346_chevelle

I'm having some issues with a swap I have done for a friend. It's a 4l60e with a transgo hd2 shift kit. My problem is intermittent the trans wants to take off in second when in any forward gear selection except 1st. I can command the trans to shift into 3rd and 4th and even lock up. I have double and triple checked the wiring from the PCM to the trans.

There is another issue with the transmission
At any speed above 60 mph the torque converter will lock and unlock repeatedly until you slow to 59 mph. If you put the transmission into 3rd the converter will lock up and stay locked like it should above 60. I'm running out of ideas and I'd appreciate any help.
Thanks

01ssreda4

iTrader: (96)

Any codes being thrown?

AnotherWs6

iTrader: (17)

Sub'd on this one. My stock 2000 Silverado has done the same thing forever, usually wants to start in second gear. Got a mail order tune but never mentioned it. Don't know if they could have fixed this but they didn't.

I have a feeling it's a pretty common thing, maybe something GM did on purpose. End result is that I drop the truck into first almost every time I come to a full stop. Second nature now.

mrvedit

Most important is to scan for codes, as mentioned.

Also, usually when people think the trans is starting in 2nd, it is really starting in 3rd which is "limp mode". Various codes will cause the PCM to start in 3rd.
Not sure of this, but perhaps even in limp mode, manual-1st will put the trans in 1st gear.

AnotherWs6

iTrader: (17)

Never threw a code. That might be OP's issue but not mine. Again, been doing it for years.

346_chevelle

That's the thing. I have yet to see the thing throw a code. Last night I didn't have my laptop with me to check but the other day on the dyno it did the same thing and it fixed itself somehow. When I left the dyno it started doing it again. I let the car sit over night and it worked fine the next day. So it's a 50/50 shot I can get in it and have all forward gears.