Complete newbie with glowing red headers at idle

[Biscuitspaw]

I may be in way over my head, but at 58 I either have to learn, or watch. So here I am. This is a new 370" lq4 with all forged internals and 11:1 Wiseco pistons Summit stage 4 N/A cam . LS7 lifters, 823 heads mild port with lighter valves and .660 PAC springs. Trunion upgrade, Trend hardened pushrods, LS9 head gaskets, ARP studs, LS3 factory intake, and still has the factory 25# injectors @ 58 psi with return fuel line. 102 DBC TB. 2000 chevrolet silverado blue/red P01? pcm. I have added a wideband , but cant get it to read other than voltage at the moment. It was idling @ 4.37V (18.74 AFR). My AEM 30-4110 gauge is maxed out at idle, and my headers glow at idle. I think I also have a timing issue at low idle that may be contributing to the glow. Any help would be greatly appreciated.

[5FDP]

You do plan to get bigger injectors right? The current injectors way too small for this engine.

Yes, timing is a problem among other things. Real low timing or negative timing can make the headers start to glow.


Get bigger injectors before you start doing a ton of tuning, otherwise you'll have to kinda start over again. Post you tune file as well.

[blindsquirrel]

The low timing is because it's trying to bring the idle speed down but there's either a vacuum leak letting too much air in, or the idle airflow table isn't letting the throttle close enough, so the only tool it has left is to pull timing. Notice that when engine speed falls it does add timing to bring it back up, but it overshoots and pulls timing again to slow it down, and then undershoots, adds timing to recover, repeat...

[blindsquirrel]

It's also dropping the MAP enough to trigger PE mode at idle, that is only making the surge worse. PE settings in the tune need to be looked at, raise the throttle threshold up to something reasonable so it can't do that anymore. It would be helpful to just be able to look at the tune file to spot things out of place that could be direct causes or contributing to problems like this.

[Biscuitspaw]

It's also dropping the MAP enough to trigger PE mode at idle, that is only making the surge worse. PE settings in the tune need to be looked at, raise the throttle threshold up to something reasonable so it can't do that anymore. It would be helpful to just be able to look at the tune file to spot things out of place that could be direct causes or contributing to problems like this.

[Biscuitspaw]

Uploaded the tune file . I'm sure I have several things messed up. I tried doing basic tuning using threads from here, youtube videos and other research. I don't think I have a vacuum leak. I have blocked off all accessory vacuum ports temporarily. I have a set of flex fuel injectors I would like to use if I can figure out how to enter the data. I do not know how to set the Iac. I also cannot get the tps to be set lower than .04%. The car will not idle below that setting . I did drill a hole in the blade of the TB. That helped some.

[blindsquirrel]

Cable or electronic TB? Your 1st post says DBW but the tune file is set to ETC = 0.

[Biscuitspaw]

Sorry. It is cable driven. I also am not running a MAF. I did add a IAT sensor to the intake. It does not have full exhaust yet. It has shorty headers with 38" of 3" exhaust. No cats, or downstream 02 sensors. I will add mufflers and turn downs at some point. I am working on getting the WB02 sensor to read AFR's through my scanner. As of now it reads only egr voltage. (May have the conversion math wrong, or something). I'll work on that more today. If it matters, this P01 is from a 2000 silverado with a 5.3 and 4l60E. I changed the parameters to 6.0L and calculated for the .030 over displacement. I have not changed to speed density tune. I am still running the stock 1 bar MAP. I am sure I am forgetting several things. Any advice would be helpful.

[Biscuitspaw]

Yes, bigger injectors are in the works. I have a set of flex fuel injectors from a 2013 L96, and a new set of Fitec 80# injectors (no injector data in packaging). I'd love to run the 80#'s but no info with them I think I can copy the GM injector info from a newer tune file. I am just a bit unsure what all info has to be transferred to my tune file.

[blindsquirrel]

If you have no MAF, and the MAF is failed in the tune (it is), then you are running speed density. That happens the same even on the stock OS. Though, if you plan to keep it MAF-less (I would, hate those things!), I would go to one of the custom OSes, as the stock OS in speed density reverts to using the low octane spark table all the time as a safety feature. The SD OS makes the spark tables work like they should again.

Here's your file with the L96 injector data - 58psi base pressure, return-style regulator, right? Let me know if it's something other than that and I can change it. (I also disabled cat over-temp, and the trans max line pressure DTCs, few other things) Copy over the changes OTHER than the injector data to your current setup, after you swap injectors copy in only the injector stuff.

current bmw 12613412.hpt

[Biscuitspaw]

It still won't idle, and is way lean at idle. The timing looks like it is crazy up and down? Headers are still glowing also.

[5FDP]

The tune has both a primary and secondary VE table. If the MAF is gone and the tune is set in speed density that means the computer completely ignores the primary VE table. So it's running off the secondary VE and that table is leaner than the primary table currently.

You need to copy over the matching rows from the primary table into the secondary table, then click smooth.

Or just apply the speed density OS, do a write entire and use just one VE. ( speed density OS removes the secondary VE table)


Also your over/underspeed spark correction tables are way to aggressive. Make it so it's -12 and +12 instead of allowing a 40 degree timing swing.

[Biscuitspaw]

If you have no MAF, and the MAF is failed in the tune (it is), then you are running speed density. That happens the same even on the stock OS. Though, if you plan to keep it MAF-less (I would, hate those things!), I would go to one of the custom OSes, as the stock OS in speed density reverts to using the low octane spark table all the time as a safety feature. The SD OS makes the spark tables work like they should again.

Here's your file with the L96 injector data - 58psi base pressure, return-style regulator, right? Let me know if it's something other than that and I can change it. (I also disabled cat over-temp, and the trans max line pressure DTCs, few other things) Copy over the changes OTHER than the injector data to your current setup, after you swap injectors copy in only the injector stuff.

current bmw 12613412.hpt

Is this injector data for my P01? I read somwhere that the math or something was different between the two. The car is still hunting and glowing red hot on the headers. I am trying to learn how to set the iac steps currently. I also am fairly convinced the lean issue is more from timing than fueling. When I accelerate, the AFR's go in the acceptable range. It is only doing the glowing when trying to idle. Also, should I just start over with a speed density only tune? Sorry, lots of questions...

[blindsquirrel]

You really, really need to add all the idle-related channels to your logs, especially IAC stuff. Right now it's impossible to tell you why it's running at 1800 RPM and 0% throttle - this is why the idle timing is low, it's trying to bring the idle speed down by pulling timing. If the IAC is wide open, then that's what needs to be fixed. But if IAC is closed and idle speed is still too high, you have to find where the extra air is coming from.

Read up on Gen3 idle tuning, see if there's a thread that lists what channels you will need to log. I am really a Gen4/ETC-only dude (if that).

The file I posted is your file with the L96 12613412 injector data imported, for when you get around to doing that.

[dhoagland]

Last post here for charts, graphs... Channel config is at beggining
https://forum.hptuners.com/showthrea...l=1#post659192

Ton of reading here, might skip to post #5. I believe with this and the configurations (channels, graphs, etc) in the above link you can be headed in the right direction soon
https://forum.hptuners.com/showthrea...e-(w-pictures)