Bowtie Brody's Namesake 96 454

[Supercharged111]

Not likely. If you can swap back to black box and make some of this **** go away then there's definitely something 411 specific ******* you over.

 

[Christian Steffen]

I agree, issues don't just materialize out of thin air. If you're positive the pins are right, then I agree it's likely something tune specific.. @Mangonesailor you remember the other guy we we're working with that had a misfire issue? It was 100% tune related. Luckily he bought hp tuners, the base tune on the computer was commanding way too much timing at light load. We pulled it back a few degrees and the misfire went away. I'm wondering if this is the same issue..

 

[BNielsen]

I'll try to post a video in a little while of the truck idling as well as show some of the data on my scanner in real time,

It's gone back to wanting to stall out if I get on it too hard, I had to go jump start my brother's Suburban yesterday and it would barely idle enough to get his truck jumped off.

 

[Mangonesailor]

@Christian Steffen , Yeah, and if you Notice brody's is commanding 23* idling. (Post corrected, wrong info posted) I idle nice at 18*-ish at 770-800 RPM. I know for a fact it doesn't like more than 20 idling.

The MAF thing still puzzles me, I really want to hook up to it and look at data on the laptop.

However, I give it the benefit of the doubt that there IS something wrong. I went through the same thing with my distributor drive gear. Once the 0411 got put in I got the multiple misfire code and spent weeks troubleshooting. Finally nabbed it. I doubt he has an actual issue with his MAF, but the possibility exists... I just don't have any data to go by as far as anyone else having the issue.

 

[BNielsen]

Could the timing issues relate to the MAF reading wrong? I'm not sure how all the tuning/programming runs in line but maybe because the computer isn't getting the correct reading it's bumping timing to accommodate fuel and air?
I could be completely wrong, like I said it don't know how all this works. That's the whole reason I did this damn swap was so I could learn.

 

[AK49BWL]

The MAF reading wrong will affect fueling, which probably accounts for the +10% LTFTs - you need a new MAF curve most likely, but it could also be due to a dirty MAF sensor - I'll have more when I get back to my computer and can actually read this thread.

 

[BNielsen]

The MAF reading wrong will affect fueling, which probably accounts for the +10% LTFTs - you need a new MAF curve most likely, but it could also be due to a dirty MAF sensor - I'll have more when I get back to my computer and can actually read this thread.

I cleaned the MAF and it didn't make any change, I was going to swap the sensor from my brother's 5.7L Suburban to see if something was wrong with mine, but never got around to it. I think @Mangonesailor said the cam position code is possibly related to the crank relearn code, he posted a couple replies up about it;

I believe the tune Lextech provides for the 7.4Ls is from a "built" 454 that has a lot more done to it.

 

[AK49BWL]

I cleaned the MAF and it didn't make any change, I was going to swap the sensor from my brother's 5.7L Suburban to see if something was wrong with mine, but never got around to it. I think @Mangonesailor said the cam position code is possibly related to the crank relearn code, he posted a couple replies up about it;

I believe the tune Lextech provides for the 7.4Ls is from a "built" 454 that has a lot more done to it.

Possible.. Can you do a relearn on the crank? Also, how does your distributor shaft gear look? If it's too badly worn, it'll throw off your CMP, and your timing.

Can you log cam offset? That should read 0 +/- 8 I think is the tolerance. Something to consider since you said this may have been a pre-existing issue. It's probably going to need a new Base Idle Airflow, which you can get by logging STIT (Short Term Idle Trim), but generally you need access to a tuner to disable the LTIT, because they'll throw off your STIT. Idle timing does probably need to be knocked down a bit as well, 23 is a bit hot for in-gear idle. 17 to 20 is about right.

By chance does your logger have bi-directional capabilities?

 

[BNielsen]

Possible.. Can you do a relearn on the crank? Also, how does your distributor shaft gear look? If it's too badly worn, it'll throw off your CMP, and your timing.

Can you log cam offset? That should read 0 +/- 8 I think is the tolerance. Something to consider since you said this may have been a pre-existing issue. It's probably going to need a new Base Idle Airflow, which you can get by logging STIT (Short Term Idle Trim), but generally you need access to a tuner to disable the LTIT, because they'll throw off your STIT. Idle timing does probably need to be knocked down a bit as well, 23 is a bit hot for in-gear idle. 17 to 20 is about right.

By chance does your logger have bi-directional capabilities?

All I've got is that cheapie HF scanner, no real data-logging capabilities, @Mangonesailor is going to try and give me a hand next weekend if he's able to, hopefully he can reset the crank position, and check all that. Maybe even try to adjust a couple things, but like I said, that's all a possibility right now.
I was planning on having the distributor replaced once I get the truck running and driving, 22 years and 165K, I'd assume the shaft is a little worn, especially given the truck's use (pulling campers almost all it's life until I bought it)
Like I said I plan on de-pinning it and taking my time, remarking and double checking each wire again, maybe there is something I'm missing.

I do remember a while back when I first bought the truck, after I picked it up from my mechanic after having injectors done he said he noticed something off about the MAF readings on his Tech II scanner, I don't remember the exacts but he said it was odd.

 

[AK49BWL]

Well I notice you disconnected the MAF and it ran the same - when you disconnect the MAF, the PCM falls back to values in the Volumetric Efficiency table to adjust fueling - this is actually how you want to tune for base fueling, before you even get the MAF set up (because the MAF values will end up being based on the VE once properly set up), but generally you just turn the MAF off in the tune rather than unplugging it... ANYWAY (I have a tendency to go off on tangents), since it ran the same MAF off as MAF on, I'm kind of thinking the MAF isn't your only problem... You probably do need to tune VE with the MAF off for a bit too lol. If you were nearby, I'd put you on my HPTuners and we'd probably be able to hammer this out in a couple hours.