Limp mode 4.0

[Shturman]

My 4.0 feels like it is in limp mode, it’s a 4.0 manual swap and I did lifters in it and it starts and idles what seems okay but it’ll jump up and then shut off, but also driving it feels low on power, and will what seems like redline at 2.5k it just stops accelerating and sounds like it’s on redline but it’s only 2.5k, tach is fine and okay but I need some help, could it be not getting fuel correctly or?

 

[Dilligaf1]

Codes? IDK Crank Position Sensor or cam synchro maybe? More data is really needed before anyone could really diagnose anything. Running rich or lean? What was swapped engine, trans, both? Computer correct? Computer caps leaking?

I had a different vehicle that did something similar and it ended up being a cam position sensor. No codes, no power, completely give up at 3.5K. I've also seen VSS cause something similar, ecu was limiting throttle because it thought the vehicle wasn't moving, but I don't think your gen 4 ecu is that smart.