MAP sensor wiring help PLEASE!

[terra]

Okay, checked my car again. I apparently have the MAP on pin 17, IAT and flap position sensor on pin 16.

Decided to do some quick logs flipping the pins around:

MAP on Pin 16 (the blip you see is me pressing the throttle for a second)



MAP on Pin 17



Both look pretty much the same to me. Engine was completely cold for the first test (pin 16) which should explain the slightly higher resting pressure.

I also checked my with my multimeter, the two pins register as continuous to each other and continuous to ground for me.

[Cubieman]

Okay, checked my car again. I apparently have the MAP on pin 17, IAT and flap position sensor on pin 16.

Decided to do some quick logs flipping the pins around:

MAP on Pin 16 (the blip you see is me pressing the throttle for a second)



MAP on Pin 17



Both look pretty much the same to me. Engine was completely cold for the first test (pin 16) which should explain the slightly higher resting pressure.

I also checked my with my multimeter, the two pins register as continuous to each other and continuous to ground for me.

Thanks, great info there.
What do you think would be causing my readings to be bounce up and down as much as they are? Also my readings are slightly out of normal range.


I am going to swap pins so IAT would be grounded on 16 and MAP on 17 and see what happens on Testo.

[terra]

Your reading with the engine off seems fine to me. You can do a sanity check with a barometer app on your phone (and really the barometric reading from the DME is somewhere within testo too). If it's within 50 mbar of atmospheric pressure, I wouldn't sweat it.

Engine on seems is what's weird. My first thought would be a wiring issue, but I do have to wonder if the sensor being mounted basically directly to a throttle body instead of further downstream causes oscillations like that. I haven't seen others complain of that though.

[ATB88]

Your reading with the engine off seems fine to me. You can do a sanity check with a barometer app on your phone (and really the barometric reading from the DME is somewhere within testo too). If it's within 50 mbar of atmospheric pressure, I wouldn't sweat it.

Engine on seems is what's weird. My first thought would be a wiring issue, but I do have to wonder if the sensor being mounted basically directly to a throttle body instead of further downstream causes oscillations like that. I haven't seen others complain of that though.

Yeah I've had a curiosity in the back of my mind in the last few months as I prep for a CSL box whether putting the MAP where Kassel does might cause some weirdness in the signal since it's so close to a TB opening. I always assumed no or not appreciably because so many people seem to run it without issue, but, still, very curious.

[Cubieman]

Swapped pins, this test was with MAP ground to pin 17 and IAT ground to pin 16:

Ignition position 2:
Igniton on (cold start):

[terra]

So pretty much the same. I'd check the other two pins on the map sensor are making good contact.

Reading change at all when you give throttle?

[Cubieman]

So pretty much the same. I'd check the other two pins on the map sensor are making good contact.

Reading change at all when you give throttle?

The reading changes with throttle. Pin 18 (Signal) is firmly seating in block via factory type termination. However pin 7 (Power) is attached via a T-tap, when I test for voltage on the spade going into the tap I get 5VDC. I plan to solder but wanted to tap first just to make sure everything worked.
And again this car smells like it is running rich, and again that probably is just a result of the tune.

Maybe there is something to the location of the sensor itself, I do have the other type connector that would go on the brake servo line. Would be kind of pain though because I would have to re-route all my beautiful wiring, but I am curious.

[duracellttu]

Is there any reason to believe that having the MAP sensor in one location versus another has any affect on the accuracy of the reading? Comparing the most popular solutions 1) OEM air rail 2) Kassel 3) Inline adapter from a hose

[Cubieman]

Could my routing of the MAP wiring so near the fuel injectors have anything to do with getting this strange signal?

[Cubieman]

Is there any reason to believe that having the MAP sensor in one location versus another has any affect on the accuracy of the reading? Comparing the most popular solutions 1) OEM air rail 2) Kassel 3) Inline adapter from a hose

I may be able to test that.
I'm thinking of doing a test where I take my wire out from right beside the fuel injectors (where I have a theory that they are causing signal interference) and over the air box to the DME. This test would keep the location of the MAP sensor itself the same (Kassel adapter).

The next test would be to use my inline MAP adapter.

Those two tests may be able to determine if wiring route and/or MAP position have anything to do with my strange readings.

I just really don't want to pull those wires I spent so much time routing and de-pin too many times as I fear the locking tabs on the pins might only take so much abuse before they don't work. But I am quite curious and there is only one way to find out!

[COVID-19]

I may be able to test that.
I'm thinking of doing a test where I take my wire out from right beside the fuel injectors (where I have a theory that they are causing signal interference) and over the air box to the DME. This test would keep the location of the MAP sensor itself the same (Kassel adapter).

The next test would be to use my inline MAP adapter.

Those two tests may be able to determine if wiring route and/or MAP position have anything to do with my strange readings.

I just really don't want to pull those wires I spent so much time routing and de-pin too many times as I fear the locking tabs on the pins might only take so much abuse before they don't work. But I am quite curious and there is only one way to find out!

I was going to test mine but my computer doesn’t like my car. Curious to see your results. I still have more adapters incase anyone wants to do some testing lol

[Cubieman]

I was going to test mine but my computer doesn’t like my car. Curious to see your results. I still have more adapters incase anyone wants to do some testing lol

I had to switch my USB cable to COM9 for the Testo program to work. Usually I think you'll have it set for COM1 for INPA. But I really don't know much about those things. Just really glad my computer and car like to play together!

[COVID-19]

Got it to work. My car was kinda warm already BTW. I don’t seem to have a fluctuation at idle.

[jbfrancis3]

Great stuff. Will Testo log IAT's?

[Martyn]

I’ve been using pin 16 for 6 years. It works fine.

Likewise.