Tuning help needed - '91 TBI 383 w/ Vortec heads

[donf]

I have my sensor wired into the ecm. The instructions are the same for logging even though there is no gauge. Its important that you download the zip and follow ALL the instructions. I have had several people here contact me privately saying their wide band is not working. I ask them to follow the instructions listed in the zip file and never hear from them again. Ha ha. I think people just think its hooking up a wire and your done. I also had to redo some of the adx file. The A217 OD file has some quirks. Some stuff led me to change things and now I like it better. One peeve is they have extra data points that look cool for the fuel table but have no value as the bin does not have those same points. I kept getting data from the useless columns/cells mixed up with the ones I needed. Now my ADX does not have those!

[Daveo91]

I have my sensor wired into the ecm. The instructions are the same for logging even though there is no gauge. Its important that you download the zip and follow ALL the instructions. I have had several people here contact me privately saying their wide band is not working. I ask them to follow the instructions listed in the zip file and never hear from them again. Ha ha. I think people just think its hooking up a wire and your done. I also had to redo some of the adx file. The A217 OD file has some quirks. Some stuff led me to change things and now I like it better. One peeve is they have extra data points that look cool for the fuel table but have no value as the bin does not have those same points. I kept getting data from the useless columns/cells mixed up with the ones I needed. Now my ADX does not have those!

Thanks for the great info. Unfortunately, my project has hit a major mechanical stumbling block - my new 383 seems to be using significant oil. And it's not going on the ground. The only explanation I have is that I have the wrong oil rings or they didn't seat correctly. I haven't talked to the machinist yet that did the work (I assembled) but I'm guessing I'm going to have to pull the motor and tear it down. Obviously tuning will go on hold if all this is accurate.

[donf]

Thanks for the great info. Unfortunately, my project has hit a major mechanical stumbling block - my new 383 seems to be using significant oil. And it's not going on the ground. The only explanation I have is that I have the wrong oil rings or they didn't seat correctly. I haven't talked to the machinist yet that did the work (I assembled) but I'm guessing I'm going to have to pull the motor and tear it down. Obviously tuning will go on hold if all this is accurate.

Thats too bad. It has to be disappointing.

[PlayingWithTBI]

Bummer - hope it's something simple like the rings' gaps lined up in a row vertically (I've seen it before).

[Daveo91]

Bummer - hope it's something simple like the rings' gaps lined up in a row vertically (I've seen it before).

Thanks to both of you. Yeah, I’ve been hoping for something simple for a while now, have actually been in denial. But I can’t deny 1/3 to 1/2 quart in 300 miles any longer. Funny thing is plugs do not look oil fouled to me at all, and the (hot) compression is good and consistent in all cylinders (approx 180 at three hits and 200-210 at five hits). And there are not clouds of smoke going down the road, even when I get on it with high load. It will puff smoke if I gun it at idle, though.

As for ring install, I followed the instructions that came with the Hastings rings to a T. There’s a backstory tho: I had to switch machinists mid-build. The first one was hitting the sauce pretty hard and he had about five missed deadlines. He also bought pistons that would have given me 10:1 CR with vortec heads. So I found a new machinist and bought some KB pistons that lower my CR half a point. Second guy, who has a good rep building high end motors, said the rings would be fine with the new pistons but now I have some doubts.
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[donf]

Some rings take a different grit hone. Its possible if between the two machinists, the wrong grit was used the rings may take longer to seat or may not seat at all. The plugs look really good, so not a lot of oil is getting in there. I made the mistake of ordering Jegs crappy vortec heads, the guide seals leak even with under a 1000 miles on them. i will have to tear them down this winter.

[Daveo91]

Some rings take a different grit hone. Its possible if between the two machinists, the wrong grit was used the rings may take longer to seat or may not seat at all. The plugs look really good, so not a lot of oil is getting in there. I made the mistake of ordering Jegs crappy vortec heads, the guide seals leak even with under a 1000 miles on them. i will have to tear them down this winter.

Thanks for the info. I know there was something with the hone. The first guy did his own, but I know the final machinist did a cross-hatch hone too. He didn’t want to rely on the other guy’s work. I’m going to change the oil one more time and see if that helps. Initial start up and first few hundred miles were on conventional oil (Chevron Delo, I think) but then I went to Mobil 1 synthetic. Sounds like there’s at least a possibility that’s making things worse. I’m going back to probably Shell Rotella, put a couple hundred miles on it and see if there’s improvement. Also ordered a new AC Delco PCV valve tonight - just in case the parts store one in there now is adding to the problem.