Do these numbers look right?

[buzzinhalfdozen]

I'm afraid I can't help with the conversion however I do know that on a properly functioning engine (stock) I'll see between 35-40 KPA at idle. With the larger overlaps in the race cams that signal very diminished...which is what you're seeing. Looking at your 2 screen shots you can see when you rev it up the vacuum gets much better and the KPA number goes down, also your pulse width goes lower (less fuel) indicating to me that with the MAP reading it's providing @ idle the ECU "thinks the engine is being loaded, hence the increase in fuel. Have you checked to see what the MAP shows with the engine off? Also it looks like you have a display of vacuum on the screen, though I'm unsure of the exact scale they are using. Have you tried using the vacuum pump to decrease your MAP down to a lower number and see if it improves your fuel rate? Last question...when it was tuned by your tuner did it behave in this manner?

[Dave Noll]

The control panel of the software show's almost all the conversion you need. The dial to the left of the tach & above battery voltage show's vacuum in PSI. The small box below the voltage dial, third from the left, is vacuum in KPA. To convert PSI to inches of vacuum, multiply by 2. (-15 psi is 30" of vacuum, -2 psi is 4" of vacuum)

[buzzinhalfdozen]

Dave, good info, I've honestly never thought of the conversion as I've become accustomed to using only the KPA reading. BTW Bobby have you any news regarding your tune and the possibilty of blending the MAP and TPS in the lower cells?

[Bobby Fazio]

MAP sensor is fine. I emailed the saved tune to my tuner and he and I went through it over phone and said all looked well with no weird numbers. So I decided to do a third compression check and number 8 was a little iffy for the first time, why it wasn't before bothers me but I did this one cold before ever starting the car. Pulled the head off and the intake valve is bent. Hit the piston when the rocker had loosened up on that last pass. No real damage to the piston thankfully. So now I feel like a complete idiot and this is what I get for trying to do all this without the help of my dad because I want to learn this stuff on my own. I'm hoping that this caused the over-fueling by tricking the MAP sensor into thinking the engine was under load since number 8 wasn't firing correctly? If not then I still have another issue. I will find out when I get the head back and put it back together. Thanks for your help.

[Angelo DiTocco]

Originally Posted by Bobby Fazio

One screenshot is car idling, the other is at 2500 rpms. Still running rich as hell. I am out of things to check and not familiar enough with DFI to change anything internal.

Bobby - what combo is the system on? a race car? let me know.
what is it doing - loading up and stalling?

3 quick things
1 - an 02 sensor won't be hot enough to work correctly or read accurately at idle (unless it has a pre-heating element in it - some do, some don't) so tuning a car at idle is trial and error.
2 - your coolant temp is 80 degrees - it could be running rich because it thinks its in warm-up mode - faulty temp sensors can do that too - they are cheap I'd change that as well.
3 - i dont know what your running it on but sometimes the throttle blades need to be opened up and the TPS reposition to read right.

b

[buzzinhalfdozen]

Bobby, first don't beat yourself up over it, learning new things can be a daunting task, second it makes perfect sense that the intake valve being bent was allowing pressure back into the intake manifold throwing your MAP reading out in left field. Congrats on finding it and please let us know how it runs after the repair. Joe

[art leong]

Don't know if this will help. But some tuners aren't concerned with low rpms, just horsepower and torque. I brought my car home from a dyno tune a couple of years ago. And it was so rich my eyes were tearing when I put the car in the trailer. I then tried to tune it down low. And made it worse. I went to the track and tried to tune the leave and slowed it up half a second. My plugs would get sooty black driving around the pits. Tried changing plugs, wires etc. No help.
Then I thought about it a while. I was leaving with a 2 step. Which I thought would make it rich, because it wasn't burning fuel in 1/4 of the holes. Then it dawned on me that it is an "Oxygen" sensor not an unburnt fuel sensor. Also I found that below 4000 rpms my wide band O2 sensor in the collector was useless (unless I put a 3' extension on it).
I put in an upstream O2 sensor about 14" from the valve. I use that to tune low rpms. When leaving using the 2 step I just try one thing or another and if it picks up I try a little more till it slows. If it slows right away I go the other way. 99% of the time I have dead hook so no variables there.