Atmospheric Pressure Sensor

[jandreu]

OK, I've been running on in other related threads about questions concerning how elevation changes effect the fuel/air mixture as the Nomad does not have an O2 sensor.

I was just flipping through my service Manuel and found a section on the fuel system service codes. It appears the Nomad has an "Atmospheric Pressure Sensor". I assume this is how the ECU adjusts for elevation changes.

Can anyone confirm this?

If this is in fact the means by which the Nomad copes with elevations changes does that mean that during a storm when the barometer drops the Nomad runs rich?

Inquiring minds want to know....

[macmac]

yeah more or less that's it, but it won't be so rich you can ride.. It just might be you get more power. If you want more look up old Bosch D jetronic

[Cajunrider]

I don't think barometric pressure fluctuates very much during a thunderstorm unless a tornado is passing directly over you or very close. The lowest pressure recorded during a Cat 5 hurricane was either in the very low 28.00 or high 27.00" HG. Large elevation changes will make much more of a difference. At sea level 1 BAR is 14.7 psia/29.92" Hg. At 10,000 feet above sea level the barometric pressure is 10.1 psia/20.58" Hg. That is a significant change that you'll never see in a thunderstorm. I know the #1 pot setting on my TFI is good here at sea level but is too rich above 8,000 feet. To make a long story short, I can't give a definitive answer to your question because I never ride in thunderstorms, hurricanes, or tornados.

[ercbf]

Found this, interesting reading.

http://books.google.com/books?id=wC2...page&q&f=false

[macmac]

Originally Posted by ercbf(Eric)

Found this, interesting reading.

http://books.google.com/books?id=wC2...page&q&f=false

Yeah, you got it, this is D jetronic a 1970 system, when it first came out. Thaty's all it is.... no smarts, no feed back, no air volume MAF. You move the throttle plate and it tells the ECU how much fuel.

A few other factors involved are bar, ambient temp, coolant, and that's just about it.

You can fool the ecu for 78 cents, in a phase. or you can fool it better with a TFI and or Cobra, and I always thought a PC III was to fussy, as of the ECU was fussissycated or something.

More or less when it gets boiled down ALL electronic FI systems are bosch.

The first O2 sencors as i recall were on CIS also called K Jet, next was LH jet.. LH has a platinum wire in the throttle body, and custiomers would break the wire thinking it shouldn't be there.

That made life expensive.

[cactusjack]

To make a long story short, I can't give a definitive answer to your question because I never ride in thunderstorms, hurricanes, or tornados.

Oh, so you're a "fair weather rider" then?

[ercbf]

Mac, what was the system in the old vw's. You know, they had a plate in the air filter assy that acted as an air meter and directly contolled fuel psi to the injectors

[ringadingh]

I know that in cold weather my bike smells a lot richer when I fire it up, Im assuming thats also because of the temperature sensor.

[Cajunrider]

Originally Posted by cactusjack

Oh, so you're a "fair weather rider" then?

When I can help it.

[ells]

+1 on what Mitch said, in his first post that is.

[Yellow Jacket]

Actually, there are two of them.

1. Inlet Air Pressure Sensor
2. Atmospheric Pressure Sensor

Both are the identical part but the Inlet sensor has a hose connecting it to the inlet.

Don't know the answer to the question but thought it was interesting.

[jandreu]

Eric and Mac, great info...

Cactusjack and Cajunrider great color.... ;)

Everyone else thanks for the input, got my answers as always..

[blowndodge]

I have to give you credit CJ (It pains me). I wouldn't ride in 115 degree weather unless it was a freeekin emergency. You, on the other hand don't mind it at all.. I still have nightmare over the 2008 Mesquite trip! That trip home from ZION had me jump in the pool with all my riding gear on as I thought I was dying!!