I just finished a HG job, and while I had the intake runner off I broke the boost sensor. Now that the job is finished, the boost sensor that I replaced it with is reading wrong and reads way above atmospheric with the key on and engine off. The first sensor I put in was brand new and it did not come off 255kpa ever. I thought the sensor was bad so I put one off a not running duramax and now this happens --> It reads 186kpa, voltage at roughly 2.3v. I know the pressure is wrong, but is the voltage right for atmospheric? I'm wondering what I need to do to make this thing right again. Do new sensors or even sensors put on different applications need to be rescaled? Any help is appreciated...
Boost Sensor Screwed?
- Thread starter FTGdMax
- Start date
Yes grounds attached, but I'll triple check. What's strange is when I get on the throttle, the voltage for the sensor goes down, not up. Anyone had this happen?
So here's the exact numbers. With key on, engine off the barometer reads 100kpa, and the map sensor reads 185kpa, or 26psi. This comes with a voltage of 2.29v. When I start it and get on the throttle the pressure actually goes down to about 170kpa with a voltage of roughly 2.15v. HELPS
Disregard everything from above. This is an update on the situation...
Ok here are the issues, and the things I know for sure.
My map sensor is reading incorrectly. The sensor reads 185kpa, or 26psi. I saw one other post on here about this issue, but it was from 2012 and no one has responded to it.
Bad sensor?
- I know the sensor is good. If you swap it to the baro sensor location it reads correctly.
Voltage or bad ground in map sensor location you say?
- Voltage coming from the sensor is 2.29v, exactly the same as baro sensor. The baro sensor reads correct at 100kpa. Also, the source is an exact 5.01v.
Those things being said, my idea is that maybe the computer is misinterpreting the voltage value? Has this happened to anyone? Maybe I need to flash back to stock and then retune?
This is causing my motor to think it has too much boost and open the vanes waaaaayyyy too much, like 9%. How am I supposed to build boost like that??? I'm not. So this needs to be fixed.
All of this was read with key on engine off
Ok here are the issues, and the things I know for sure.
My map sensor is reading incorrectly. The sensor reads 185kpa, or 26psi. I saw one other post on here about this issue, but it was from 2012 and no one has responded to it.
Bad sensor?
- I know the sensor is good. If you swap it to the baro sensor location it reads correctly.
Voltage or bad ground in map sensor location you say?
- Voltage coming from the sensor is 2.29v, exactly the same as baro sensor. The baro sensor reads correct at 100kpa. Also, the source is an exact 5.01v.
Those things being said, my idea is that maybe the computer is misinterpreting the voltage value? Has this happened to anyone? Maybe I need to flash back to stock and then retune?
This is causing my motor to think it has too much boost and open the vanes waaaaayyyy too much, like 9%. How am I supposed to build boost like that??? I'm not. So this needs to be fixed.
All of this was read with key on engine off
There's your problem. The baro sensor and MAP sensor are not the same.
You have the wrong part number as your MAP sensor. I learned that the hard way too. Also, brace yourself for the price of the MAP sensor
There's your problem. The baro sensor and MAP sensor are not the same.
You have the wrong part number as your MAP sensor. I learned that the hard way too. Also, brace yourself for the price of the MAP sensor
I've been told they're the same, each has 5v and should read the same variable voltage with the engine off because they're both reading atmospheric. If this is the case do you have a part number for the MAP sensor for the LLY
This would make sense though, because after I broke the original sensor, I bought a cheapy. It didn't work at all so I robbed a baro sensor off an LB7 because I was told that baro and map sensors were the same. This is the sensor that reads right in the baro spot but not the map spot. Also, my original baro sensor (which is fine) works right in its spot but not the map spot.
There's your problem. The baro sensor and MAP sensor are not the same.
You have the wrong part number as your MAP sensor. I learned that the hard way too. Also, brace yourself for the price of the MAP sensor
The two sensors do in fact have different part numbers. Part number for MAP sensor (ACDelco) is 12623671. It's shown by the stealership as a turbo boost sensor. We will see this weekend if this fixes my problem.
Well, after putting in the new MAP sensor, everything is right in the world.
Now a completely different and not related problem is I have an injector return line that keeps popping out of the #7 injector. Should I just replace the return line fitting and clip?
Now a completely different and not related problem is I have an injector return line that keeps popping out of the #7 injector. Should I just replace the return line fitting and clip?