ECMlink GM Style 4 bar map sensor (generic) - runs rich after replacement

[ErikTande]

I'm having a problem that I think I have narrowed down to a bad map sensor. On the car now is the OmniPower GM-style 4-bar MAP sensor that I ordered from ECMLink with my SD setup.
http://www.ecmtuning.com/product_info.php?products_id=47

However, I think it's going bad (car randomly won't run but if I unplug the MAP sensor and plug it back in the problem goes away temporarily).

So I ordered this cheap replacement from Amazon, and it looks identical to the unit from ECMLink, minus the OmniPower markings.


https://www.amazon.com/gp/product/B01M59MHRF


When I plugged it in the car starts but runs WAY rich (10.9). Does this generic unit need to be calibrated in anyway? Or do I just need to shell out the $100 for a real one from ECMLink?

Thanks!

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[lasthope05]

You need to find the spec sheet on that particular sensor and input those values as a user defined sensor.

You could also log raw map voltage and use a hand held vacuum/pressure gauge. Pull full vacuum and input as min voltage @ 20kpa. Do the same for boost and that is your max voltage @ 400kpa. Give that a try and hope the sensor is linear.

 

[ErikTande]

I messaged the seller and I'm still waiting for a response. In the mean time I found this link:
https://perfecttuning.net/en/accessories/59-gm-4-bar-map-sensor.html
and they have the specs listed as "3.5 kPa at 0 volts and 416.5 kPa at 5 volts."

Assuming that is correct for my sensor, what values would I enter into ECMLink and where?

Thanks again!

 

[bastarddsm]

Convert those 2 points to psi. then plot them and find the slope (psi/volt) and where 0psia (offset)is.

 

[ErikTande]

OK so google tells me
3.5 kPa = 0.507632 psi
416.5 kPa = 60.408218 psi

How do I plot them and find the slope and where the offset is? (That's all greek to me sorry : P)

 

[lasthope05]

Easiest way to find it is to use the method I told you above with a vacuum pump and log raw voltage for min volts. Since it's a 4 bar use a -29inhg for min volts and 45psi for max volts. Use a compressor(or the same pump if it has pressure) to Max out the sensor to get your max volts. That will get you into the ball park and you can fine tune from there.

 

[Mello]

From the values you posted your slope would be 11.9801172 psi/volt

 

[1990TSIAWDTALON]

Try a different sensor so you KNOW its the sensor giving you problems Erik.

 

[ErikTande]

Try a different sensor so you KNOW its the sensor giving you problems Erik.

That's what I'm trying to do

 

[1990TSIAWDTALON]

Got ya! I had a funky Omni bar sensor too and just replaced it with a new one from EcmLink. (they offered to replace mine, and look at the old one, but that was a couple years ago). It seemed to fix the problem I was having and I am not sure now exactly what was goofy with it but I did replace it. Surely someone in the Colorado area has one to test with.

 

[ErikTande]

From the values you posted your slope would be 11.9801172 psi/volt

Ok, so I'll plug that number into the spot in link. What would the "volts(user defined)" be in that case?

Thanks again!

 

[Mello]

Try -042373 volts.

 

[ErikTande]

Try -042373 volts.

Cool, no decimal, right? Also, how did you come up with those numbers? Hopefully I can try do it myself next time!

 

[Mello]

sorry has a decimal. Use -.042373 volts

 

[Falcon91]

Don't mean to thread jack here, i'm currently running a GM 3 Bar map, i'm upgrading my turbo and will be running more boost (30-35psi). Can i use the plug for the 3 bar for the new 4 bar or are the plugs different?

 

[Vegas Smith]

Should be the same if it's the same brand.

 

[92AWDHX40]

Same plug .

 

[Falcon91]

Should be the same if it's the same brand.

Both GM, The plug looks the same just didn't know if they pinned out differently. Thanks!