I've done quite a few Ls swaps , segment swaps , with no issues , so this one has be baffled .
Its a Lq4 , 4l80e and a P59 ALL FROM THE SAME 05 EXPRESS VAN no segment swap needed . Should be a drop in and go...Its all in a 70 Nova now , should be a super easy swap... It will only shift manually 1st and 2nd gear , when you engage 3rd it just stays in second and no overdrive as well . Reverse is there just fine . If you put it in auto and throttle up it never gets out of 1st gear . Heres the thing...Its not the trans , I was fortunate enough to have 3 working units in the shop and have no checked with all 3 and it does the same thing . Also...It does have a B&M pro stick but I've run it with and without the linkage on it , with leaving it in 3rd or (Drive) . So I would tbink that rules out the linkage . I have the Tcc brake switch wired as well so that works or should be working , and NO trans codes , I do have a typical po103 , and there's an issue with the alternator wiring , some code regarding field current . it charges but I need to hook my generator light to it I believe to lower my charge rate , its at 14.9volts...OK so I hope someone has some insight Im really lost on this one , Really need help figuring out whats wrong ??? I have to think its the tune but ive played with different tune files for the 80e as well...