problem with logging fuel pressure .

[bpman1234]

ok so i got the autometer gauge i hooked the signal wire to the analog 14 ajusted the settings in that notebook file to the settings on the sender 0.5 =0 4.5=100 and in the plc i used the analog 4 pressure 100psi b .sooo when i turned the engine on the pressure reads 100 psi .what do i do now .thanks in advance .also measured the signal wire that i put to the 14 analog and it has 5volts going to it is that wrong.also the auto meter gauge reads 36lbs at idle and moves and seems to be working fine.

 

[bpman1234]

anyone ?got any ideas .what i can try .what i can do .what it might be ?

 

[aminga]

Measure the voltage on the signal wire with a volt meter

 

[bpman1234]

ok will give it a shot in the morning thanks .

 

[bpman1234]

ok i have 2 signal wires wires coming out of the autometer box the one goes to the sender white that gives me 2.2 volts with23 lbsat the plc .the other goes to the gauge green.that gives me 5.72volts and 100 psi at the plc.all that time the autometer gauge is at 34 and my calibrated auto pressure gauge on the rail is at 36 psi.heres a pic of the sender the one to the left .thanks

 

[aminga]

The transfer function for that sender (to convert V to PSI) is 25*(V-0.5) so 2.2V should be 43 PSI.


According to this you should use the white wire. http://www.autometer.com/download_instruction/783h.pdf

 

[bpman1234]

so i should put the 2.2v in the plc file customs analog 4 psi where the minimum volt goes 0.5v or whee the max volt goes4.5? can you walk me alittle through it .

 

[aminga]

Measure the voltage again with KOEO on the white wire.

 

[bpman1234]

hey aminga thanks but whats koeo .

 

[TurboTdr3.8]

Key on and engine off

 

[bpman1234]

ok thanks gonna do it now be wright back

 

[bpman1234]

white wire is 2 volts koeo

 

[aminga]

So I forgot about the prime when the key comes on. Can you try it again but make sure the fuel pressyre has bled off, Unplug the ECM feed (orange wire by the battery) and try it again. I want to see the voltage at zero fuel pressure.

 

[bpman1234]

ok be rite back

 

[bpman1234]

ok its .46 with zero pressure .

 

[aminga]

Pretty close to 0.5

Edit PLC.ini on your laptop IF there is a custom analog 4 replace it with this or add itif it isn't there

[CustomAnalog5]
CustomAnalog5Name=FuelPressure
CustomAnalog5LongName=Fuel Pressure
CustomAnalog5Tag=FP
CustomAnalog5GaugeMin=0
CustomAnalog5GaugeMax=100
CustomAnalog5GraphMin=0
CustomAnalog5GraphMax=100
CustomAnalog5MinValue=0
CustomAnalog5MaxValue=100
CustomAnalog5MinVolt=0.46
CustomAnalog5MaxVolt=4.5

 

[bpman1234]

ok man i will give it a shot really want to thank you for your time .

 

[bpman1234]

ok i did that it got it closer to the autometer gauge 34psi and the plc reads 32psi is there anyway to get it closer .also while i was sitting there with the car idling the fans turned on and the psi dropped from 32 to 23-24 psi on the plc but the autometer gauge stood at the 34psi then when the fans turned off the plc psi went back up to 32 .

 

[aminga]

I wonder if you have some supply voltage problems. I don't know that I would sweat the temporary drops like that. It's there for reference.

 

[bpman1234]

Ok thanks gonna check all my connections before i put evrything back together .just want to thankyou again for your expertise.ill post with what i came up with have a blessed day.
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