When starting the car, it rotates no more than twice and fires right off. Idle climbs to 2500-3000 but within 10 seconds it will quit unless you give it more gas and keep the revs up to 1500-2000. As soon as you let off the throttle the car will quit. I have had the upper intake off twice to verify that all of the vacuum lines are installed correctly. I used a silicone gasket as well as the paper one after the first removal as I wasn’t sure that the old gasket was still good and I can’t get parts locally. The bottom intake was installed with gaskets and silicone. I have checked the fuel pressure, and it is right on. The pump pressure is low at 57 psi and after 5 minutes it is low at 45 psi. Could this be the problem?
I also have lots of spark. In fact I can start the engine with just the lead or trail plugs connected.
I changed the ground strap on the engine and just to be sure added a second one.
The timing marks on the pulley were rusted and I was uncertain as to where the crank angle sensor was to go in. I used the "look in the rear plug holes mark the pulley and at the center point of these two marks should be TDC #1" technique. o I also placed a small rubber hose in the #1 plug hole after I saw the rotor enter the area and felt for TDC. The 2 marks I came up with were very close to each other so I am assuming that the timing is correct or very close

 

Open up the air bypass screw on the TB all the way and see if it will idle with the extra air flow. You can tighten the throttle cable as a temporary fix if you want it to idle even higher. Also, does the car still have the thermowax? If it does, does it idle at 1500 RPM when it's cold, but die when it tries to idle at 750 when warm?

Was the TPS taken off during your motor swap? Check that the top pin is at 1 Volt DC when warm and key is on.

 

Opening the air bypass (screw on the top of the dynamic chamber) has no effect. Trying to adjust it with the initial set coupler shorted also makes no difference.The thermowax is still in place. The TPS was not removed when I swapped parts andeverything was working before the swap except the engine.
If the idle drops below 1500, it just dies unless you give it more gas. This engine is acting like it has a big air leak, but as I said, I have pulled everything apart looking with no joy.
Any other suggestions?

 

have you checked your afm?

 

As I started to disassemble the air cleaner unit to get at the AFM, I tried to start the car with the hose from the air cleaner to the input removed. The car will not start. As soon as I put the hose back on it started but again would not stay running. Is that usual?