some quirks with the A/T...diagnosis help?

[navyblue2000]

A little background:
93 TSi AWD. Motor was recently swapped out for a rebuilt motor, a motor from an M/T, so it has the 450's, 14B, and manual cams. I didn't get to drive it very long with the A/T motor (the valves committed suicide and took some pistons with them), but I've noticed some things odd with the new motor in.

First off, the tranny has ~125,000 miles on it. THe mechanic at the place I had the motor put in told me I had "10-15000 miles left on it". He suggested a flush/fill, but I'm not so sure I should do it if it's having problems:

Somtimes it likes to surge, almost like the converter cant make up its mind to lock or not. the shifts aren't very crisp in power or eco mode, and it shifts WAY early into second gear in eco mode. It's kinda aggrivating to deal with in traffic, and it's a dog in the low end (I realize that will happen with the bigger turbo and cams, but I swear my fiance's GA16 powered A/T nissan sentra will take this thing till the turbo spools). it LOVES to hang right around 2000 rpms to, which I'll assume is close to the converter stall...but that just seems odd to me, how long it hangs around there, it's like the converter has to load up...if I punch it from a stop, i'll hang, hang, lag, lag ...... BOOOOOOSSSTTTT-HAAAA But it's really more annoying than anything.

anything that a flush and filter change will help? or some other way?

 

[91Bomb]

A little background:
93 TSi AWD. Motor was recently swapped out for a rebuilt motor, a motor from an M/T, so it has the 450's, 14B, and manual cams. I didn't get to drive it very long with the A/T motor (the valves committed suicide and took some pistons with them), but I've noticed some things odd with the new motor in.

First off, the tranny has ~125,000 miles on it. THe mechanic at the place I had the motor put in told me I had "10-15000 miles left on it". He suggested a flush/fill, but I'm not so sure I should do it if it's having problems:

Somtimes it likes to surge, almost like the converter cant make up its mind to lock or not. the shifts aren't very crisp in power or eco mode, and it shifts WAY early into second gear in eco mode. It's kinda aggrivating to deal with in traffic, and it's a dog in the low end (I realize that will happen with the bigger turbo and cams, but I swear my fiance's GA16 powered A/T nissan sentra will take this thing till the turbo spools). it LOVES to hang right around 2000 rpms to, which I'll assume is close to the converter stall...but that just seems odd to me, how long it hangs around there, it's like the converter has to load up...if I punch it from a stop, i'll hang, hang, lag, lag ...... BOOOOOOSSSTTTT-HAAAA But it's really more annoying than anything.

anything that a flush and filter change will help? or some other way?

I would go with the flush and filter change because you have nothing to lose and it might improve things enormously. While the filter is out check the ?adjusting screws? on the valve body that control the shift firmness. If the previous owner had trans work done at a place like SCaamco they most likely would've adjusted the ?line pressure? so the shifts would be softer. ( I had work done at aamco and they changed the shift characteristics so they were much softer because that is part of what they do). John from IPT told me to turn the adjusting screw in so that it's flush with the valve body and then back it out 2.5 turns to get it to where the factory had set it at -- I haven't tried this on my car yet. When my trans was factory stock it would chirp the tires on 1-2 shifts like it should -- even with new rubber

When in 'eco' mode it will upshift very early -- I can get into 4th gear by 20 mph if I want to when in 'eco' mode.

That Nissan Sentra would beat my '91 FWD A/T off the line too -- in fact I can't think of anything non-turbo that won't baat me off the line. There is nothing happening in those very low rpm's until the turbo starts to spool. The 7.8:1 compression ratio has something to do with it as does the fact that when the throttle plate opens there is a much bigger intake tract that needs to be pressurized as compared with a N/T set-up (At least I THINK the intake is an aggravating factor). As you mentioned you made the situation worse with the 14b and M/T cams. So, of course it's a dog off the line if you're not brake boosting, which BTW, I wouldn't reccomend with a stock trans that's not running 100%. You can try switching back to the A/T cams which will help the low end and even go back to the 13g if you don't plan on boostng too high but that sentra is still going to beat you off the line . But to me that's part of the fun -- letting the other guy think he's got you and then turbo spools up, tires start smoking, and as you roar past him you can sense his sh%t eating grin melt right off his face.

 

[Hummer]

A little background:
93 TSi AWD. Motor was recently swapped out for a rebuilt motor, a motor from an M/T, so it has the 450's, 14B, and manual cams.

It's kinda aggrivating to deal with in traffic, and it's a dog in the low end


Did you change over to a MT ECU? If not, you are running 450cc injector on a ECU with a 390cc injector fuel map, may be why it is "a dog in the low end", extra fuel?? Could the motor being load-up with fuel on the bottom end relate to your trans issues?

Bob