Frustrating Idle Issue

[BagD72Chevy]

I am having problems with my truck idling and it is driving me crazy. This is the first tune I have ever done using efilive. The engine is a sbc with an LT1 intake, vortec distributor, and 0411 PCM. The cam is around a 218/224 110-112 LSA .450 lift. I'm running a modified van tune with a camaro trans module. The truck has been running great for awhile, except for a stumble when I would go to take off from a stop and it idled extremely rich. 11.8-12.1 on the WB. I started to fix this and I realised I was in open loop. I went to closed loop and have been working on the tune and this is where I'm at. I added timing in the 400-800 RPM range to help as a stall saver. When I start the truck it will idle very smooth for 5-10 sec and die. There is nothing I can do with the accelerator pedal to keep it from stalling. I attached a log and the tune if someone could give me hand. I can also run another log if I dont have the correct PID's chosen. I did not have the WB connected because I loaned it to my brother.

Thanks in advance, Ryan.

[ScarabEpic22]

First off, there's some weird data in that tune. The Main VE table is all sorts of messed up, you need to redo it. Looks like it was copy/pasted from a Calc.VET or AutoVE log without any correction/filtering applied.

Until you get your WBO2 back, we're not going to be much help. In the meantime, do a RAFIG and get the idle sorted out. Look at B4309 (also has weird values) as well.

[BagD72Chevy]

Sounds like a plan. I was looking at the VE table after I posted and I can see its rough. I've been doing AutoVE log tuning per the tutorial but its obvious I didn't hit all the cells.

Thanks

[joecar]

Note:

your B3618 is set to 1.00 and your B3605 is set lean at load... this poses a danger to your engine if you run it at any significant load...

set your tunetool fueling units to EQR and edit your B3605 to be suitably rich in the high MAP columns...

and set your B3618 to the same value as the high MAP columns of B3605.

Also set B3609 to 0.01 s.

[joecar]

C6001: setting the MAF DTC's to Not-Reported will not fail the MAF (as you have in C2901)...

for the MAF to be failed (and SD mode to be active), a MAF DTC must be present...

otherwise if no MAF DTC is present, then the PCM continues to use the MAF...

this is probably why your VE table is messed up (trying to correct VE while MAF is the source of air).

[BagD72Chevy]

Thank you very much Joe!

I actually haven't started the truck since I made this post. I have been reading 3-4 hours a night here on the forums just trying to absorb as much as I can. I think it was your comment in another thread that tipped me off about the MAF problem and to set it to non-emissions.

Thank you for the input, I will address these issues. My girlfriend works for Moates and got me a Roadrunner ECU for Christmas so I've been dabbling with that some too. The RTACS process looks pretty intriguing.

[joecar]

The RR is a very cool tool, nice of your girlfriend to get you one.

[BagD72Chevy]

Not to leave this thread hanging incase it helps someone else out. Changing the MAF DTC's to non-emissions fixed the idle issue. I also started over AutoVE tuning the truck and have a nice looking, much smoother VE Table from about 3400rpm down. I am going to work on the higher rpm this weekend, but a 2 into 1 exhaust, mid length headers, no-cats, and a 3.5" dynomax bullet isnt exactly stealthy running around town. With all I have read and learned I finally have a better understanding and plan of how to hit all the cells. For other newcomers I used the brakes to modulate rpm and throttle to modulate MAP value maintaining smooth throttle movements. I was careful not to overheat the brakes but this allowed me to hit cells I was having trouble getting with just standard driving techniques. I'm going to head out to an almost abandoned highway outside of town to get the rest of the map. My first impression is wow. When I first converted it to efi it was awesome. But it runs so smooth now with better tuning and drive-ability is amazing. Here's a pic of my setup.

http://i27.photobucket.com/albums/c200/rgoiti1/null.jpg

[EagleMark]

My girlfriend works for Moates.....Plan a day when Craig and Dave are there and buy lunch!

You said you had 3400 RPM down working well. Look at your VE table and build it up from 4000 RPM up before you start tuning there. Also set PE AFR to 1.0 for tuning, then when done set to 1.15 or? To get EQ ratio to add fuel for lower AFR/Lambda. It drops like a rock at 4000 RPM where the system runs strictly off MAF.

[joecar]

If you do set PE to 1.00 then make sure you can provide sufficiently rich fueling at load/WOT (don't let your WOT fueling be stoich).

[joecar]

Did you take care of this:


Note:

your B3618 is set to 1.00 and your B3605 is set lean at load... this poses a danger to your engine if you run it at any significant load...

set your tunetool fueling units to EQR and edit your B3605 to be suitably rich in the high MAP columns...

and set your B3618 to the same value as the high MAP columns of B3605.

Also set B3609 to 0.01 s.

Your B3505 is dangerously lean in the lower right quadrant (engine damage imminent if you operate at WOT or significantly high load)...

do this immediately:
- in tunetool, go Edit->Properties, set fueling units to EQR, restart tunetool;
- set your B3605 to stock (high MAP columns should be at EQR 1.165 at operating temperature);
- set B3618 to 1.165 EQR all across;
- set B3616 to 65% below 3000 rpm, and to 35% above 3000 rpm.