Auto transmission sluggish and shifts whenever it wants, NO CODES

[Jarnutt]

I searched and searched for the last week and haven't found a problem that sounds like mine that has had a solution yet. This is my first post, I'm not new to turbo or import tuning, but this IS my first DSM, and the automatic transmission and AWD might be a bit much for me to tackle alone. My problem is that the car drives fine at highway speeds, downshifts hard from a 45mph roll and hauls ass when you punch it WOT. HOWEVER, it drags ass on the bottom end, the previous owner chalked it up to turbo lag since its a stock turbo and a huge front mount with an automatic. The best I can describe it, it its like accelerating with the Ebrake pulled, and then suddenly it takes off like a rocket about 30 or 40mph. From a roll it sometimes decides to shift into second gear right after you start moving, if I choose to shift it manually (L to 2 to D), it will still drag ass to get moving, sometimes, other times it takes off fine and shifts fine, even under part throttle, normal driving, it sometimes shifts at the normal shift points, or it will out of nowhere decide to shift into second at about 10 mph and then 3rd at about 20mph. Overdrive works perfectly fine, and I don't feel or see the tranny slipping at all, the engine doesn't rev up, it just drags ass to get up there, and I'm fully boosted the whole time, its literally like having the E brake pulled. Also I've noticed that when it DOES decide to drive normally (ish) under part throttle acceleration from a light or stop, I feel it surging a bit, almost like its pulling timing or like someone was pulling on the E brake softly, I'm familiar with that feeling from my other turbo car when the boost solonoid went bad it kept pulling boost and the car would kind of lunge under part throttle. I have no codes in either the ecu or tcu, just a steady short pulse, its pissing me off. I'm clueless to DSM cars as far as their quirks go, but any help would be greatly appreciated. We pulled the pan to change the leaky gasket when the new motor went in, as the stock motor had thrown a rod, and there is no metal at all in the transmission, fluid is clean and red, and flushed it anyways. I had never driven this car until the new motor went in, so I dont know if the blown motor had the same issues or not.

 

[97gsxturbo97]

I think my post was misinterpreted. The trans definately isnt slipping. When I accelerate onto the highway when I give it about 50% throttle at 2500 rpm it will feel like all power is being lost. The rpms will jump sometimes as if the car is losing and regaining power. Like timing is being pulled? It only does this at that particular rpm and that particular throttle position. Also about the car not downshifting unless you come to a complete crawl, its kind of annoying how I have to boost the hell out of the t25 to go so I dont get killed pulling out onto a busy intersection. Or I just drop it into second so I can get out of the way faster but I shouldnt have to do that.

 

[the_mork]

Get a logger and check for knock.

 

[Jarnutt]

Yeah I did misread, sorry, sounds like you're having a similar problem to me actually, except mine is happening in 1st and 2nd, its almost like timing is being yanked and the car tugs back like the ebrake was yanked and then released all of a sudden. I don't see a fluctuation in boost, but I don't get any more power pushing it to the floor either, yours seems to be just 2500 rpm and 50% throttle, mine is any rpm range any throttle position, AND its intermittent at that, sometimes it goes days without doing it..

As for downshifting, if you turn a corner and it stats in 3rd or 2nd, and doesn't downshift even when giving it a healthy amound of throttle, that may be TPS or your TCU, if not possibly your valvebody sticking. TPS should tell the tcu to downshift because you want to accelerate faster than the current gear is allowing, however, the tcu also should also know if its getting that input from the tps. Another possibility, is the TCU not "learning" your driving habits properly, I've read in my DSM shop manual, as well as on here on the forum, that the TCU learns your driving habits and changes the shifting and downshifting points to accommodate a heavy or light foot, lots of stop and go or lots of high speed cruising. I don't know that the changes are THAT noticeable however, I sure as hell never noticed, id throw a meter on your TPS and verify you don't have any dead spots or odd readings, or just swap it anyways, should always have an extra anyways. Keep us posted on what you find, it might help me find my "loss of power" issue as well.

