Tune goes richer than LHM when cold

[1BadAction]

When the truck is up to temp, intake warm, oil warm, and 70 degrees ambient, the BLMs run between 125 and 132ish, runs like a top and lights off immediately. When it's roughly 40 degrees or colder, however, is where things go south. The tune goes so rich, black smoke is blowing from the exhaust and it's backfiring, etc. It's pure insanity. In this situation today after work, by pure accident I found out that limp home mode actually runs better than what this tune is doing, the truck will actually run ok and warm up in LMH. I'm at a loss here, can you guys take a look at this and tell me what I'm missing please? I tried to get a log of when this happens but it doesn't really stay running enough to get one that's worth anything. I have attached a log of when the truck was up to operating temp and getting the final numbers for my VE table this weekend.

Here's a vid of warm restart.
http://youtu.be/53dLlhWmmmY

Attached are the tune, running at temp log, and XDF/ADX.

PLEASE DO NOT DISTRIBUTE this XDF, it's still a work in progress. Thanks!

[EagleMark]

Two ideas...

"Cold engine AFR vs Coolant Temp."

Or to much spark with Spark Advance Table and Cold start spark adders causing a misfire... which will do all sorts of nasty things to MAP or O2 sensor if CL.

[1BadAction]

Two ideas...

"Cold engine AFR vs Coolant Temp."

Or to much spark with Spark Advance Table and Cold start spark adders causing a misfire... which will do all sorts of nasty things to MAP or O2 sensor if CL.

I fiddled with the cold engine vs coolant temp without much success. The cold start spark adders were turned up slightly though (I don't remember when I did it) So I put them back to stock. I will try as it is now, but looking at that spark table, it is roughly in the same temp and vac that I'm starting to have issues in. I may even need to turn the wick down from stock in that table considering how aggressive my main spark table is.

[1BadAction]

Also, does that log look normal to you? I find the data seems a bit jumpy at times but it might be that I'm used to EFILive. The O2 is all over the place but it's a bosch... Would be nice if the ebay seller decides to send my heated NGK out that I paid for 10 days ago.

[EagleMark]

Log looked great to me.

Sometimes $85 get's a glitch.

O2 sensor should be all over the place with cross counts when CL.

[1BadAction]

Well Mark, that is surely what it was. I put the "Cold start spark added vs Vacuum" table back to stock this morning and I watched closely as I cranked it up. There must be some other spark multiplier at work because right after it fired the timing shot up over 34 degrees (actual) from 22 and it started violently pulling timing then adding it back in. I shut it off and zero'd out that table, had to do the foot to the floor maneuver to clear the flood, it then stabilized and started to idle ok at 22 degrees of timing. Shut it off and started it a third time and it seemed like it was fine. So, in the Cold start spark added vs Vacuum table is what is causing my problem, the higher compression must not need nearly as much additional timing when it's cold out.


After yesterday the truck seems like it's not running quite as good so I'm wondering how many plugs that I blew the tips off of yesterday when I was fighting this thing to get it to run

[EagleMark]

After those issues I would replace a set of plugs! Still inspect the old ones to see issues.

I use a magnifying glass to look for issues like specs (flying turds) but usually can see them if bad by eye. If you can do good clear close up of plugs I'll try to read them.

[1BadAction]

Glanced a few times at the log file yesterday on the drive home and my TPS voltage at idle was moving around from .51 to .60, which is why it was acting a bit strange. Checked the screws this morning and they were snug but not tight, so I clamped them down. If they loosen up again I'll blue loctite them. Also pulled the #1 plug and it looked fine to me, no broken tip, no insulator cracking, and the mix looked maybe a hair rich but not really bad at all. They are pretty cold, NGK UR6ix, so that may be contributing to the way they look. I'll probably end up putting the Delco R43TS plugs back in it this weekend...

[billygraves]

................

[EagleMark]

TPS could be just worn out and if you get a voltage glitch, not movement, it will cause all sorts of issues. This can also happen when a throttle blade shaft is worn, sometimes it closes all the way and sometimes sticks a little.

That's a cool tip from billygraves on the plugs! I'm going to see if I can get a set. I do not like any specialty aftermarket snake oil type better then original more power and better fuel milage type plug!!! All I've ever seen from them is issues! If not as soon as you put them in? Soon... I've fixed a lot of weird issues by just putting stock plugs back in.

Stock plugs in copper, Iridium or titamium or whatever? They are all the same and precious metals just last longer. May change heat range but that's it. Stock from OE is always the best.

[billygraves]

......................

[EagleMark]

International Harvester had a Service bulletin and package to re-route IIRC 5 and 7 plug wires when scouts came out with electronic ignition. They were loosing cylinders from detonation damage!

Yet I still see some guys cable tying their spark plug wires together...

[1BadAction]

Well I haven't had any more issues after reducing that added spark when cold down to 20% of what it was originally. The TPS was just loose, it hasn't moved around any since I tightened it down.

As far as plugs go, I like my NGKs. UR5 and UR6 are a proven plug in BBCs, and NGK plugs as a whole work excellent whatever I've used them in, including other TBI/TPI vehicles. The metal plating they use also makes the fuel mixture easy to read, which is nice. I wouldn't run a champion in a lawnmower. That said, Delcos are cheap and you can't go wrong with them in a GM. My truck is almost 2 full points of compression higher than stock, so we'll see how a stock heat range plug (CR43TS in this case) works. If I have heat issues this summer with the 3 heat range delco I can step one colder to the 2 and still be able to get them anywhere. I have a feeling that in another 20 thousand miles with this truck I'll have a built 8.1 vortec for a swap anyways, so the longer life of the NGKs would be a waste in this instance.

I'm a bit of a neat freak when it comes to plugs and wires (although I still haven't tidied up some of the other looming yet), 5 and 7 are spaced on opposite ends of a plastic clamp separator at the back of the engine.

[1BadAction]

BTW, that iron intake is a bitch to get warmed up even with the factory heat tube. I think the next major thing I do is swap to a bored out edelbrock and a JimD TB. Truck just runs so damn good I hate to have it down for any length of time.