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General Site Info => General Discussion => Topic started by: dumbucket1 on September 16, 2008, 02:01:55 pm

Title: no overdrive in my moms car need ideas
Post by: dumbucket1 on September 16, 2008, 02:01:55 pm

its a 94 buick regal. It has the buick 3800 series motor. Im not sure what transmission. Its not shifting into overdrive for some reason. I have verified this by taking it up to 65 mph and manually shifting it from overdrive to drive with no change in rpms. But when you let off the gas at 65 it goes from 3k rpm's to 1k rpm's. The tranmsission shifts in all other gears just fine. any ideas?

Title: Re: no overdrive in my moms car need ideas
Post by: dumbucket1 on September 16, 2008, 02:58:28 pm

somebody told me to try lifing up on the brake pedal with my foot on highway speeds and see if that would make it shift. i tryed that and it did shift into overdrive, or what seemed like overdrive. the rpm's dropped from 3k to 2k

Title: Re: no overdrive in my moms car need ideas
Post by: ccz145a on September 16, 2008, 03:11:52 pm

looks like you found the problem. So would that be a return spring (I don't think one is there) or a brake switch adjustment?

Title: Re: no overdrive in my moms car need ideas
Post by: dumbucket1 on September 16, 2008, 03:44:17 pm

I think it needs the brake switch adjusted but I think that only controls the tcc

Title: Re: no overdrive in my moms car need ideas
Post by: Lt.Del on September 16, 2008, 04:23:48 pm

I am surprised the battery doesn't die, for if it is the brake switch (or low brake fluid) causing the brake switch to activate when not supposed to, it would also keep the brake lights on, ignition on or not.

Title: Re: no overdrive in my moms car need ideas
Post by: dumbucket1 on September 16, 2008, 04:29:53 pm

actually no the brake lights did not stay on  ???

Title: Re: no overdrive in my moms car need ideas
Post by: ccz145a on September 16, 2008, 04:48:23 pm

there is probably more than one switch down there using the same bracket. just a thought.

Title: Re: no overdrive in my moms car need ideas
Post by: Dragon on September 16, 2008, 11:14:22 pm

The Regal should have a 4T60E, basically a FWD 4L60E with a trans axle.....  There should be two switches located on the brake pedal, that look the same, but one controls the Brake Lamps, and the other(Top One??) disengages the Torque Converter Clutch (TCC) solenoid..

Title: Re: no overdrive in my moms car need ideas
Post by: VileZambonie on September 17, 2008, 10:31:45 am

Yes the TCC brake switch is used for unlocking the converter not for overdrive. also check the vacuum modulator hose and make sure it's connected.

Title: Re: no overdrive in my moms car need ideas
Post by: dumbucket1 on September 17, 2008, 04:38:32 pm

the vacuum line is hooked up to the module but up where the vacuum line comes out of the throttle body the rubber has a few cracks. It doesnt seem to be sucking any air there but I will replace the rubber anyways and see if it makes any difference.

Title: new problem, fuel
Post by: dumbucket1 on September 25, 2008, 03:00:23 pm

got the overdrive fixed just for a new problem to come up  ;D. Ok if the car sits for about an hour it cranks for about 20 seconds and when it starts there is a heavy gasoline smell. If you get out of the car and back in within an hour there is no smell and the car starts with a tap of the key.

Does this sound like leaking fuel injectors? I cant find the test port to check the fuel pressure. Its the buick 3800 engine. Thanks for your ideas.

Title: Re: no overdrive in my moms car need ideas
Post by: VileZambonie on September 25, 2008, 03:21:33 pm

It's right on the fuel rail. What was wrong with the trans?

Title: Re: no overdrive in my moms car need ideas
Post by: dumbucket1 on September 25, 2008, 03:45:06 pm

rotted rubber vaccum line was the cause of the tranny problem. I have been up and down the fuel rail and there isnt a port for checking fuel pressure.

Title: Re: no overdrive in my moms car need ideas
Post by: dumbucket1 on September 27, 2008, 09:04:47 pm

never did figure out the hard start and gas smell but I ran some sea foam thru a vaccuum port and then put the rest in the gas tank and now it starts with just a touch of the key and no more gas smell  ;)