1 have a 98 k1500 suburban with 198000 on it seems to run great. The tcc cluch would kick in and out at 60 or below in only in od since Iv had it.. all the sudden the other day it started doing it in 3rd at any speed between 40 and 65. Trans was serviced and full time up about 15000 miles ago.???? Tested tps good. Cleaned maf and spray cleaned intake w seafoam at 2000 rpm. Did the trick for about 25 miles tcc lock up worked great in 3rd and od. But then right back to the same... please help.

 

[QUOTE=Big river;88454]1 have a 98 k1500 suburban with 198000 on it seems to run great. The tcc cluch would kick in and out at 60 or below in only in od since Iv had it.. all the sudden the other day it started doing it in 3rd at any speed between 40 and 65. Trans was serviced and full time up about 15000 miles ago.???? Tested tps good. Cleaned maf and spray cleaned intake w seafoam at 2000 rpm. Did the trick for about 25 miles tcc lock up worked great in 3rd and od. But then right back to the same... please help.
so... I have checked / replaced all applicable sensors. Still having problem.
I did another intake clean with Seafoam intake cleaner. At 2000 to 3000 rpm. So far so good running great shifting great tcc working great. What ever is causing the problem is definitely inside the intake. I will keep posting updates if problem comes back