# 64 Tbird Carb Or Trans? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** acceleration\ **Created:** [December 29, 2007, 7:38pm UTC](https://community.cartalk.com/t/64-tbird-carb-or-trans/8808 "2007-12-29T19:38:24Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Robert\_Tbird\_64](https://avatars.discourse-cdn.com/v4/letter/r/5e9695/32.png) [@Robert\_Tbird\_64](https://community.cartalk.com/u/Robert_Tbird_64)\ **Post date:** [December 29, 2007, 7:38pm UTC](https://community.cartalk.com/t/64-tbird-carb-or-trans/8808/1 "2007-12-29T19:38:24Z")
When I am driving my 64 Tbird at highway speed and accelerate to pass, my engine races, I lose power and leave a cloud of black smoke. Backing off the pedal, it returns to normal. It has the 390, 4bbl and Cruisomatic. The eengine and carb were re-built and have about 10k miles. The trans shifts well. What do you think? ---
**Author:** ![GreasyJack](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@GreasyJack](https://community.cartalk.com/u/GreasyJack)\ **Post date:** [December 29, 2007, 8:26pm UTC](https://community.cartalk.com/t/64-tbird-carb-or-trans/8808/2 "2007-12-29T20:26:49Z")
If it’s revving up, but losing power it’s a transmission issue. The puff of black smoke is probably due to a rich condition due to the engine going from heavy load to no load instantly due to the transmission issue. I don’t know that much about Ford Automatics of this vintage, but I’m sure some of the other people here can give some suggestions. ---
**Author:** ![Robert\_Tbird\_64](https://avatars.discourse-cdn.com/v4/letter/r/5e9695/32.png) [@Robert\_Tbird\_64](https://community.cartalk.com/u/Robert_Tbird_64)\ **Post date:** [December 29, 2007, 11:59pm UTC](https://community.cartalk.com/t/64-tbird-carb-or-trans/8808/3 "2007-12-29T23:59:43Z")
Thank you for your reply. Not the answere I was hoping for! ---
**Author:** ![BustedKnuckles](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bustedknuckles/32/25_2.png) [@BustedKnuckles](https://community.cartalk.com/u/BustedKnuckles)\ **Post date:** [December 30, 2007, 3:30am UTC](https://community.cartalk.com/t/64-tbird-carb-or-trans/8808/4 "2007-12-30T03:30:46Z")
It may not be the transmission internally, but the vacuum modulator. Automatics used a vacuum modulator to regulate the shift points until the introduction of the TV cable in the '80s. If the modulator has a leak, it could let transmission fluid into the intake manifold to be burned in the engine, causing smoke. A quick check is to find the vacuum line that runs down to the tranny, disconnect it at the intake manifold, and check for any trans. fluid. It should be dry if everything is good. ---
**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\ **Post date:** [December 30, 2007, 2:47pm UTC](https://community.cartalk.com/t/64-tbird-carb-or-trans/8808/5 "2007-12-30T14:47:44Z")
From the old Chilton manual, Runaway on forced downwhift; maladjsuted front band or inoperative front servo. Leaks in hydraulic system or sticking valves in valve body. ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [December 30, 2007, 3:06pm UTC](https://community.cartalk.com/t/64-tbird-carb-or-trans/8808/6 "2007-12-30T15:06:13Z")
The engine races because the transmission downshifts, thats what its supposed to do. The loss of power and the black smoke indicates a carburetor problem, but it could be the previously mentioned vacuum modulator or simply an ignition problem. 10k miles is about the limit for sparkplugs and points in this car. ---
**Author:** ![charles](https://avatars.discourse-cdn.com/v4/letter/c/6f9a4e/32.png) [@charles](https://community.cartalk.com/u/charles)\ **Post date:** [December 30, 2007, 6:09pm UTC](https://community.cartalk.com/t/64-tbird-carb-or-trans/8808/7 "2007-12-30T18:09:22Z")
ok guy I just had same problem with 1958 old conv. red in color white and red inside white roof. what a looker. $45000.00 will make any car look great. I found out out it was not the color red. I did know how to rebuild the carb but I gave it some a carb shop to rebuild and it was worse. after three times doing the repairs. we found a a guy in washington from olds club who does carbs and we got a great one from him. It is the carb. look on web site for a place that sells rebuild carbs. if your not sure on how to adjust a carb. get with a local rod hot club. . make sure they use a vacuum hose and gage to do this . not just turn air mixture in and out .