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Inconsistent 1-2 shift firmness


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As you can see in a previous post I've had doubts about the consistency of my 1-2 shifts since the installation of my Zippy shift kit. Sometimes it shifts relatively firm and other times it's relatively soft. I convinced that the tranny is in good shape because I keep pounding on it and it keeps shifting well. It's just that it reverts back to semi-shock like shifts (only on the 1-2) from time to time and other times it's pretty firm. The 2-3 and 3-4 shifts are always the same.

 

Thoughts anyone? :happysad:

 

Regards,

Dan

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you may want to check the billet servo's to see if you have broken the poodle clip on the intermediate.

 

Yes, the TM is completely disabled in the PCM and Zippy could you elaborate alittle more on which part I should have a look at?

 

Regards,

Dan

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This is me researching my problem and posting my thoughts for discussion:

 

I found this discussion on line pressure on LS1Tech and it helped me think of a different angle on my 1-2 shift problem. I noticed that my problem may be temperature related. What I mean by this is my engine heats up quickly but my tranny alway takes quite awhile 15-20 mins. to come up to full operating temperature on my guage. I then read the post by "The Guy in the 99TA" where he complains about 'bogging' at shift points.

 

Can high line pressures cause an engine to "bog" on shifts? I was told that with my set up that high line pressures that are in the FLP trannies could very well make my bolt on car bog when it shifts. When I say bog I don't mean like a 6 speed does off the line, its like the power of the car is almost shut down for a second.

 

Josh S.

       

The Guy in MY 99TA

 

gwj

TECH Fanatic

 

Josh S.

 

 

THAT sounds like torque management to me-or hitting the rev limiter. I know that when I first put the ST3500 TC in my car, it took a lot of time adjusting shift points/rev limit with the only tool I had - HPP3- to get acceptable shifting w/o bogging down.

I defer to those who know about line pressures, though.

(EDIT) I found that ATAP was not always accurately recording max rpm and I had to monitor just rpm and current gear over and over to determine I was hitting the rev limiter.

 

This 'bogging' sounds like exactly what I'm going through only after further study I've discovered it only does it when the tranny's cool or cold. Once my tranny is fully warm I get a 'firmer' shift.

 

Idea? When my tranny's not yet up to full opertating temperature my 1-2 shift is slightly delayed and I bump into my rev limiter? Is this causing the bog or softness I'm complaining about? Hmmmmmm..............thoughts anyone? :dunno:

 

Merry Christmas!

 

Dan

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The latest educated guess on my 1-2 shift problem is that on a cold tranny my 1-2 shift is delayed enough to bump into the rev limiter. This is causing 'soft shifts' or giving me the feeling that the engine is laying down for a second before it shifts to 2.

 

Based on some questions I've asked my 1-2 shift point is approximately 5650-5700 and my rev limiter is approximately 5900. Enough of a margin?

 

I am ordering a re-tuned PCM this week and I will keep the forum posted when I have some results.

 

Thanks to everyone for your help in this matter.

 

Regards,

Dan :D

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  • 1 month later...

Well the answer is in! Bryan (PCMForLess) adjustmented my 1-2 shift point and the throttle control limiter and I now have the proper WOT 1-2 shifts! :smash:

 

Apparently the 'rev limiter' was coming in as much as 200rpm early depending on tranny/engine temp.

 

Thanks again to Bryan.

 

Regards,

Dan

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  • 1 month later...
you may want to check the billet servo's to see if you have broken the poodle clip on the intermediate.

 

Yes, the TM is completely disabled in the PCM and Zippy could you elaborate alittle more on which part I should have a look at?

 

Regards,

Dan

anybody else know what this clip looks like? does it break or just come lose? If I wanted to check mine how hasrd would it be?

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