Can't get it to idle
09-13-2011, 05:25 AM
#1
Can't get it to idle
I switched to speed density a couple weeks ago, but have been driving on the old MAF tune because SD refuses to idle without surging or hanging. I was following a procedure on LS2 idle tuning on the HP Tuners forum, only to discover that the final idle airflow minimum table I was modifying was doing nothing. I maxed the values for minimum airflow at 8.5lb/min which should put idle at the rev limiter, and it was completely unresponsive. In the log I command 1000rpm idle around frame 475, and it struggles to make it there. Still can't upload .hpt files..
Ideas or experience with this? Wasted like 6 hours figuring I was a dumbass and wasn't doing it right...I wasn't happy when I discovered the table wasn't even working
Ideas or experience with this? Wasted like 6 hours figuring I was a dumbass and wasn't doing it right...I wasn't happy when I discovered the table wasn't even working
09-13-2011, 08:31 AM
#2
I had a similar problem. Are you running rich at idle, and lower kpa? I was and it was due to my injectors being fairly large. I assume you have larger injectors as you are making a lot more power than me. I ended up having to lower my minimum pulse width way down to correct this. Also make sure your voltage correction is nailed down. I am not sure how to do this in HPT as I use EFILive. Hope this helps.
09-13-2011, 08:43 AM
#3
The injector data came from Greg Banish, so that should all be fine. They are SD60s. It actually runs a bit lean (5-6%) for a few seconds at startup and then fuel comes back in line. Haven't investigated that startup deviation because it doesn't seem to cause a problem. I've got idle fueling within 1%. After I get tired of messing with it, I flash my MAF tune back in and it idles like a stock truck.
09-13-2011, 09:15 AM
#5
Hah I actually got the cylinder balance test to work and everything looked perfect 
Here's the table I was working on with the procedure from HPT forum
And the one from the MAF tune that works great until I put it in the SD tune...
I tried jacking up the values for neutral and park for 1000rpm and higher to max value and there was zero change. I have a feeling theres some tiny setting somewhere that I've missed and its ignoring the minimum airflow tables because of it...
Here's the table I was working on with the procedure from HPT forum
Code:
Gear 200 400 600 800 1000 1200 1600 2000 2500 3000 3500 4000 4500 5000 6000 7000 8000 1st 0.0000 0.9001 1.0500 1.4049 1.7201 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 2nd 0.0000 0.9001 1.0500 1.4049 1.7201 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 3rd 0.0000 0.9001 1.0500 1.4049 1.7201 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 4th 0.0000 0.9001 1.0500 1.4049 1.7201 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 5th 0.0000 0.9001 1.0500 1.4049 1.7201 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 6th 0.0000 0.9001 1.0500 1.4049 1.7201 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Neutral 1.0001 1.0001 1.0936 1.1900 1.4636 1.8217 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Reverse 0.0000 0.9001 1.0500 1.4049 1.7201 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Park 1.0001 1.0001 1.0936 1.1900 1.4636 1.8217 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
Code:
Gear 200 400 600 800 1000 1200 1600 2000 2500 3000 3500 4000 4500 5000 6000 7000 8000 1st 1.0450 1.0450 1.0450 1.0781 1.2435 1.3889 1.7064 1.9446 2.2224 2.4340 2.6985 2.8308 2.8969 2.9233 2.9233 2.9233 2.9233 2nd 1.0450 1.0450 1.0450 1.0755 1.2156 1.3388 1.6263 1.9048 2.1694 2.3120 2.5794 2.7249 2.7910 2.8176 2.8176 2.8176 2.8176 3rd 0.9823 0.9823 0.9823 1.0120 1.1112 1.2799 1.5917 1.8080 2.0826 2.2908 2.4828 2.6161 2.6709 2.6709 2.6709 2.6709 2.6709 4th 0.9128 0.9128 0.9128 0.9128 0.9789 1.1443 1.4868 1.7938 2.0583 2.1534 2.1958 2.1958 2.1958 2.1958 2.1958 2.1958 2.1958 5th 0.9789 0.9789 0.9789 1.1112 1.2435 1.4551 1.8124 2.1958 2.5264 2.6455 2.6985 2.6985 2.6985 2.6985 2.6985 2.6985 2.6985 6th 0.9789 0.9789 0.9789 1.1112 1.2435 1.4551 1.8124 2.1958 2.5264 2.6455 2.6985 2.6985 2.6985 2.6985 2.6985 2.6985 2.6985 Neutral 0.8466 0.8466 0.8466 0.9409 1.0450 1.1773 1.4419 1.6798 1.9842 2.1958 2.1958 2.1958 2.1958 2.1958 2.1958 2.1958 2.1958 Reverse 0.8466 0.8466 0.9526 1.1112 1.1905 1.3096 1.6535 2.0239 2.2885 2.5662 2.5662 2.5662 2.5662 2.5662 2.5662 2.5662 2.5662 Park 0.8466 0.8466 0.8466 0.8905 0.9637 1.0830 1.1471 1.3396 1.6328 1.7429 1.7886 1.8620 1.9444 1.9994 2.0637 2.1461 2.1958
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09-14-2011, 08:57 AM
#8
Well I've isolated it to the throttle body. Raising idle in the bi-directional controls doesn't open the throttle any more, it just increases RPM error which pushes the adaptive idle advance up.
I raise up the idle with the controls in both log files; only the MAF log opens the throttle more. Somehow with the SD tune, the throttle body isn't getting the memo.
I raise up the idle with the controls in both log files; only the MAF log opens the throttle more. Somehow with the SD tune, the throttle body isn't getting the memo.
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