doesn't downshift correctly?

[RiceRocket18]

i was wondering, could vacume leak or the infamous DSM idle surge problem cause the car not downshift correctly when you slam on the throttle? because ever since i start having this damn idle problem the downshifting mechanism started acting weird. before the problem i was able to slam on the throttle (not WOT) while during cruizing speed and downshift easily to 2nd. and now it won't downshift to second while cruizing unless i do WOT all the way. or could this possibly be my torque converter or some other transmission issue.

i am having a shop put on my new Torque converter, shiftkit and end clutch i got from IPT this weekend. i wanna know what could possibly cause this problem so i know what to tell them. besides the already annoying idle surge shit problem i am already sick and tired of.

 

[RiceRocket18]

nevermind!.... now she downshifts fine again. !!... i give up!!.. what a moody bi***. sometimes decides to have problems of her own. i am sending it in to have the mech figure it all out.

 

[Budget90GST]

Were you able to figure this out. I was doing some search and found yours....I know it's old but was wondering if you have any update.

 

[the_mork]

I doubt that someone with 65 tech posts in a thread from 6 years ago will respond but I may be able to take a crack at it. If you are having identical symptoms then the very first thing to check is your throttle position sensor. If this sensor moves or goes bad it can cause both idle and shift problems as well as affect the way that your car accelerates.

If you have other problems or symptoms then please list them. Alternative but less common issues involved in failure to downshift are dirty or malfunctioning solenoids or stuck valves within the valve body.

FWIW if you plan on making much more than stock power there is not a better time than now to install a Translab shift kit in order to keep transmission work to a minimum, I've just installed one now and wish that I had done it when I first started modifying my car before I broke two transmissions. The work is detail oriented but quite simple. Attention to detail and accuracy are key but otherwise the job only requires a drill, a ratchet, a hammer, an 8mm and 10mm socket, an extension, and a screwdriver.

 

[Budget90GST]

Thanks for the response. I checked the TPS using my logger and it seems to work fine....I did do a transgo shift kit (similar to translab) and it inproved the shifting. My downshifting problems usually happens when slowing down from a cruise or steady drive down to low enough speed. If I come to a complete stop, the car shifts to first just fine. The only way I can force the shifting is by flooring the car which I dont like doing too much cause then I get into boost and usually have to slow down right away..I just want to accelerate normally. Any other suff I should check that can cuase the symptoms I mentioned? Again thank you.

 

[HighPSI TSi Guy]

Well the OP has a bad throttle closed switch.

Not sure what the second guy's problem is, but it sounds to me like you're driving a car with a automatic transmission.

 

[Budget90GST]

Just updating for people doing search. It was just TPS adjustment that cause my automatic not to downshift correctly. Thank you for your help.

 

[EclipZ]

when i floor my car it downshifts and then waits a few seconds and then downshifts again. what would cause that?

 

[definitiveno]

My car, when slowing for a stop at a stop light will downshift quite harshly into first. Only does this half the time. Works wonderfully with exception to a rough downshift when coming to a stop. Happens right around 4 mph.....

 

[the_mork]

This is somewhat symptomatic of bad end clutches which are exacerbated by a tendency for the stock transmission to try to do this anyway. Sign up on the Importperformancetrans.com forum for a $20(IIRC) coupon if you buy over $100 of stuff and get yourself a new set of end clutches and a translab shift kit. If you've roasted some end clutches you're likely being hard enough on your transmission that the extra protection of the Translab kit and it will make your car spend less time shifting and more time putting power to the ground.


FWIW if you do the Translab kit it should be noted that you don't need to take the solenoids off your valve body as shown in the VFAQ and at plymouthlaser.com, instead the plug for the solenoids has two ears on it that can be pressed in with a screwdriver and the whole plug will come out with the solenoids when you pull your valve body making the job much easier.

 

[definitiveno]

I already have the translab shift kit. I bought another new set of end clutches from IPT. The current new set has about 25 miles on it, but it is a factory set of end clutches.

 

[the_mork]

Also check that your throttle position sensor is working correctly.

 

[transdude]

This is somewhat symptomatic of bad end clutches which are exacerbated by a tendency for the stock transmission to try to do this anyway. Sign up on the Importperformancetrans.com forum for a $20(IIRC) coupon if you buy over $100 of stuff and get yourself a new set of end clutches and a translab shift kit. If you've roasted some end clutches you're likely being hard enough on your transmission that the extra protection of the Translab kit and it will make your car spend less time shifting and more time putting power to the ground.


FWIW if you do the Translab kit it should be noted that you don't need to take the solenoids off your valve body as shown in the VFAQ and at plymouthlaser.com, instead the plug for the solenoids has two ears on it that can be pressed in with a screwdriver and the whole plug will come out with the solenoids when you pull your valve body making the job much easier.

Is that why people pull the solenoids off the vb like that? I get valve bodies like that all the time and have always thought, "that's insane!"

Although, sometimes sometimes people just snip the wires

-John

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[the_mork]

That is why I did it the hard way the first time. It definitely is an issue that I wish was resolvable. Sometimes vfaq information is outdated/wrong but since it is a worthwhile site it is hard to tell people that there are problems and still get newbs to go there.

Perhaps when I get some time I'll add a tech thread to the site about the many small issues with automatic transmission installs, failures, and quirks just to have another resource to send people to for help. As far as I know there isn't an easy resource that covers common little things like making sure the torque converter is about 3/4 of an inch into the bell housing when installing or how to change the transmission pump when you fail to make sure that happens as well as updated instructions that don't suck on installing the translab kit. Even the vfaq for end clutch install isn't very good and suggests a silly way to compress the clutch while adding unnecessary complexity to the process.

