2005 Blazer ZR2 Vortec 5.3L swap

[Blazer_Boy]

Hey guys, Been around reading stuff quite a bit on here, Im in the midst of trying to figure out what is wrong with my motor.
Lets start with the basics.
Its a stock block 5.3L vortec from a 2003 Silverado auto truck.
Intake and 0411 ecm is from a 2002 avalanche dbc auto.
Installed a manual NV3500 Transmission.
I have not changed any of the parameters for the vss and gear ratio ect.
I have a Current performance wiring harness for the swap.
Heres my issue, at idle or or under load i cant get the motor past 1500 rpm.
If i bring the throttle up and hold it at 1500 its fine, if i try to go past and hold it it drops and bounces back up continually.
Im going to be looking at the tps soon here but aside from that, is there any chance abuse mode is causing this.

Thanks

[XDR]

Got a similar setup in my Jeep. Mine is a 01 5.3 with a 99 4.8 PCM, 24.8lb injectors. Here is my current tune that I'm working on, it is a SD mode tune but you can reference the tranny stuff, I have no vss input into my PCM either. I also have it backed with a NV3550 (similar to your tranny).

04242014 TJ Tune 5.3.hpt

[jcrumpley]

I have the same setup in my 1992 GMC, other than the motor being from a 2002. Do you have any dtc codes? Do you have your air intake and filter installed? Do you have the VSS wired to the NV3500? Do you have the stock tune in the ecm still?

[Blazer_Boy]

Thanks for the help! the vss is now installed, but i found the issue, Under engine abuse mode it was set to 1600 rpm, now what i cant figure out is why it is set in abuse mode, the vss is connected. I am having an issue though, my speed only shows up with the clutch depressed. for time being i incresed the abuse mode rpm limit. the stock ecm for the blazer is sitting in a box.