88 Dead Battery-Now Transmission Problems - Help.
Thread Starter
Instructor
Joined: Nov 2008
Posts: 169
Likes: 17
From: Harrisonburg VA
88 Dead Battery-Now Transmission Problems - Help.
I have a stock 88 with 90K miles. One evening this week I left an interior light on overnight and ran the battery completely down. I jump started the car with a battery pack and now the transmission (automatic) is not working correctly. When I first start the car and put it in drive it really bumps into gear. Then I have to run the RPMs up to about 3k+ to get it to shift into each gear, bumping hard each time. The engine does not hold back when you let off the gas. The car is in a free coast and the engine RPMs drop to idle speed as soon as I let off the gas. The longer I drive it, the better the shifting gets. If I can get up to about 70 mph it will shift to OD then everything seems to return to normal. As soon as I turn the ignition off it starts all over again.
Fluid level, color and smell are all normal. It seems to be electronic. I have been driving it like this three days and no change. Did I damage the ECM jump starting it? Where do I start?
Thanks for you help.
Fluid level, color and smell are all normal. It seems to be electronic. I have been driving it like this three days and no change. Did I damage the ECM jump starting it? Where do I start?
Thanks for you help.
Instructor
Joined: Aug 2009
Posts: 146
Likes: 0
From: Broadway Virginia
Are you getting any codes?
FWIW, I fried my ECM one time using a boost setting on a battery charger. I won't do THAT again. It turned on my trouble light, and gave me a code that I cannot remember.
FWIW, I fried my ECM one time using a boost setting on a battery charger. I won't do THAT again. It turned on my trouble light, and gave me a code that I cannot remember.
Instructor
Joined: Aug 2009
Posts: 146
Likes: 0
From: Broadway Virginia
I do not know if this will help, but it is worth a try. How about disconnecting the battery for several minutes, then reconnecting and see how it does?
I did have a faulty vacuum modulator on a Jetaway 2 speed trans (1967 Olds Cutlass) that gave very similar symptoms until I replaced it. But that would have no connection whatsoever with a dead battery.
I did have a faulty vacuum modulator on a Jetaway 2 speed trans (1967 Olds Cutlass) that gave very similar symptoms until I replaced it. But that would have no connection whatsoever with a dead battery.
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
In a 1988 there is nothing in the transmission that is controlled by the computer other then torque convertor lock-up. Your problem is something else like TV cable adjustment or ??? The jump start is not the issue.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
On the TV cable, (it is the one with the white button on the side) there will be a blackplastic tube (sheath) around the cable coming out of the thing with the white button(adjuster).
Look at that tube, and if there is a wear mark, push the white button and push the black sheath back till the wear mark lines up withthe edge of the adjuster.
Rock the sheath till the white button locks in the full outboard position, so it can grip the sheath. Give it a drive, and see if it changes.
Mine, for some unknown reason, vibrated loose, and the cable slipped, and the trans was wierd till I put the sheath back to the wear mark.
Look at that tube, and if there is a wear mark, push the white button and push the black sheath back till the wear mark lines up withthe edge of the adjuster.
Rock the sheath till the white button locks in the full outboard position, so it can grip the sheath. Give it a drive, and see if it changes.
Mine, for some unknown reason, vibrated loose, and the cable slipped, and the trans was wierd till I put the sheath back to the wear mark.
Last edited by coupeguy2001; Aug 9, 2010 at 10:15 AM.
Thread Starter
Instructor
Joined: Nov 2008
Posts: 169
Likes: 17
From: Harrisonburg VA
found it!
It was the TV cable. Went home and looked it up in the FSM manual. Opened the hood and there it was, the end of the cable was broken off. It has a little plastic clip that was broken. It had nothing to do with the dead battery. Isn't it funny how you can jump to conclusions? 
Anyway, thanks for you help!
Anyway, thanks for you help!
Last edited by avgjoe; Aug 9, 2010 at 09:50 PM.
