I am a newbie so please don't flame me.
My son purchased a 1998 Z24 2.4ltr. It had a hole in the block so we purchased a used engine. I just finished up swapping the engines and am having some issues.
When i start the car it goes straight to 3-4k rpm. I have swapped the AIC, EGR, TPS. Nothing changes the rpm's. I have pulled the AIC to examine the pintle, it appears to be coming out all the way (.633) @5/8inch. If I unplug the AIC the rpm's increase to @5k. I have plugged the AIC port with a dowel and tape to ensure a good seal. No change. I have fabricated a shim plate for the EGR to check if I was leaking past. No change. The only thing I have recently discovered is that if I unplug the pressure sensor (+5v reference, out, and ground) from the throttle body the rpm's do drop to @900-1000 rpm's. But it runs like a$$, almost like it is missing real bad. I'm going to exchange the throttle body and change plugs after i get off work. Any other suggestions. I really need some help.

Thanks in advance-
Chris

Check vaccum lines, MAP sensor first.

It almost sounds like the car is sucking air really bad somewhere between the head and TB...

Are there any holes in the intake manifold or anything?

Thanks for the replies. I ended up swapping the TB and the intake manifold from the old engine. Also changed the EGR tube. I think the intake had a bad gasket. it runs like a clock now. Thanks y'all