So heres my problem my car dosent seem to want to shift from 2nd to 3rd at WOT. The fluid is full and a nice ruby red. It doesnt seem like the transmission has trouble shifting. Its more like it doesnt know when to. Down the track it wont shift until it bounce off the rev limmiter around 6500. I hope this isnt my trans going or the 2-3 shift solenoid. Could it be that the car want retuned with the stall or maybe my shift point is to high? Do i have no hope and need a new trans ? i hope not if so the DRs come off and im retired from the track for awhile. Shifts awsome from 1-2 and even 2-3 on the street. Seems like its only at the track or from dead stop the 2-3 shift as a problem. Thanks for help.

 

Well the first thing to do is to determine when the shift is actually being commanded and then determine of thees enough time allowed from command to actual shift and the rev limiter. In many cases The shift command is given to late for the trans to complete it before the limiter.

 

I recently had a customer that had an issue similar to yours. This issue was with the 98 pcm and tuning is what fixed it. I believe it had something to do with the TPS settings in the tune IIRC. Vince

 

so with a tuner i should be able to fix this problem? Even if the shift is being commanded to late?

Thanks

 

Yes you should , I also recently had and individual calling me asking about a similar issue with a chronic problem like this and no matter how low he set the shift time its would still hit the limiter, But he called back and oddly he found the solution, Not being a tuner I dont know what the full affect of this would be but he said he solved it by turning off "kickdown" But according to him the car would still kick down under throttle. But I thought it was interesting since I hadn't heard of that yet.

 

Ill have to look into it. Im buying hp tuners this week so i can check everything out and start data loggin my passes. Thanks for all the help im feeling alot better about this situation. I forgot to memntion sometimes down the track from the 2-3 shift. It will up shift, downshift, and the upshift back into 3rd?

 

Thats sounds like some odd tuning issue there for sure

 

Yeah thats what first came to my mind when it happend. When i bought the car i was told it was dyno tuned from TT perfromance. I belive the kid that it was but not sure and what work was done before and after the tune. I have a feeling the tune was before the converter and the gears. But thanks again for the help

 

In addition to taking a long look at the Tune... I would highly recommend starting with replacing the Vehicle Speed Sensor. Chances are it is quite a few years old.

I have built new units and had them not make the 2/3 upshift at WOT, done some data logging to determine the cause and found that the VSS was faulty. But, in times when that occurred it was not reported by the PCM as being defective. I have even gone so far as to install a know bad sensor in a car that performed flawlessly and found out that the 2nd PCM did not report it as being defective. Part was out of a '98 and was installed in an '01 car. It was very, very apparent that this sensor was defective when it was logged. Installed a new sensor, made no tune corrections and the car rocked!

Hope that helps.

g

 

wow that may be it cuase my car is throwing no codes but doesnt seem to be running what it should be at the track. I think some other stuff besides the trans is holding my car back. Ill def replace that and check the tune out. Hopefully after that my car can start putting down some low 12s. My speedo is off because of my gears but this would not effect my pcm reading in any way would it? I really dont think it does but i could be wrong.

 

Hmmm... when the gears were swapped, did you have the tune adjusted to reflect the new ratio?

g

 

no i dont im buying a tuner but held off casue i didnt think that would really mess with anything besides me reading the speedo

 

Anytime you change the rear axle gear ratio you must change the tune to reflect the modification. If not, the transmission shift timing will be incorrect.

g

 

well then theres my problem 1-2 shift fine but i guess its not commanding a shift due to the gear change from 2-3. that would make perfect sense. I bought the car with all the mods done. The only reason i know the tune was done without the gears is cause my speedo is off. not to bad around 30 but up near where my car would shift 2-3 it is. Thanks alot for the help maybe now i can get this all worked out. Problems with buying a modded car.

 

The faster you go the bigger the error for that is going to be.

 

Think that error is enough to take a .5 to .8 off the 1/4 E.T

 

Glad to be of assistance.

Make sure to record the changes that are made to the tune for your own personal reference. Some tuners will provide this, some won't. None will if you do not ask for a detailed list of changes.

Be sure to get back with us once you have it ironed out. It could prove to be useful for another enthusiast down the road.

g