 

[joyfil2001]

I have had sluggish problems from day one. I put a rebuilt trans in the car and still have the same problems. I finally installed dsmlink and it looks like the timing is way off. Don't know how it is possible, but hopefully a tune will help. Anyone know where I can get a decent TCU to try?

 

[Jarnutt]

I would check the classified section here. ive already found a few TCUs but none for an AWD, i know alot of people say you can use this with that and this one interchanges with that one, but Id like it to br from the same car to avoid any other potential problems id be facing. besides, the shift points are different on other models, and who wants an AWD turbo that shifts like an N/A RS or GS

 

[jimmythesaint]

I by no means want to give the impression that I hate 5 speeds, I just don't like shifting everytime I go driving. Both transmissions have strong points, they are both highly likely to break when you beat on them, but people pay more for cars with autos for a reason, comfort, and laziness, like me ...

The DSM community is the only one I've been a part of, besides the buick and SY/TY, that knows the value of a well built auto.

My best friend had a 1g automatic awd that ran 11's back in 2003. The transmission was stock with new end clutches, shift kit, and a aftermarket torque convertor. His personalized license plate was 2LZ2SHFT

 

[Jarnutt]

HAHAHAHAHAA THAT'S RAD! Wish I was that creative

 

[Jarnutt]

So here is an updated history on my unsolved mystery. Its now a month and 1000 miles later, and still haven't got this bi*** figured out. I've replaced the turbo and manifold, I replaced the end clutches with IPT ones, I've replaced the valve body with an IPT rebuilt, replaced the filter, I've replaced the ECU with a 97 TSi AWD, I've installed a temp gauge and probe in the pan to monitor temp (which never seems to get much above 150 degrees), my fluid level hot in neutral is just above the full line, and still, it sometimes drags when accelerating hard, and after shifting to 2nd shifts right to third most of the time. One more thing I noticed, it seems like my torque converter is locking, even at very low speeds. The other day I noticed it shifted to OD at about 40 mph, and as the revs slowly creeped up to about 60 mph, I noticed that the TC never locked, because the sonofabitch was already locked at 40 mph. If I'm cruising 65 on the highway and give it some throttle, it accelerates with the TC locked, unless I push it to the floor, then it downshifts once for a second to what feels like 3rd, but then downshifts again to what feelsl like 2nd? I know this isn't right, but it acts like it downshifts at WOT to one gear, then immediatly to the next lower, instead of going straight to that accelerating gear. Again, this might be normal, because other than the lag of time for the downshift, it downshifts solid and pulls hard.

I've made some observations though, when in park, I get a rattling noise when you rev the motor up, almost like a broken rocker arm or spring, coming from what I thought was the head, but after inspecting, found that it came from my auto tranny, but the noise goes away completely when the car is in neutral or drive. Also, the dipstick tube for the tranny makes a loud sucking noise (with the stick out) when in park, but not neutral or forward or reverse gears. I don't know if that normal or not. Also, since I put in the new turbo, it seems to stall to 2900 rpm no problem now, but my brakes can't hold the car back anymore, so the car creeps forward, I gained some power puting in a non grenaded turbo, and at the same time found my brakes are inadequate. It drives a lot, and I mean A LOT better now with the valve body and it seems especially since the turbo went in it started driving even better, but I'm still shifting funny and lagging sometimes.

Not to change the subject, but with this new turbo I found something else odd. The old turbo was dead, completely, cracked to hell on the exhaust side, and contact on the compressor and housing, but when it boosted it was a solid 11psi all the time, with this rebuilt T25, it pulls harder and spools faster, but it boosts to 14 or so and then drops back to 8 or 9, and then changes during shifts, but always comes back down to 8 or 9. Even at part throttle I'm getting 8 or 9 psi, I'm still running the stock BCS, nothing manual or adjustable, I'm just letting the stock wastegate do the work for me. I found that odd that a better driving rebuilt turbo would change so much on psi between shifts and driving, but the tired ass one held 11 psi solid.

