Braking?, Downshifting?, RPMS? Please Help!

[DenverLXI]

I'm in dire need of some help.

When I'm driving normally (about 35-50mph) and I push the brake (like if I'm coming to a stoplight), my car downshifts, causing the car to jerk like if I had a manual transmission. But since mine is an automatic, it shouldn't be doing this. Also, sometimes when I'm driving the RPMs will Rev up to around 5,000 without me doing anything, and then go back down causing the car to hesistate. I'm getting worried, and I hope it isn't the tranny. The car has been working fine up to about a week ago. I just replaced the tranny a little over a month ago and it has 122,000 miles on it. The car has 177,000 miles on it. I'm in desperate need of an oil change, so that's being done today. I checked the tranny fluid and that's okay. Does the oil have anything to do with it? Is it fuel related? Any and all help is appreciated.

[DenverLXI]

Also my car doesn't start up as good as it used to. It sometimes revs to 1500, then dies a few times before getting enough juice to keep the RPMs up.

[smufguy]

how do u know the tranny fluid is okay? Does it look pink or did u change it? Was the filter screen in the tranny changed?

Next, Get yourself some new oil and Motoflush and Engine restore and some Carb cleaner. You can get all these from Walmart as you know. For the carb cleaner, get the 75cent one, it works just like the 5 dollar one.

come home, set up ur car for an oil change. pour in the motoflush where u pour ur oil and let it run for a while. then drain the oil out and filter. change the oil and then pour in the engine restore.

While this is going on. expose your Throttle body and spray some carb cleaner on the butterfly valve and wipe it clean. I would suggest u take it out fully and clean it on the reverse side too. It makes whole lot of difference. Dont forget to spray some and remove the build up on ur throttle linkage on the TB too.

Put everything back and fire up the car and warm it up and take it for a drive. check if it does it again, if it does that again. Then see where u normally idle at.

Next thing, see how ur coolant is. Has it been changed anytime soon? Was it added with water in the right propotion or does it have more than 70% coolant? Cause 70% is the max percentage of collant you can go for normal operation and its for colder climate like northern america.

Again take it for a drive and see what it does, does it do that again? Grab urself a fast idle valve from the junkyard and try to replace it and see what it does. Sometimes they fix it if it does not then its ur ignition could be at fault.

Change the plugs and torque them to 13ft.lbs. This is crucial cause u dont wanna screw up ur head. cap and rotor and wires should fix it most likely.

Nothing works or the problem is still there. Get yourself the $7 gauranteed to pass emission bottle, its a high cleaner with a lot of detergents and methanol i guess to clean up ur entire fuel system. Do this pour in thing, after u have changed your fuel filter.

oh yeah, dont forget to check for any vaccuum leaks from your TB.

[DenverLXI]

The tranny fluid was changed when I had the new tranny installed. I checked the level and the color seems to be okay. I know the filter screen wasn't changed. I though that we couldn't change the filter screens on our cars because its way up in there that it's too difficult to reach. Am I wrong? I'm going to get some Motoflush & Engine Restore and see what happens. They both are to be poured where the oil is poured right? I'll get some carb cleaner too.

[BITESIZE]

My car used to do that with the auto... I think your tranny is going to take a big shit on the road one these days.

[shepherd79]

sounds like your tranny is on the way to junk yard.
you have two choices, replace the tranny with another good condition used one or rebuild one (man it would cost you).
i would go with replacing it with another used one, or swap the 5 speed.