Map sensor readings off

[ovlov760]

At 20psi I'm getting a reading of 217-220kpa in MT. I don't recall this being an issue before? I checked both my boost gauge and megasquirt against the air compressor. Boost gauge reads exactly as the air compressor does while megasquirt does not.

[WizuhD]

maybe something is kinking the line reducing the air flow?

[JohnLane]

Maybe the MAP sensor is sheet?

[The Aspirator]

Eh, be happy with it, it means you can run like 26psi before the tables get maxed out ;-).

[Boris740]

At 20psi I'm getting a reading of 217-220kpa in MT. I don't recall this being an issue before? I checked both my boost gauge and megasquirt against the air compressor. Boost gauge reads exactly as the air compressor does while megasquirt does not.

What were you expecting to get?

[JohnLane]

If it is consistent you can make up your maps to work with it. This may be a blessing.

[ovlov760]

What were you expecting to get?
240-250kpa?

[Boris740]

240-250kpa?

That is close to the full scale output. In terms of voltage that is around 4.6V D1 probably starts to partially conduct around that voltage and is limiting your signal. You don't not need that protection diode. As the matter of fact you do not need D1,D2,D3 and D4. D1 is not installed, check what that voltage is on both sides of R2 at 20 PSI.. It should be around 4.6 Volts on either end because there is no appreciable current flowing through it.

[linuxman51]

for 20psi you should be looking for a kpa reading in the 225-235 range (with it ideally being closer to 235)

[Lord_Athlon]

I agree, if you can make the maps work with it, its a blessing.

[ovlov760]

for 20psi you should be looking for a kpa reading in the 225-235 range (with it ideally being closer to 235)
I did not know that. Does this mean I do not need to make fuel/spark maps that go to 250?