LT1-LT4 Modifications 1993-97 Gen II Small Block V8

tune(shift problems)

Old 10-05-2008, 08:52 PM
  #1  
On The Tree
Thread Starter
 
clwz28's Avatar
 
Join Date: Jul 2008
Location: Sulphur Springs ,tx
Posts: 149
Likes: 0
Received 0 Likes on 0 Posts
Default tune(shift problems)

I was wondering if all lt1 autos hit the rev limit before they shift,mine does me shifting it,or leaving it in drive it cuts out and falls on its face about 5,800 then shifts ,and it seems alot worse since I installed my headers.I know its costing me a few tenths,will a tune fix this problem completely?
Old 10-05-2008, 10:18 PM
  #2  
12 Second Club
iTrader: (35)
 
Schweet97Z's Avatar
 
Join Date: Jan 2006
Location: Danville PA
Posts: 1,550
Likes: 0
Received 0 Likes on 0 Posts

Default

IMO a tune will be a band aid. If the transmission is hitting rev limiter then its most likely hurt. Same thing happened to me. I threw more horsepower at it and it blew the rear planetary up. Tore it apart and the 2-3 bands were gone along with the 3-4 on the way out. If you plan to throw some power at it, id suggest start looking into a rebuild.
Old 10-05-2008, 10:52 PM
  #3  
On The Tree
Thread Starter
 
clwz28's Avatar
 
Join Date: Jul 2008
Location: Sulphur Springs ,tx
Posts: 149
Likes: 0
Received 0 Likes on 0 Posts
Default tranny

trans is fine,only 5,000 mile on rebuild,but the shift points are off,it shifts firm.
Old 10-05-2008, 10:58 PM
  #4  
12 Second Club
iTrader: (35)
 
Schweet97Z's Avatar
 
Join Date: Jan 2006
Location: Danville PA
Posts: 1,550
Likes: 0
Received 0 Likes on 0 Posts

Default

how would the shift points be off due to a rebuild? did you have your pcm tuned before/after trans? you should have stock shift points still in the pcm if your still untuned.
Old 10-05-2008, 11:01 PM
  #5  
11 Second Club
iTrader: (17)
 
Armyman2445's Avatar
 
Join Date: May 2006
Location: Greenville SC
Posts: 574
Likes: 0
Received 0 Likes on 0 Posts

Default

I had the same problem with old trans. I had it rebuilt and it still did it. Turns out the speed sensor was bad. Changed it out never had problem since.
Old 10-05-2008, 11:22 PM
  #6  
Banned
iTrader: (12)
 
Elliott's94Z's Avatar
 
Join Date: Mar 2008
Location: Oregon Grown
Posts: 4,370
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by clwz28
trans is fine,only 5,000 mile on rebuild,but the shift points are off,it shifts firm.
When you say it shifts "firm" are you saying the tranny shifts hard into each gear? I had mine rebuilt and had a shift kit put in and it snaps you back into your seat when it goes into the next gear. I had Bryan at PCM4LESS do my tune. It still shifts into gears after. It doesn't shift at those rpm's you are saying unless I am putting the pedal to the floor.
Old 10-06-2008, 09:24 PM
  #7  
On The Tree
Thread Starter
 
clwz28's Avatar
 
Join Date: Jul 2008
Location: Sulphur Springs ,tx
Posts: 149
Likes: 0
Received 0 Likes on 0 Posts
Default ?

3/4 throttle,it will shift at 5600 in drive from 1st to second,shift it manualy at 5500 it shifts at 5600-5700 and does not hit the rev limit?
__________________
Old 10-06-2008, 09:56 PM
  #8  
TECH Regular
iTrader: (4)
 
Chevyguy358's Avatar
 
Join Date: Nov 2004
Location: Wilmington, NC
Posts: 427
Likes: 0
Received 0 Likes on 0 Posts

Default

yea mine does that and it was dyno tuned, it began after I replaced the 26' tall tires with 28's, prolly need to get that part tuned again


Thread Tools
Search this Thread
Quick Reply: tune(shift problems)



All times are GMT -5. The time now is 05:24 AM.