[Andrewdrazin]

im at a lost,
i have a 91 240sx with a rebuilt ka24de.
when started, idle jumps to 2k rpm for about 3-10 seconds and than will bog down. at any time i hit the throttle it will try or it will die immediatly.
things i have tried or replaced.

1. checked timing, and distributor(used manual to verify tdc). installed new cap, rotor, plugs(gaped at 0.045), and wires.

2. checked vacuum leaks. when motor was rebuilt i replaced all vacuum hose/lines. cleaned IACV. checked for leaks with carb cleaner around the hole intake, none found. hooked up vacuum gauge and at idle of 2k it shows 15 IN HG, when the throttle opens the gauge jumps to 0.

3. checked fuel. installed remanufactured injectors 270cc, fuel regulator, fuel filter. checked and verified incoming fuel was on the correct line for the fuel rail. checked fuel pressure, pressure is at 30psi. i can here fuel pump prim too.

4. installed new TPS and set with a voltmeter to 4.80. installed new knock sensor. new battery. tried new MAF (from O'reillys). tried a different coil. checked grounds. new temp sensor.

5. checked ecu for codes. all i get is 55.

any other suggestions would be vary help full to me. thanks for reading