Jemo

I have a stock 5.3L with 4L60e and Vigilante 3200 stall in my '56 Chevy. Around town the car shifts fine but it seems when the speedo hits 40 mph, whether you get there in a hurry or slowly, the car shifts into overdrive and from there on up will not downshift and will stay in overdrive. As you come to a stop again, it will shift back into 1st gear so it seems alright in that regard.

This is in a newly rebuilt transmission and I have about 200 miles on the car so far. Otherwise, it starts, runs, and drives fine.

Any ideas what to check?

jsteele90

iTrader: (13)

my car just recently started doing this as well before i left.. a few people told me to check into the maf. being that ive been away from my car for a month and am currently in afghan i cant troubleshoot the problem any further. lol

ls1blazer

iTrader: (6)

Mine did it today. It won't downshift until it completely stops. It also changes gears faster. This morning it would'nt shift at all through the first few stop signs. At one point it acted like it was low of fluid. rev'ed to 3500 and jerk into gear. After it warmed up it changed gears fine other than the downshifting.

ls1blazer

iTrader: (6)

Found the problem...tps sensor.

JoshuaGrooms83

iTrader: (2)

huh, was the TPS dirty or faulty? im wondering about his too sinc eim suddenly having the same issue of the engines reving but cars not pulling at WOT and wont downshift when I floor it on the highway. it was before a couple weeks ago but now its doing this crap.

Carter01

iTrader: (11)

Is this a new build?

If not a new build did it just start acting this way?

Has the tune been adjusted for the stall?

RevGTO

iTrader: (12)

Sounds like a tuning issue to me. In that case, it would be that the converter is locking up too early, and the tune is requiring a high TPS % to allow it to unlock and downshift.