jocko463
NAXJA Forum User
- Location
- Southeast USA
Okay, I know this subject has been beaten to a pulp.... and I've done some searching of this forum (and others) for some back ground info and trouble-shooting advice.
My '00 XJ, with the ubiquitous AW4 slush box, is stock with the exception of a DynoMax Turbo cat back system which I heartily recommend for any daily drivers out there....gotta nice burble without getting ugly sounding....sorry guys but American inline sixes sound like crap with most "performance" mufflers...just MHO. But I digress.....
So I scored a "home grown" bored 62mm TB off of eBay. The machine work was okay and the hard edges of the IAC and MAP ports where "softened" with a Dremel (apparently held by someone who's drinking way too much Starbucks) to eleiminate the whistle. The swap was easy and the first thing I noticed was the off idle "punch".... I also noticed a little more spunk on the interstate....these are good things.
What I also noticed, much to my dismay, was the AW4 wasn't shifting like it used to. Rather than a nice positive shift into each gear, the tranny was oooozing it's way through the gears and into OD and lock-up. What's up???? I'd never read of anyone having this problem. So I start trouble shooting.... the TPS being the prime suspect and the PCM/TCU computers possibly having to learn new habits. Checked the TPS (with an ohm meter) and it's in fine shape with a smooth, linear change in resistance. I reset the computer again and checked for any fault codes. All seemed okay but still the slushy shifting tranny.... so I put it all back to stock. Put the stock TB back on and... voila!... the tranny is shifting like she used to. And yes, I did check and adjust the TV cable in both cases.
Has anyone else experienced this problem? Anyone have any odd problems with removing the lower ridge in a stock unit? I have to wonder why DC designed the TB the way they did... the lower edge of the stock TB definitey creates more of a venturi effect....it's gotta be there for some reason. And after seeing that a fully bored TB (62mm) results in minimal 5HP/6.5ftlb gains, I think I may just stick with the stocker.
Mike
My '00 XJ, with the ubiquitous AW4 slush box, is stock with the exception of a DynoMax Turbo cat back system which I heartily recommend for any daily drivers out there....gotta nice burble without getting ugly sounding....sorry guys but American inline sixes sound like crap with most "performance" mufflers...just MHO. But I digress.....
So I scored a "home grown" bored 62mm TB off of eBay. The machine work was okay and the hard edges of the IAC and MAP ports where "softened" with a Dremel (apparently held by someone who's drinking way too much Starbucks) to eleiminate the whistle. The swap was easy and the first thing I noticed was the off idle "punch".... I also noticed a little more spunk on the interstate....these are good things.
What I also noticed, much to my dismay, was the AW4 wasn't shifting like it used to. Rather than a nice positive shift into each gear, the tranny was oooozing it's way through the gears and into OD and lock-up. What's up???? I'd never read of anyone having this problem. So I start trouble shooting.... the TPS being the prime suspect and the PCM/TCU computers possibly having to learn new habits. Checked the TPS (with an ohm meter) and it's in fine shape with a smooth, linear change in resistance. I reset the computer again and checked for any fault codes. All seemed okay but still the slushy shifting tranny.... so I put it all back to stock. Put the stock TB back on and... voila!... the tranny is shifting like she used to. And yes, I did check and adjust the TV cable in both cases.
Has anyone else experienced this problem? Anyone have any odd problems with removing the lower ridge in a stock unit? I have to wonder why DC designed the TB the way they did... the lower edge of the stock TB definitey creates more of a venturi effect....it's gotta be there for some reason. And after seeing that a fully bored TB (62mm) results in minimal 5HP/6.5ftlb gains, I think I may just stick with the stocker.
Mike