Thoughts or help on the tranny would be great. I'm still convinced this is an electrical issue somewhere, since the car drives like a raped ape at WOT, and downshifts hard and revs solid, shifts solid and quick at WOT, but drives like butt sometimes just putting around town. Doesn't matter hot or cold, I could be driving it for hours, and it may not do anything, even in stop and go traffic, and then shut it off, then start it back up and ill have problems, then, like magic, they go away.

 

[Jarnutt]

Seriously? Nobody has anymore input? This is killing me!

 

[joyfil2001]

I know how you feel. We get no love. I still have my sluggish problem also, and haven't been able to tune it out. It's so frustrating.

 

[Jarnutt]

The sluggishness doesn't seem to be worse or better even in this cold ass weather we have had lately. The noise the trans makes in park has been a bit of concern for me however. The dipstick tube making that hissing or sucking sound in park but in no other gears, including nuetral, has be scratching my head a bit. I've been shifting up through 1st to OD manually lately and noticed it slides into second on a bit of a delay, but even though it shifts to second slowly, it still pulls forward hard while its shifting, I would imagine if it was "slipping" the car wouldn't pull hard between shifts, also I've noticed the rpms raise a bit sometimes between 3rd and OD, not so much slip either, they just raise up about 200 or 300 RPM before dropping down between shifting 3rd to OD. All of this is, again, only sometimes. Its almost like it doesn't have enough line pressure or maybe a bad speed or tps signal. I'm going to try a tps next, and after that, line pressure mod if the 2g has a blue wire mod like the 1g.

Everyone is quick to just say "needs a rebuild" it seems. Rebuilding it wouldn't be a bad idea, but I honestly don't think its the clutches and bands. MAYBE, and I do mean MAYBE the pump is on its way out, but the clutches and bands are holding, the fluid isn't burning, and if it DID need a rebuild, this would be something that I would be having a problem with ALL THE TIME. I've driven autos that need rebuilds, they don't have the grab power that my trans does, even when its shifting funky, the RPMS never get away from how the engine pulls, if its revving, the car is pulling forward, there's no slipping and losss of acceleration, when it drags down like it does sometimes, the engine loads up, and rpms drop as well as it loads down the engine, like the TC is locking in 2nd. Come to think of it, that's EXACTLY how it drives, like the TC locks in 2nd gear. It shifts into OD sometimes at about 35mph or 40, and the tc locks right away, and my rpms drag slooooowly with speed up to about 60 without downshifting.

All I want is to figure it out, if someone else like me is following this thread, having similar problems, all they want is something to go by as well, just one small ray of hope that its not as complicated as I have made it so far. That's the point of the forums after all, to find solutions and share them, rather than bi*** about it.

 

[97gsxturbo97]

I am still pretty much having the exact same probems as you. The car shifts awesome it just lags when cruising. This is probably just how it was designed. My car only has 56,000 miles and I am positive it is not a clutch/bands issue. i will be changing the fluid/filter with OEM stuff soon. I was told these transmissions do not like anything but OEM Stuff. SOmetimes when I pull away from a slow stop I have to manually shift into 2nd so I can accelerate faster, otherwise I have to boost 15 psi and waste gas to move. The car shifts really early also. 4th at 30 mph accelerating at 2000 rpms slows the car down.

 

[joyfil2001]

I have rebuilt my tranny. It still has the same issue. What ECU do you have? 5speed or AUTO? It's gotta be a problem with the tune

 

[RoLinLine]

Well, as i read through this post i am having something similar. However i have DSM Link v3. Would it make a big difference swapping auto ECU with Manual ECU? Would this potentially cause problems? When i bought the ECU to get V3 installed on it i didnt ask if it was from a manual or auto, I do know that it is from a 1995 Turbo Eclipse. I have End Clutches and a shift Kit That i have not installed yet. I might try to tackle one at a time this weekend to see if it makes a difference. thanks for any advice you guys can give me and i am curious as to whether or not this has been resolved.

 

[knochgoon24]

I've traced my problem down to something with the TCU. If I stop, turn the car off then back on, the problem goes away. I should probably take the TCU out and check it, or get another TCU and see if the problems come back at all. It's cold and I'm a bit lazy (seems to be the focus of this thread).

