Error when calculating psi/vacuum, kpa is correct

For discussion of Phil Tobin's Tuner Studio software (Only about the tuning software itself, not about how to tune or firmware features)

Moderator: LT401Vette

Post Reply
pimpsmurf
MS/Extra Newbie
Posts: 10
Joined: Thu Oct 02, 2008 12:12 pm

Error when calculating psi/vacuum, kpa is correct

Post by pimpsmurf »

Somehow I've managed to hose my installation. In an attempt of not starting my msq over from scratch, I figured I would bother you guys for a minute.

First, my KPA works perfectly. It shows around 30-39kpa at idle, which is normal, (depending on electrical load.)

I am hitting around 132kpa in boost (back to low boost until I fix a couple problems.)

Unfortunately, the calculations for psi/vacuum are all off. It shows 2psi at cruise (around 50-60kpa I believe) and only 10 inHg at idle, which is really around 16-18 I believe.

I have set the normal ambient pressure to 100kpa, which is what I typically see, but still no luck. It happened when I flashed the MS box with a MegaLogViewer-generated MSQ, and I didn't notice it until it was too late.

I would really love to have a digital boost gauge, so if anyone can recommend something to try, please let me know!

thank you,
-JNY
pimpsmurf
MS/Extra Newbie
Posts: 10
Joined: Thu Oct 02, 2008 12:12 pm

Re: Error when calculating psi/vacuum, kpa is correct

Post by pimpsmurf »

The KPA is correct... so was the vacuum. I'm a moron. I unplugged the boost solenoid and forgot to plug the hose until I can get the new one installed. :(

Sorry for the disturbance, move along! haha

What confused me is that the different between 33kpa and 39kpa is 19inHg to 10inHg. A little leak can go a long way apparently.
LT401Vette
Super MS/Extra'er
Posts: 12697
Joined: Sat Jul 16, 2005 8:07 am
Location: Moorseville, NC
Contact:

Re: Error when calculating psi/vacuum, kpa is correct

Post by LT401Vette »

No worries... If it confused you, you can rest assured it confused a thousand others.

But I must please emphasize to all...
It is often though that you need to create a new msq, but that is completely not true!!!!

Even if you do create a new msq file, the first thing TunerStudio does when it connects to your controller is read the values from it. It doesn't matter what you have done in an offline msq, the controller is always right. Any time you save an msq while connected to the controller it will contain the values that are in the controller, all of them.

I really need to get this info in to help files, but it is much more preferred that it works as you expect the first time, so all suggestions are always welcome.
Phil Tobin
EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
Post Reply