starts at times but wont hold an idle

[240sx92bnb]

Ok I took my KA24DE out of my 92 hatchback and swapped it into a 91 coupe. The original KA24DE that was in the 91 coupe was blown. When pulling out the KA from the 92 hatch it fell about two feet (fail) and put a small dent in the oil pan, there is no leak or anything from the oil pan or anywhere else. I know what your thinking that is your problem right there but as far as i know there are no sensors or anything else besides the pump in there.

Once the swap was completed and we tired to start the car it would not start, we tired; changing the dizzy, sub coil and ECU. It remained like this for a week until we realized that the fuel lines were backwards and it started, second failure.

So then i get stuck at work for bout a week straight so I didn't have time to play with mt baby until yesterday. O i should mention that the coupe was sitting for awhile a couple of months before i got it and the gas went bad. It was like a brown color( think it turn to turpentine). So yesterday we pumped out the whole 1/2 g of bad gas. Put about a gallon and half of fresh gas in there with 108 octane buster. So it started up yesterday when we tapped the gas and turned the key. The car would rev up from us tapping the gas but if you let off the gas or floor it the car shuts off without holding an idle. Switched the original ECU from the coupe back thinking maybe they are mapped different. No luck.

Tired tonight and couldn't get it to start at all figured hey put the ECU from the hatchback back in there again, still nothing.

Please any ideas or suggestions or related personal experience would be helpful.

Things I've tired and checked; changed ECU's more than once, lol, changed dizzy twice, the one from the hatch is there now, change the sub coil to the one from the hatch, checked the harness over and over for something unplugged, the only problem we partly saw were that two vac holes between the valve cover and the fire wall were broken so we fixed it also the sensor nearest the driver side was broken on the bottom where the vac holes connects this was also changed. All other vac holes as far as we can see were connected except the EGR valve, cant figure out where the connection is. O also changed the headers w/ the bridge that goes to the intake manifold. My MAF is good and it clean.

So basically please any help would be appreciated i know i have fuel, spark and air cause like i said i got it to start a couple of times but it would hold an idle.