Do these numbers look right?

[Ed Wright]

As Chad said, put an extension on the collectors for idle & part throttle. Unless you have had eight wide bands in the primary tubes to verify all eight cylinders are equal (they never are unless it has been put into sequential mode for cylinder-to-cylinder tuning) putting one upstream may or may not be accurate. Ten percent variation between cylinders is not unusual. At WOT, using one upstream, your indicated 13-1 a/f could be 12-1 or 14-1 on most other cylinders. EGT is not an accurate indicator either. Things other that air/fuel effect EGTs. Most agree that the average you see in the collector is best indicator if individual cylinder-to -cylinder tuning has not been done. Don't tie yourself into some magic number, find the air/fuel ratio makes your car run the best MPH numbers. Don't worry about what somebody else's car likes. Cars I have worked with like somewhere between 12.5-1 and 13.25-1 @ WOT. Mine likes about 14-1 idling & on the return road, with extensions on the headers, it's always in open loop.
Me tuning extensions are 3' long, with a 45 deg bend in the middle.
Your results might vary. LOL

[Signman]

When my O2 sensor went bad it made the car run really rich, hey don't like to be knocked around.
Try a new sensor along with the other good advise above.

[Bobby Fazio]

But wouldn't "open loop" behave as though there is no o2 sensor connected? It all comes down to MAP sensor and Intake Temperatures, correct? Is there anyone I could possibly send the DFI box to for checking? I feel there might be something internal going on.

[Ed Wright]

Open loop ignores the O2 sensors. Used only for a tuning reference when logging runs.

[buzzinhalfdozen]

Ok, Bobby how bout this. Where is your MAP located..in the ECU or out, in either case why don't you try this. Disconnect the vacuum hose from the engine that hooks to your MAP sensor install a hand operated vacuum pump and pull a vacuum on sensor to around 40ish PKA see how your Pulse width responds, it should go down. Looks like the MAP is very high in the idle shot you posted, other than that and the fact your P.W. looks extremely high the rest looks normal to me. Another check is to use your vacuum pump and pull a vacuum...read the gage (on the pump) and see if it is close to what your ECU is reading. this should tell you if the MAP is skewed or not. Please try this if you can and let us know the results. Not knowing your set up (engine size, injectors cam, ect.) I'm merely guessing but I'd expect to see maybe 2.9-3.? M.S. of pulse width at idle. Again good luck. Joe, Bobby I also noticed you have nearly 2 volts difference in batt. voltage. Though I don't believe that is causing the issue you have you need to be aware that voltage has a direct effect on the injector "on time" just something to think about. On another note does your ECU have any type of "blending function" to blend between the TPS and the MAP sensor to correct for poor MAP signal @ idle?

[buzzinhalfdozen]

Bobby, if you can please try the test I described using a hand held vacuum pump as I'm quite certain the MAP input you're seeing at idle is the cause of your rich fuel mixture. Please try and see if the gage and your MAP reading on the laptop agree while applying vacuum to it...you can do that with the engine off. If they are off by a wide margin then there you go, if not then please post up the results of bringing the MAP to around 40ish with the engine running and see if your pulse width number decreases. Joe

[Ed Wright]

I can't read his gauges on my phone.
My raggedy-azzed junk idles about 65 KPA.

[Dave Noll]

It show's -1.9 psi @ idle & -6 @ 2500. Your 65 KPa @ idle converts to -9.5 psi. On the scanner I used to use it would show an actual O2 reading & a light would come on showing when it went into closed loop. Does this software do that ?

[Bobby Fazio]

Originally Posted by buzzinhalfdozen

Bobby, if you can please try the test I described using a hand held vacuum pump as I'm quite certain the MAP input you're seeing at idle is the cause of your rich fuel mixture. Please try and see if the gage and your MAP reading on the laptop agree while applying vacuum to it...you can do that with the engine off. If they are off by a wide margin then there you go, if not then please post up the results of bringing the MAP to around 40ish with the engine running and see if your pulse width number decreases. Joe

I'm confused because a conversion table says says 86kpa is 12psi so why am I idling at -2 psi? Anyways my vacuum pump is inHg.. so now I have to convert that also.

[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?