I have the shift kit, new filter, and new trans fluid all set to go in here in a few weeks when I have some time off.

And the ECU doesn't even talk to the TCU that much. There's something with a "torque kickdown" that drops the idle when in gear so the engine isn't lugging against the transmission as hard, but that's about it. I'm actually running and ECU out of an Evo 8.

There's also a difference in the tune between 1g autos and manuals. I don't remember the specifics.

 

[steve]

2Gs use the same ECU in the automatic and manual cars.

I haven't looks at the 2G TCU but the 1G TCUs use the same leaking caps as found in the ECU.
Once the capacitor starts leaking there is a good chance it will kill, like unrepairable kill, the TCU so you want to make sure to check and replace before it's a problem.

The TCU doesn't tell the ECU to drop the idle. The ECU sees the inhibitor switch to know when the transmission is shifted from park/neutral into or out of gear. That what the ECU uses for idle. The TCU does tell the ECU that it wants to shift and requests that the ECU reduce the engine torque via the communications over the three pins 7 and 43 and 46.

 

[Jarnutt]

Well here is my step by step rundown. I bought the car fro.m a friend of mine in his 50s, he always thought it was sluggish because it was an auto awd with a t25 and a big fmic, so a mix of turbo lag and auto trans, compared to his built t28 with 550ls and a 5 speed. I bought it, drove it home, and the only thing I noticed was that a couple times on the way home, it downshifted so hard that it chirped the tires coming to a stop a few times, then as the weeks went by, that went away, and the sluggish lagging take offs became noticable.

I bought an ipt valvebody and dropped it in, in the process, the battery dies, I complete the install, charge my battery, and drive. Immediatly I notice that it stalls to 3100 and starts pulling hard, shifting firm, where as before the car would sometimes stall to 2100, sometimes 3000, sometimes 2800 and then it would start bogging back down to 2100 under full throttle stall. But after I drove for a few days, old problem came back, son of a bi*** I thought to myself.

So I did the end clutches, for no reason other than the fact that they are super cheap, disconnected the battery, left it like that for a couple days, again, it went back to driving like normal, for a bit. So I buy a TCU, thinking it would be a TCU cap or something that went back to normal after it sat discharged for a period of time. New TCU worked great, for a few hours, then the problem came back. Dammit.

So I THEN thought, ok, ECU problem possibly, so I borrowed my buddies 98 manual gst ECU. Again, worked awesome on the drive home, then, problem came back, also, a 98 convertible has an evap purge solenoid in the tank, so I kept getting a CEL on the damn solenoid, but other than that, same trans issue.

I've figured out, when I discharge the ECU and TCU for a few hours, the car drives ok for a bit, then goes to shit again, its no so terrible that I can't drive it, but its frustrating not knowing what is causing it. I have noticed what exactly is happening to my trans while driving, but can't figure out what's causing it. It seems to skip past 2nd gear, or shift into 2nd briefly then right into 3rd after about 3 seconds, UNLESS its WOT, if I'm on it hard, it shifts redline every gear. If I'm on the freeway doing 65, if I hammer the throttle, it first shifts down to 3rd, then after a second it shifts down the 2nd gear, like it should have when I first hammered the throttle, so downshift is slow from OD, also, if i turn off O/D and am in 3rd, and hammer the throttle, it shifts down to second hard as shit and runs like a raped ape, like I would expect it to.

Now manually shifting up 1st through O/D, it seems to shift slowly to 2nd, but shifts hard and firm to 3rd, and then slow into OD, the revs come up a bit, not like a slip, just like a slow transition, sometimes, it doesn't shift slowly all the time. I'm thinking its my TC, because I've noticed sometimes it locks, I mean LOCKS into overdrive at 45, WHILE I'M ACCELERATING, so now I'm trying to 50% throttle accelerate at like 1500 rpm hahaha, something is telling the TC to lock prematurely, but its not the TCU or ECU, because those are already replaced, and the valvebody was replaced with an IPT one, which comes with new solenoids.

