped the motor and it held the 28 for well over 1hr.
But Im unsure of how long it is supposed to take to get down to max vac, though from cold start if one starts the motor then go stright to check the vnt linkage position, its all the way down. I guess thats about 20 second or less.
Thanks

IMac
 

IMAC

IMac
Thanks for your query. Im using a delphi clone probably from uncle Mao. There are no codes showing in the error code but the are a ****load of what would seem to be old codes stored, dont know much about the latter or there possible effects.
Thanks Ian MacDonald

IMac
Ill check out the live data issue and get back to you
[emoji106][emoji1037]

IMac
 

IMAC

IMac
Thanks for your query. Im using a delphi clone probably from uncle Mao. There are no codes showing in the error code but the are a ****load of what would seem to be old codes stored, dont know much about the latter or there possible effects.
Thanks Ian MacDonald

IMac
Hey Cheyenne.
The ****load of old codes is probably the software version number for the bosch build for the ECU.
There are no diagnostic trouble codes at all.
I checked it out again today at 1pm when things were a bit warmer but only about 24degC ambient and sure enough the boost performance was much lower than at 7am when it was about 18degC
Mmmmmmm
 

IMAC

IMac
Does it depend on fresh or recirculate air position
No there is no vacuum leak at the air recirculation actuator. Im sure its in the control side, but I dont have any info about testing the circuitry without an mb star diagnostics tool.
Thanks 4 your feedback

IMac
 

Top Bottom