1991 overdrive question

[sp_longhorn]

I am sure this has been posted before. 1991 overdrive constantly kicking in and out of overdrive around 45 to 55 mph. Worse in winter months than summer. Tps? is it what's causing the problem

 

["Mad Max"]

SP -



I was having similar problems with my 93... and after much discussion and a final fix tip from our own NASCAR Mark, I 'tightened the nut'. Under the TPS switch - wait, okay - I have an automatic, so the brackets I mention regarding this fix are pertaining to an automatic pump.



Also, I hope I have the parts labled correctly, but this should do the trick. On my rig it would kick out of od all the time, and only when you lift off the throttle would it go back in... then pour on the coals and it'd kick back out - frustrating as hell So, I'm 99% sure about this fix, and it was really really simple - almost too simple but I'll take it anyways. The square plastic TPS switch is bolted via two thin/long bolts to a bracket that is bolted to the diaphram housing. Under the TPS switch, under the bracket, is of course the axis for the pump lever, and directly under the bracket is a 13mm (?) nut that is threaded on the axis. The nut is just above a 6 (?) -sided plastic male socket that seats into the pump lever, just below the nut. All I did was tighten the nut, clockwise on the axis lever - that's it. I only had to tighten the nut about 1/2 turn until it got snug (it was loose)... . and after over two years of driving it the OD has NEVER, EVER kicked off, ever. When I want it on, it's on, period.



Now, some of the guys in here may have to elaborate on this fix, but man did it work for me. I'm not even sure if I didn't accidentally tighten something else, but just snug up that nut (don't crush it!) under the TPS switch and see if that works out. If so please repost so I'll know if I'm blowing smoke up my own... well anyways, there it is.



Oh, while you're at it, change out the shifter lever on the column to the 2nd gen version - have a look at my readers rigs for a pic of the newer switch - OD operation will never be the same. You'll actually start 'shifting' with the OD - I love it.



- Sam

 

[LEggers]

Same as above...