Soooo

I pulled this little part off of the 190E I'm parting. I didn't know what it was, so I ran the part number. It's described as both a "pressure sensor" and an "altitude adjustment sensor."

I'm assuming there's some sort of afr adjustment done by this part, from referencing atmospheric pressure from the nipple? Does anyone know how this part actually works? Anyone know how much pressure it will measure and what voltage range it operates in?

I ask because, if what I've assumed about the part is true, it could be used for fuel enrichment in a turbo application (with a boost reference line on the nipple). Just a little idea I had during the boring parts of the day.

Here's a picture of the part itself:

you're correct in that it's an altitude compensator. i'm sure there's specs someplace in the service manual, but i've never tested nor replaced 1 for any problem.

can you cheat with it? don't know but i doubt there's enough change in it to make it worthwhile. otherwise, the saab and volvo turbos would already use it. good luck, chuck.

That sensor has minimal impact on air/fuel ratio. You could unplug it and never notice any difference in how the engine runs.

I was thinking of utilizing it on my Volvo project.

I feel like that's based on the way the ECU interprets the signal. That could be changed...?

I'm sure the signal could be changed but it still wouldn't make much difference. The altitude information simply doesn't play a very big part in the fuel calculation.

It's something to think about at least. It may not play a large part simply because the atmospheric pressure does not change that much depending on altitude. If you fed the sensor an artificial atmosphere (like boost), the affect may be greater. The trick would be to find out how much pressure the sensor will register in it's signal before it tops out.

you're working at this way too hard.

if it's a kjet turbo, then get a saab apc kit. there's info on turbobricks.

if it's an lh turbo, then look for a turbo plus kit on ebay. just get the right year kit for the car. good luck, chuck.

I think no one know properly how it works...

And it couldn't be used for fuel enrichment on the KE-Jet turbocharged engine.
First, because it just couldn't used for this.
Second, because KE-Jetronic with turbo don't need this device per se.

i do know how it works. there's a 5v reference voltage from the ecu and a ground. the return signal is 4v or less, depending on elevation. the problem with the op is the ecu would have to be rechipped or something to get any NOTICEABLE change in mixture.

like ILUVMILS said, unplug it and see what change there is in running-none. at least here at sea level. found them unplugged many a time after someone installed an air filter in an e30 325. very easy to forget as once it's all together, the harness gets buried.

because it's free, that may the only motivation. this won't provide something for nothing. and so it goes, chuck.

This is something I would use with an LH-jet 2.2 or 2.4 ECU, not the stock KE-jet ECU.

Now that there has been a bit of churn about this sensor, please keep in mind the intended purpose:

To provide a correction for operation of the engine when ABOVE sea level. Hence the only correction that can occur is for a DECREASE in atmospheric pressure. The sensor in question is not designed for operation with INCREASED manifold pressure that would result from any form of supercharging.