Idling At 500rpms, Sputtering, and Smoking.. Help!

[Codelicious]

I am having issues with my 89 240sx (ka24e). It fires right up but it is now all the sudden idling at about 500rpms, sputters, and is blowing out white smoking like crazy!

At first, I thought it was an injector because we unplugged it while the car was running and it didn't change anything at all. Now that I have replaced that I am still having the same issue. I can't seem to figure out what I should do next..

I did notice that if I pull out the Fuel Pump FUSE not the EGI Relay that the car starts to idle fine at about 900rpms and it also stops smoking. As soon as I put the fuse back in the car goes back to smoking and idling at 500rpms and sputters.

Here is a list of the things I have changed:
- MAF Sensor
- MAF plug
- TPS
- Injectors
- Tune up (plugs, wires, and cap)
- Fuel Filter
- I have an o2 sensor, just haven't put it in yet..

I also pulled the codes off of my ECU and I got the code for a maf sensor. I am still getting it even though I replaced it. I haven't reset the ECU or drove the car since I replaced it though..

Anyone have any other ideas?? Timing? Distributor? Maybe injector plugs??

I need to get my car back on the road ASAP!

[nissan2.4]

Sounds like ur running extremely rich especially since removing the fuse for ur fuel pump makes it run ok. Did u change the fuel injector o rings? I think fuel is bleeding past the o rings or ur fuel pressure regulator is stuck open, try doing a fuel pressure test and see if ur system holds pressure.

[Codelicious]

Its really weird. It didn't die when it was idling when I removed the fuse. But than again, it is the Fuel Pump fuse and not the Relay.. it won't start up with the fuse out, but it will idle fine. Once you give it some gas it dies instantly.

I will be checking the Fuel Pressure Regulator and if thats fine, well everyone has been saying that it could be the Head Gasket.. hope not.

[nissan2.4]

Do a compression test to find out, if compression is too low u might also have a burnt exhaust valve.