TexasCheddar

My car:
1994 Honda Civic EX 1.6 Automatic Transmission 134,000 miles

The Problem:

It waits too long to shift up when accelerating...
Ex: If I take my foot off the accelerator (around 35 mph), the car suddenly pops into a higher (more optimal) gear... guessing 3rd gear

It also shifts down too quickly when decelerating...
ex: When slowing to a stop in residential neighborhoods (around 20 mph), the car suddenly pops into a lower (less optimal) gear... guessing 1st gear

Also:
While coasting (decelerating from 20mph to 15mph), the car occasionally jumps from one gear to another, like it's confused about what gear it's supposed to be in.

The transmission is ALWAYS in gear. It never "slips". It's just like the car is confused about what gear it's supposed to be in.

When the car DOES shift, it's usually fairly jerky. But that would make sense if it's shifting up and down at the wrong RPMs, right?

I'm a newb, but it seems like this is a problem with some malfunctioning sensor, or a cable, or setting that is out of calibration.

Please help.

One last note: There is a gear (I believe 3rd) that shakes the car whenever it's approaching 4th gear. I've tried changing my shift selection from D4 to D3, and when I do that, the shaking goes away. I don't know if this is related, but it's not a tire/alignment issue, I know that.

EJ8mike

R u running honda atf?

carlos8

The problem from 3rd to 4rt can be a solenoid.

But the problem with you need to lift your feet from the gas to easy the trans. to shift is more commonly a pressure issue or wear.

The jerking in most cases is caused by the wear of certain hard parts, i.e. Wear in the clutch drum or the separators between hard parts (like flat washers in metal, bronze or plastic). A not correctly working oil pump can cause this issues and all this lose material goes directly to your pan and then to your filter and converter.

Make a simply check in your dipstick, if the oil in it smell to much like burn, clutch or locking with shine debris. You always can take off the oil pan and see.

Diagnosis a AT by words is not easy.

ewilliams1990

Any CELs?

TexasCheddar

wow... i think i fixed it...

A friend of mine said it might be my tps. I tried unplugging it, and starting the car to see how it would run... (I know that's not that best idea)

But... the shifting... all I can say is wow...

It's never shifted like this before... smoooooth...

To answer your question, no, no CELs were present. Of course when I unplugged the TPS then there was a CEL...

Now I have two questions:
1. Does this mean without a doubt that the TPS is faulty?... unplugging it just made it where the computer couldn't control a bunch of things...
2. If you had to decide, would you leave the TPS unplugged or plugged in until it was replaced... knowing that with it plugged in, it shifts badly...

carlos8

in our shop we have this problem a lot with Mitsubishi's specially in Nativas
(Montero sport). And yes the TPS malfunction give a bad read to the tranny ECU and begin to shift and downshift improperly.

TexasCheddar

I'm really new to fixing cars but is unplugging stuff always a good option???

I mean, I would have thought the car could really mess up from doing that but so far it's helped diagnose a variety of electrical issues...

crazyhouse2011

Go to autozone and pick one up. Simple swap.

TexasCheddar

autozone price: $45
ebay price: $6

... If it were an axle or a strut or a piston I were buying I'd worry more about buying from ebay... but this... this is a sensor... what are the odds (even a lesser build quality) sensor will go out again?

** why do I feel like you're flipping me off **

JDM-Punk

ive sold parts for over 7 years now (both oem and oe style/aftermarket) and you would def be surprised at how shitty electronic parts can be made/sold... with that said, there is prob not much of a difference in autozone and ebays product.. at the least, i'd recomend doing some research in the brand you are buying (as some have a very high failure rate)

TexasCheddar

I prolly should have just kept using this thread, I made another one though, mainly because the goal of my troubleshooting has changed. I'm not trying to solve downshifting, now I'm trying to fix stalling and stutters...

https://honda-tech.com/forums/showth...7#post49218897