Help with touchy pedal / rpm flaring during take off
Swap is from a 2003 suburban. 5.3/4l60e/e59 pcm blue/green. Bought the whole rig as a driver and used all swap parts from that vehicle.
going into an old chevy truck.
Engine is all stock with only air intake and shorty headers.
changed the 2 shift solenoids while doing trans pan and filter.
I would like to say that the truck drives great except for one area. Street take offs.
WOT from a stand still and at speed works great. shifts in every gear as it should.
part throttle transitions above 30 are also good.
However, taking off from a standstill (traffic light) can be a chore. the pedal feels like its all or nothing. i have to be very light footed taking off. When accelerating from a stop the transmission will flare a few times before it settles down. if i go over a bump while taking off the delay from the dbw will cause a really bad jack rabbit effect and since the truck is loud it can be embarrassing.
i also feel sometimes at slow cruising the shift from second to third lags and the revs will flare up before the shift. its almost as if the mph/rpm is having a mismatch in the pcm.
The tune is completely stock except for dtc modifications.
i also used the gear/tire wizard for the different sized tires and gears.
I added 5% to the shift pressure table and set shift time to .300 seconds.
drove it today and the shifting is definitely more crisp between 1>2 and 2>3.
But i still have the other issue.
Ive included both the tune and the log of todays test drive. Please let me know if there is something i can try to address these flareups and make the pedal more touchy.
The original suburban did have one of those adjustable pedals. i did cut and shorten the pedal and transferred it to the truck. it is a bit shorter but it has a nice long travel.
The truck is just a low cruiser. 95% of the time i just want to cruise the Blvd. or go to the beach. run errands etc.
its a bummer that it drives so good on the freeways but sucks to drive around town. once i can figure out how to tame down the part throttle response it will be perfect for me.
i took it out again. this time i did some quicker street starts to really mimic whats happening. they show up more towards the end of the scan.
i took 2mph out of the part throttle normal/performance/cruise tables. it seems to make it a little better. but i still feel like it hangs up around 35-38 mph and doesnt know whether to grab the next gear or not.
im really starting to believe this short pedal is causing the throttle to be more touchy. i guess ill try to temporarily mount it higher up on the firewall and extand the pedal to see if it will help at all. when it starts jackrabbiting ill see the tps% bounce between 25-65%.
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