# boost contoller and voltmeter problems



## SubaruBlue200sx (Mar 21, 2004)

ok so today i attempted to install my greddy type s boost controller.. it gets power. yet it will not increase boost..at all.

i also attempted to install my cyberdyne digital voltmeter gauge to monitor my maf voltage only. it has 3 wires black = neg red= 12 volt source. and purple = dimmer. the red i had connect to ign and the purple to the maf sensor.. all i got was the normal 13.9 voltage. then i connected red to the maf ..got nothing.. then i connected purple to the 12 volt source.. nothing
ground was grounded to chasis. 

any ideas ?


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## chimmike (Oct 17, 2002)

well how did you install the controller. The vac lines, etc, how did you install them.


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## SubaruBlue200sx (Mar 21, 2004)

chimmike said:


> well how did you install the controller. The vac lines, etc, how did you install them.



well obviously i ran power to the controller itself.. i have a vaccum distribution block for my intake manifold where the boost gague and bov connect to.. i have the controlller's vac line comin from there
the soleniod has 3 spots to connect COM, NO, NC. direction say to use Com and NO... Com was connected to the actuator. NO was then connected to the intake piping.


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## wes (Apr 30, 2002)

Voltmeter input. What voltage is it designed to read? The MAF voltage is a MAXIMUM of 5.11 volts. Can it read less than 1V? 

The purple obviously does not connect to the MAF. It is for an internal light I am assuming... The red wire should be the source of the voltage you wish to read. 

Test it in the engine bay and go from there.


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## SubaruBlue200sx (Mar 21, 2004)

wes said:


> Voltmeter input. What voltage is it designed to read? The MAF voltage is a MAXIMUM of 5.11 volts. Can it read less than 1V?
> 
> The purple obviously does not connect to the MAF. It is for an internal light I am assuming... The red wire should be the source of the voltage you wish to read.
> 
> Test it in the engine bay and go from there.



nope.. it cannot.. the gauge i have will only ready 8v-18v
where can i get a gauge that will read enough just for the maf sensor
and any ideas on my boost controller?


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## wes (Apr 30, 2002)

SubaruBlue200sx said:


> nope.. it cannot.. the gauge i have will only ready 8v-18v
> where can i get a gauge that will read enough just for the maf sensor
> and any ideas on my boost controller?


forget the gauge, use a multimeter rigged up for a couple of days. That will give you a good enough idea and will not be a permanent gauge install. Otherwise the techtom can read MAF voltage. 

Sounds like the lines are hooked up right. Now go back through the instructions and re-do all your connections.


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## dundee (May 11, 2002)

Wes,

Out of curiosity were did you find the value 5.11v? Because the our ecu uses a clone of the Motorola 68HC05 microcontroller which is a 5v device. It makes sense then the analog to digital converter has a range from 0 to 5v. Now they could very well be scaling the input for a wider input voltage range. Or maybe an external A2D... Anyway... just curious


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## dundee (May 11, 2002)

actually I think this makes sense... You got this reading from the consult port right?

http://www.nissanforums.com/showthread.php?t=52695&highlight=5.11

well that's because 0-511 is the scale of a 9-bit binary number (2^9 = 512) The ecu must be using a 9 bit a2d or maybe a 10bit signed a2d (-512 to 511)... It would be interesting to actually measure the voltage across the MAF when the consult reports 5.11v.


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## wes (Apr 30, 2002)

dundee said:


> actually I think this makes sense... You got this reading from the consult port right?
> 
> http://www.nissanforums.com/showthread.php?t=52695&highlight=5.11
> 
> well that's because 0-511 is the scale of a 9-bit binary number (2^9 = 512) The ecu must be using a 9 bit a2d or maybe a 10bit signed a2d (-512 to 511)... It would be interesting to actually measure the voltage across the MAF when the consult reports 5.11v.


That is the value the ECU uses. 5.12 being the theoretical max. with 5.11 being the max displayed value. I actually got this number from talking with JWT about MAF voltage when I first got my car running with the T28. I noticed it would hit 5.11 and not rise above that.


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## dundee (May 11, 2002)

Well I'm not disagreeing with you... the max voltage reading the ecu outputs is 5.11. The ADC (analog to digital converter) the ECU uses to sample the MAF voltage, most likely has a maximum digital value of 511 because the nature of binary numbers. Reading it out of the consult port is the best way to tell if the MAF or ADC is maxed out, because you see what the ECU sees. What I am saying is by hooking a multimeter directly across the MAF the scaling might be slightly different. You might read 5.00v when the ecu says 5.11v, or it may even drive past 5.11v. One thing I know for sure is reading through the consult port is the best way, because those are the numbers the ecu is directly using to calculate its real time fuel / timing / etc algorithms.


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## wes (Apr 30, 2002)

I have taken readings AT the actual MAF and I also have the techtom which reads the consult port, they read the same... 

Your the EE here, I just know what the max voltage is and when I have reached that max.


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