Got some powerlogger data thats needs a look at

[JDEstill]

To muddy the waters a little, here is another file. Same settings on everything as in the first file, but this time I asked Brian to drop the fuel pressure, as he had it set higher than recommended (understandable due to the severe lean condition seen at idle). We did not drive the car like this, only sat and idled it. Well, not totally true, I had him give it a little gas for a while, but the whole last half of the file it is just idling. The idle BLM did a flip and went screaming upwards, but as the log ends, it was somewhat still in control, the O2s are moving around still. Maybe we needed to set it at an intermediate pressure and then go for a drive and let everything learn and see what that resulted in.

I should mention that he does have a wide band. We didn't have time to get it hooked up to my PL, so it isn't logged, but when the NB reads lean, the WB reads lean; when the NB reads rich, the WB also reads rich. At the end of file A, when the NB is showing 0.050 volts, the WB was showing a/f ratios of 17+. I didn't *see* any problems with what the O2 sensor was saying just based on watching the WB gauge. Of course, super easy to miss something without it being logged.

Eric, if you can give us a setup you'd like to see logged, I'll run over there and log it and post it, and maybe we can trial and error our way to a solution.

John

 

[Eric Stage I]

What was the fuel pressure, and what is it now? It looks like the BLM responded to the change. I would reset the ECM and drive around.

For the idle BLM, it sure looks like an air leak somewhere, maybe PCV valve? Might try to block it off temporarily. I normally expect the BLM to drop a few numbers when blocking PCV, but if it drops like 10-20 numbers, then it might be flowing too much air.

But for now, as an easy change, I would go to the "MAF Sensor Tune/Flow" page in the Gen2, and add fuel in the low gr/sec area. Add like 20% in the 4 to 8 gr/sec area, and blend it out above that. That should bring the idle BLM down closer to the others, and help the oscillating idle.

 

[GBGN1]

Ive already blocked off pcv and didnt see really any change. Sprayed carb spray everywhere-Its got a brand new RJC pcv. Ive plugged off every vacuum source I could find. Still have the same problem. Its not constistant, for no aparent reason it will just dive(blm). I dont know a vacuum source that comes and goes like that. Idling not even giving it gas it will do it.

Ive already added fuel on the low rpm side tune with no good results. Ill go into the maf sensor tune and add some there.

 

[slimtastic]

sounds like its dong the inverse of what it should be doing (going lean=pull more fuel out!)

toss a classic fast/xfi/bs3 on it... you've got enough money in the motor that a proper stand alone is just another drop in the bucket

 

[GBGN1]

I don't have a smoke machine. Could I just take off the rockers and charge one of the vacuum taps on top of the throttle body and plug the rest. With a few pounds of pressure I should be able to hear a leak?


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[slimtastic]

You could try that but the iac/tv will still be slightly open causing alot of noise, so you'd have to use a stethascope with the metal end removed and listen down the pushrod holes

 

[JDEstill]

Had a Gen II question that came up while looking over Brian's set up. Why is engine displacement one of the entries? I thought this thing was primarily just translating various MAF sensor signals into something the ecm can read. If using the Gen II to go richer or leaner, it should just do that as a % of the signal. Where does engine displacement come into any of this stuff?

John

 

[TurboBob]

it is used to scale "load" into units that approximate a MAP reading, it is not used in any of the fuel calculations, but in selecting which adjustment is active.

It is not a critical adjustment.

Bob