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I'm trying to figure out why my truck shifts great at WOT from a dead stop on the 1>2 (6,300-6,500, still dialing it in for 6,600) but when cruising at say 15mph, 2nd gear and I hit it, it down shifts to first then revs to the 7k rev limiter. Am I missing something that would cause this?
Log: http://73-ls1.com/63truck/Mike_ride.hpl
Tune: http://73-ls1.com/63truck/8_22_07.hpt
It looks to me like your upshift conditions are met well before the
commanded gear changes. Nice 4-2-1 downshift. :) It seems like
there is plenty of time between downshift and meeting the upshift
thresholds (almost 3 seconds).
I wonder if there is some abuse-mode timeout or something that
holds off the commanded shift. But it looks like abuse mode is
disabled. It does look like a "mental problem" though, judging
by the Current Gear transition vs the MPH, RPM.
Anyone else have ideas.. Confirmed it again today with a 7k rpm 2>1 downshift :( I really would like to stay off the limiter...
change your wot to match your shift tables 100% tps, its set at 45mph, you need to change it to 36mph as well copy your normal shift table to your hot table aswell
Your .hpt file is from a 2002 Camaro 4L80E trans. What year & model truck are you working on? What size rear tires?
Russ Kemp
Russ. The truck is a hybrid, 63 C10 pick up running a 1999-2002 F-body PCM and harness but using a 4L80E trans. It's got a 275/50/15 radial tire which is is similar in size to the factory F-body 275/40/17. I'm also running a 3.73 rear gear. All of this has been updated in the file though.
The 1>2 shift is perfect if I am at a dead stop launching the truck, but any time it goes from anything 2nd or higher to 1st, it comes to the limiter and I have to lift and hit it for it to shift.
Klymaxr, I'll try your advise.
Super73,
Try this tune, a 26.1 advertised tire dia is actually 25.3 calculated tire dia to be used in the tune file. I set up the shift pressures & shift speeds to match the gear ratios of the 4L80E trans.
As for the stalling when coming to a stop, I made some changes to you tune to help. Use my idle .cfg file, and do a cold start scan in park till operating temp. Don't touch the throttle or move the car until after you stop & save this scan log.
Russ Kemp
Russ,
Check the Gen 3 section as I have a cold fire there using your .cfg already.
But my most recent log, clearly shows tq management coming in as I come to a stop and that's when it dies. Where TQM was not induced, it idled fine coming to a stop.
I'm thinking I should open a new thread and consolidate my issues and title it "todays issues"
Russ I'm having this same issue on an 07 silverado classic, could you please take a look at it? It shifts fine at WOT through all the gears until you downshift, then it won't make the 2-3 shift unless you lift out of the throttle. I just can't see why this is happening.Quote:
Originally Posted by Russ K
im battling same issue with a 99 TRUCK PCM in a lexus is300 swap with a built 4l60e though... same exact problem driving me nuts.. had to raise to 7k limit it bumps as it shifts.. watching the status bits its not commanding it to shift way past the conditions.. ive tried several different tire/gear combos mph shifts and rpm it makes absolutely no difference.. seems 39mph shift no matter what I do or tell it to do..ive noticed mine shift correct few times but nom im wondering if I was slow enough for it to already be in first on these attempts...
I have the same issure exactly any 1 figure out more ideas