I'd first suspect a "tune" issue.
Did your tune guy possibly move the WOT shift points higher without changing the rev limiter? Or did he move the rev limit enough?
With more than stock power to weight, acceleration will be quicker, trans shift lag will be longer (rpm-wise), and you need a bigger delta between the WOT shift points and the fuel cutoff.

 

If your tune is okay, then its probably your accumulator inside the transmission.

 

Your best bet is to drop the pan, and you'll see the accumulator next the valve body. Its a big silver housing with 3 bolts ( If i remember correctly ) Take the bolts out, pull the housing down and check the spring, and piston itself. You can buy the entire assembly for 30$ .

 

Fixed. Changed out the accumulator. Shifts crisp right at the limiter--runs great!

 

Your welcome Glad I could help.

 

I know next to nothing 'bout automatics. But thats one cool Willys. Awesome dude.:LS1LT1flag:

 

Thanks!

 

nice project

with a mildly built '95 Z28 LT1/4L60E combo (LT4 Hotcam, Comp ProMag RR, Chrane springs, fresh rings and bearings, headers/2 1/2" exhaust without cats, CAI, etc). Had a mild dyno tune and turned off rear O2 sensors and slapped in a 3.73 posi in the diff.

something is wrong with those numbers; you can't turn off the rear o2 sensors on a car that never had any (or inputs or code for them). that is, unless someone put a 96+ OBD-II ecm in it for some reason?

 

nice project



something is wrong with those numbers; you can't turn off the rear o2 sensors on a car that never had any (or inputs or code for them). that is, unless someone put a 96+ OBD-II ecm in it for some reason?

You're right--guess I was thinking about my later model OBDII equipped Mustang that we took the cats off of and had the rear O2's turned off in the tune... nice catch BTW!

 

It is a bastard though--the motor is out of a '95 Z28, the computer and tranny came out of a '96 Buick Roadmaster. Not to mention the '94 S-10 chassis, '50 Willys body and Porsche Recaro buckets out of an older 911! Somehow it all comes together and works...

 

so it is an OBD-II ecm, then. that's important to know when tuning/diagnosing.

 

hmm does your knock sensor even work? (are you running a second knock sensor?)

the roadmaster ecm, bin, and filter module are afaik designed for twin knock sensors

 

This is where it gets complicated--The longblock is from the '95 Z28--everything else is from the '96 Roadmaster (or so I thought). It is not an OBDII--the motor, tranny and I guess computer were changed out at some point with a drivetrain from a '94 Roadmaster--figured that out when the front to back custom wiring harness from Ron Francis would not fit and had to be modded (they were great to work with). Then it spun a rod bearing shortly after install so I procured the Z28 motor and had a basic overhaul with the addition of an LT4 Hotcam with Comp ProMag rockers, Chrane springs/retainers and mild head porting. Kept all the '94 Roadmaster Optispark, water pump, wiring, sensors, harnesses etc... is that clear as mud now?! Told you it was a bastard, a real junk yard dog. Just a very nice running bastard!
3300 lbs with 1/2 tank of gas, 3.73 posi rear, CAI, shorty ceramic coated headers, 2 1/2" custom exhaust with H-pipe and Magnaflows and no cats. I'm very pleased with how it runs/drives now--the only issue was the shifting problem and now that is fixed--me happy:banana:

 

thats a bit of a mix. you have an obd-i ecm and '94 trans, and non-vented opti, might as well call it a '94. just curious.

 

Guess that would be easier, Huh? Was just giving the long winded explanation since I had confused the issue by saying it came out of a '96 RM...

 

You should get us more pics of that "Bastard" , that thing is really cool . I've never seen anything like it.

 

I can do that...