My 94 4.0 has a odd problem (no check engine light or codes) and I can't figure it out I just wanted to see if anyone has had this problem or could maybe help me out When I first start my truck it instantly starts surging (revs up and down) I have to put my foot lightly on the gas pedal for atleast 3 or 4 minutes to get it to stop I have put on 3 brand new throttle position sensors put on new maf Sensor also a new alternator new battery new battery cables new iac new intake manifold gaskets and replaced all vacuum lines on the engine my truck did this way before these parts have been installed also the truck trys to stall and starts jerking when I let off the gas (battery gauge bounces up and down when it does this) it only does this around 40 to 50mph could it be faulty wiring or possibly a bad fuel pump? It shifts fine and it doesn't act like it's going to stall or jerk all the time so I'm assuming it can't be the transmission and there's no sounds when it does it

 

Check for a gross vacuum leak.
The PCV system can become disconnected and would be such a leak.

 

I have a new pvc valve and new hoses installed I checked them and everything seems to be connected

 

I had to plug up 1 outlet on pcv body. And it fixed same issue. It was outer one towards drivers side.