So that's my issue, I'm still having it, but not letting it bother me too much, my fluids not burning, and according to my trans temp gauge, I never see temps over 160. Any thoughts on that?

Possibly unrelated, or maybe it is, I've noticed a noise when at idle coming from what I THOUGHT was the valves a feww months back, its a kind of rattling noise, nothing too terrible, at first I thought I had a broken keeper, or collapsed lifter, if you can imagine that sound, turns out the noise dissapeared when I switched the trans to neutral, or put it in gear, it only does it in park, and it gets worse with revs, really loud and buzzing around 3k or 3200 rpm, but vanished like magic in nuetral, also, the dipstick tube makes a loud sucking, almost hissing noise in park with the dipstick pulled out, but it dissapears as well in neutral. That may be normal but the buzzing can't be.

 

[97Bstd420]

I am starting a build soon on a A/T I will keep you posted just because we both have the same issues with the tranny. Keep us posted and i will chime in my findings

 

[joyfil2001]

I haven't figured it out yet either. But now I can get it to brake boost and launch no problem. It is just the 1st gear take off that is so slow.

 

[Jarnutt]

All my problems are hit or miss, I cant ever duplicate them when I want, but in my mind it seems like its doing that shit all the time. Cold start first thing in the morning its a DOG, I mean it is sluuuuugish, almost like the Ebrake is on, then once it hits 3k, takes off like a damn rocket. The car is driving so inconsistent, its quite aggravating at times, but, it still DRIVES none the less, its dependable, and I just wish I could get the gremlin figured out, and for that matter, I hope everyone else here does too, nobody should have to drive a busted ass car.

Everyone I talk to keeps telling me it needs a rebuild, but Im an effing mechanic, I know as well as anyone else with a bit of mechanical knowledge, that if it needs a rebuild, it wont sometimes drive perfectly fine when the fluid is 165, or 180, it will drive WORSE, heat makes any bad trans worse, heat doesnt seem to be a factor on when mine acts up, its just at random, and at that, a trans that needs a rebuild wont shift solid and fine sometimes, it wont shift fine at all, because its mechanically worn. Am I wrong to assume this? I mean, if an engine needs a rebuild, your rings dont SOMETIMES seal right, and your crank doesnt SOMETIMES stop walking HAHAHA

Is there a way to isolate the operation of my TC? I know theres a red wire that operated the TCC solenoid, but is there any way to monitor what its doing? I think its locking at random, and in low gears, and thats stemming some of my issues.

 

[Jarnutt]

I cut the red wire and put a plug between the two cut ends just to test it out. It stopped the locking of the TC, but it still has that sluggish feeling, sometimes, Even at WOT in frist gear, and it seems like ONLY in first gear. It is also still shifts into second, and then immediately into 3rd unless Im WOT.

 

[the_mork]

Check your tune, my car used to be (and sometimes still is) sluggish on a cold start but it ended up being that I had issues with my tune pulling me out of some cold start protocols. After adjusting my timing and cold start tables I had a much more streetable car during warmup. I'm aware that using an SAFC you are somewhat limited with control over those issues but it may be a place to start.

 

[DSM_Roller]

bookmarking

 

[Jarnutt]

Check your tune, my car used to be (and sometimes still is) sluggish on a cold start but it ended up being that I had issues with my tune pulling me out of some cold start protocols. After adjusting my timing and cold start tables I had a much more streetable car during warmup. I'm aware that using an SAFC you are somewhat limited with control over those issues but it may be a place to start.

Id agree IF I were using a fuel map. Im just using it to basically watch the pretty blue lights, I dont have a wideband yet, so I dont see any point in running a map.

 

[joyfil2001]

Check your tune, my car used to be (and sometimes still is) sluggish on a cold start but it ended up being that I had issues with my tune pulling me out of some cold start protocols. After adjusting my timing and cold start tables I had a much more streetable car during warmup. I'm aware that using an SAFC you are somewhat limited with control over those issues but it may be a place to start.

How do you adjust the cold start tables? I have link.