FWIW also I'm glad to see you back being active on this forum, perhaps you never really left but I see you around in more threads now and your expertise is incredibly welcome here.

Finally, perhaps this is better for PM but I'll just put it here, do you by chance buy valve bodies and/or broken transmissions? I'm likely to put one good one together out of the three I have but there will still be two cores with varying amounts of damage just taking up space in my garage when I'm done. I could purchase some rebuild kits but it is more investment for less return than I would like when I'm strapped for funds going into a new semester.

@definitiveno, I'm no longer posting from my phone so I can add a link for adjusting your TPS, RREs  Eclipse 2G Turbo 1G Throttle Body Swap Ignore most of the article since you aren't switching throttle bodies, the adjustment procedure is near the bottom. If you need further help you can do a quick search of this forum for more information.

 

[transdude]

That is why I did it the hard way the first time. It definitely is an issue that I wish was resolvable. Sometimes vfaq information is outdated/wrong but since it is a worthwhile site it is hard to tell people that there are problems and still get newbs to go there.

Perhaps when I get some time I'll add a tech thread to the site about the many small issues with automatic transmission installs, failures, and quirks just to have another resource to send people to for help. As far as I know there isn't an easy resource that covers common little things like making sure the torque converter is about 3/4 of an inch into the bell housing when installing or how to change the transmission pump when you fail to make sure that happens as well as updated instructions that don't suck on installing the translab kit. Even the vfaq for end clutch install isn't very good and suggests a silly way to compress the clutch while adding unnecessary complexity to the process.

FWIW also I'm glad to see you back being active on this forum, perhaps you never really left but I see you around in more threads now and your expertise is incredibly welcome here.

Finally, perhaps this is better for PM but I'll just put it here, do you by chance buy valve bodies and/or broken transmissions? I'm likely to put one good one together out of the three I have but there will still be two cores with varying amounts of damage just taking up space in my garage when I'm done. I could purchase some rebuild kits but it is more investment for less return than I would like when I'm strapped for funds going into a new semester.

@definitiveno, I'm no longer posting from my phone so I can add a link for adjusting your TPS, RREs# Eclipse 2G Turbo 1G Throttle Body Swap Ignore most of the article since you aren't switching throttle bodies, the adjustment procedure is near the bottom. If you need further help you can do a quick search of this forum for more information.

This might save you some trouble on a least one tech thread, you can repost it where you think that it is appropriate:

Transmission and Torque Converter Installation Instructions

IPT Performance Transmissions

Torque converter and transmission installation is not always as easy as it looks. The vast majority of transmission and converter warranty issues are directly traceable to incorrect installation. Damage resulting from incorrect installation will void your warranty!
We strongly recommend that you read and follow these instructions.

Step 1:
Once the converter is removed from its box take a moment to verify that it is correct for the application. To do this, hold the converter up to the flexplate to verify that the bolt pattern is correct and also that the converter pilot fits properly into the rear of the crankshaft with no excessive clearance. It is sometimes necessary to remove any paint from the converter pilot with a piece of sandpaper.

Step 2:
Check the flexplate for cracks or excessive wear on the starter teeth. Also make sure that the two alignment dowels are in the back of the engine block. Make sure that the dowel pins and the holes that they fit in the transmission are free of corrosion and are lubricated slightly.
Concentricity of the converter and transmission to crankshaft centerline is extremely critical. Missing dowels and cracked or bent flexplates normally result in transmission and / or converter failure in a very short period of time.

Step 3:
Flush transmission cooler in both directions. Aerosol products made specifically for this purpose are available through us and other sources. When finished, make sure that all traces of flush product are removed from transmission cooler by blowing through with compressed air.
This step is mandatory and must not be skipped! Contamination dislodged from your transmission cooler can cause immediate damage to the transmission and torque converter and will void your warranty.

Step 4:
Converter must have at least one quart of the correct ATF for the application added to it before installation. This can sometimes take a little while so be patient.

Step 5:
Lubricate the converter hub and lock up o ring (if so equipped) with a small amount of transmission assembly lube, Vaseline or equivalent.

Step 6:
Install the torque converter into the transmission, being careful not to damage the front seal or pump bushing. Once the converter begins to engage the pump, hold the pilot of the converter with one hand to center the converter as best you can. At the same time, rotate the converter in a clockwise direction. This will allow the splines and hub tabs or slots to engage the pump correctly.
You will hear and feel two or three distinct drops of the converter into the transmission before it is all the way in. If you are unsure please contact us. If the converter isn't properly engaged in this manner, immediate damage will occur upon starting the engine.

Step 7:
Locate the transmission onto the engine dowel pins and install transmission mounting bolts. The transmission should contact the engine block squarely. If it does not, find out why- do not attempt to draw the transmission to the engine block with the bolts!

Step 8:
After the bell housing bolts are tight, the converter must rotate freely. Push the converter into the transmission as far as possible- there must be clearance between the converter and flexplate at this point!

Step 9:
Install torque converter bolts, using Red Loctite or equivalent and torque to specification. If bolts were supplied with your torque converter be sure to use them.

Step 10:
Finish installation of the transmission. When finished, add 4 quarts of ATF and start the engine- now add 2-3 more quarts immediately.
Additional fluid can now be added until the transmission reads 'full' on the dipstick. (In Mitsubishi and Chrysler vehicles it is necessary to fill the transmission and check the level with the shifter in Neutral- not Park). Please contact us if you need to know the approximate capacity of the transmission that you are working with.

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[nek]

I know this thread is old as dirt, but my transmission has similar symptoms. When I get on the throttle it will downshift, when Im rolling to a stop, it will down shift.
But when Im going up a hill, it tries its hardest not to downshift. Is there something on this cars that controls downshift based on load? I end up just dropping it into second to tackle the steep hills. Thanks!