Okay here is my information, I have a 355 cid motor with ~9.0 :1 compression, comp cam .480 lift I&E and duration of 224 and 230, I dont remember the part#, but it is the largest cam you can get for computer controlled engines, 1.6:1 rockers, SDPC Vortec heads, Holley Stealth ram with Holley 58mm TB, shorty headers, full exhaust with cat and I am using the 165 ECM with MAF. I am using the $6E mask and TunerProRT to edit my chips. I will try to post a clip of my data logging showing where the trouble is.

Now for my question(s), I have read as many DIY Prom articles as possible and I have a rough understanding of what different things do, but have not been able to find the information that I need to get going, oh and I need to add that I pulled the screens out of the MAF sensor (dont know if that was the right thing to do), the other "mistake" I made was I purchased a Bosch O2 sensor, I know you dont have to say it, BIG MISTAKE! The O2 is indicating that I am running really rich 800+ mV at idle, but the plugs say I am running lean, so lean in fact I melted some of the wire loom under the hood, and turned the flowmaster muffler a pewter color, it ran like that for only about 2 minutes, but wow did it get hot! I need a little help, a "push" start on how to tune the MAF tables or whatever I need to tune to help richen up the idle, and I know that to really tune the car right I need a WBO2, but that will have to come later, I got a little girl on the way!! All help, comments, jokes, and anything else will be appreciated.

 

I don't think you can run lean enough to get the muffler hot at idle. But if your were way rich and put some fuel into the exh with retarded timing......
Burnt wires will put some fuel into the exh.
2 minutes isn't enough to color the plugs I'd think except down by the base of the center electrode.

I'm not a MAF user. But from what I've read.
You'd be better off getting it running well with the screens in first. Then pulling them if desired.

 

Thanks for the input Z69, I am still searching for someone else with similar problems, I think I am getting closer to a solution. Do you think that the bosch O2 sensor could possibly be the culprit of some of my problems?

 

What is your idle rpm and cam overlap? I was showing lean at factory idle speeds after my mods. Through research on here and testing different changes, I found that my cam overlap may have been introducing fresh O2 into the spent exhaust stream making the O2 show lean and causing more fuel to be added by the ECM. I raised the rpm a bit at idle for the lumpy cam and O2 numbers came right in. One huge hint that should help is if the blm's come into range at a slightly higher idle before you change any maf adjustments. Try logging in closed loop while holding th idle at 700, 800, 900, and 1000. Look at the data. You can expect to have blm's and int's off 128 after de-screening the maf, but the situation you describe shouldn't take you to blm's of 160. I'm currently running an 800 rpm idle. One thing that does stick out about your post is that you say your car only ran for a couple minutes. The ecm waits 300 seconds for the O2 and engine to warm up before it goes into closed loop. If you only ran for a couple of minutes, the O2 readings are probably not accurate and the ecm wasn't making any corrections for O2 output. I'm by no means a pro at all this stuff, but I have been working with logging and tuning on a similar application to yours for about 8 months. I've learned a ton by trying small subtle changes at first, being careful not to go overboard.

 

My cam has an overlap of 45* and I have the idle rpm at 800 in park and about 750 in Drive or Reverse. Maybe I wasnt clear on what the datalog showed. My O2 mV were 800+ and my BLM finally bottomed out at 108. both indicating I was rich, but the plugs looked if anything a little lean. I am going to do some more test driving and datalogging. I believe my problem lies in my MAF tables. Oh and by the way I got my car emission tested today and it passed with flying colors even with the BLM being where it was (114).
I will attach the emission documentation. Thanks for sharing your experience.

 

here is the emission testing results.

 

Your cam has 45 deg. of overlap? No.... that can't be right. What cam is it?

 

It is a Comp Cams XE268H
Lift Int.=.477 Exh=.480
Dur Int=224 Exh=230
Lobe seperation of 114.0

I used the overlap calculator on http://www.wallaceracing.com/Calculators.htm

 

If your intake opens at 24 deg. BTDC and your exhaust closes at 22 deg. BTDC doesn't that mean that the cam has 2 deg. of overlap?

 

Not normally, it looks to be a typo for the BTDC. EC & IO- add them together. 24 +22 =46.
If the IO is ATDC, then you subtract.

 

I totally misread the post I responded to. I apologize. I've been using a wideband too long. LOL Ok, down to business....your O2 says your rich and your plugs say your lean. Hmmmm......how do you get your O2 voltage readings? I gather you are datalogging. Is that right? If you are, what are your injector pulse widths at what rpm and maf at idle? What size injectors did you put on this engine? I'm sure the answer is there, we just have to dig. Hope I can help.

 

First off thanks for continuing to respond, I know most people probably get tired of asking these same questions over and over. In answer to your question I do datalog, and it is with tunerproRT (awesome program!). As for the other data I will have to get back to you on that, haven't really payed attention to the pulse widths. I can tell you for sure I am using LT1 24# injectors and that is what I tune the chip for. If it helps I am using the ARAP bin with Injector const. at 24#, I changed the Idle vs. Coolant temp, and disabled the egr. Also as if that wasnt enough I went to an 1/8 mile track tonight, (the track is only about 5 mi. from me, very convinient for me!) and the best time I could pull (with 2.73 one legger rear end) was a 9.22 at ~76 mi/hr, dont quote me on the mi/hr. Everything felt alright, I was just hoping to get in the high 8's first time out. OH well! I still have to look over the data from the 1/8 mi, I have about 3 runs on datalog. Funny thing is on that first run I believe I pegged out the MAF, because later I checked the computer and it told me I had MAF err high, or whatever it says. Thanks againg for your response and help.

 

I don't think you can post someone's signature without their permission.......so I would remove that.

Overlap can be speced relative to .050" or the cam manufacturers low lift value. At .050" it appears to have -1* overlap. The lift spec is where all the confusion came in.......see it in a lot of posts.