map reading 105kpa with motor off after 2 bar os

[QUADRACER541]

When i have the stock tune flashed the map reads correctly. And when i go to the 2 bar os it reads 105 kpa without the motor running. Also the motor runs like crap unless i unplug the map sensor. Anybody else having. This problem?

[DSteck]

Check your MAP sensor calibration.

[LSxpwrdZ]

With the 2bar OS you have to actually physically change to a 2bar sensor as well. Most all stock NA LS engine cars will only read up to 105kpa.

[QUADRACER541]

i did have a 1 bar map at first. i have a true 2 bar installed and still reading 105 with key on. the sensor reads 2.5v with key on and motor off. map linear set to 200, offset to 10.33. it also has a hard time starting. once it starts it will run really well for about 5 seconds and then start surging and die.

[C Del]

What does the MAP read when the engine is running? Does it jump around or stay constant?

[QUADRACER541]

it does change when running. i cant remember what the kpa was but my other gauge is set to psi and it reads 14.8 with motor off and 6.5 when idling. my dash vac/boost gauge says 25 of vacuum when at idle

[Chris@HPTuners]

When i have the stock tune flashed the map reads correctly. And when i go to the 2 bar os it reads 105 kpa without the motor running. Also the motor runs like crap unless i unplug the map sensor. Anybody else having. This problem?

100 - 105kPa is atmospheric pressure.

[LSxpwrdZ]

Normally to get that map sensor to read correctly with the current weather stations barometric pressure I use 8.8kpa and 200kpa. Generally barometric pressure stays between 98-99 here in central Kentucky. Few days when a high pressure front comes through we will see 101kpa.

Best thing to do is double check how it reads with a weather station. You can convert inHG to kpa using a convertion calculator.

[QUADRACER541]

Ok that makes sense. Thanks for all The help. My next problem is the motor Surging and dies. i'm pretty sure it's my injector calibration. I Have venom 48# injectors for a 86-04 corvette from ebay ( big mistake). They came with a basic flow sheet. But no calibration info. And no response from customer service.