4l60e works sometimes.....

[Darrenmb]

Ok, in case there are different readers in this section versus the engine or pcm section, heres a little background.. complete engine and drivetrain from a 94 pontiac formula, into an 83 jag xj6, motor has lt4 hotcam, springs and 1.6 rockers, and is tuned by Moe, not that any of the last bit matter, but laid it all out there just in case... motor looks like it was made to fit in the jags engine bay and car is a total beast, (when it decides to play nice)
Here is the issue... if i drive the car sedately its a dream, shifts fine everywhere, and pulls nicely, but, if i get into it, i have issues galore.
If i pull away from a stop aggressively, it will shudder then make a pop sound and all forward gears are gone and trans is making a rattling sound., if i put back in park, then back to drive, 9 times out of 10, its fine again, once in a while its not fine and has to sit a few before she will move.
If car is already moving and i push her hard, she will downshift hard, and make the pop, and again all forward gears are gone and shes rattling. ...
Before I tear it out and take to a shop, is there anything that jumps to mind that voild cause this? I used to be a mechanic 30 years ago, but was mostly engine and ac work, trans stuff we always farmed out!

Oh and torque converter is stock... and i never lose reverse!
If trans has to come out nows the time to do it while everything is slow, as i am stuck dealing with an issue in the UK and cannot get there, and due to time difference i can only call over there until noon out time!!!