starts sometimes but wont idle, wtf?????

[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.

[OutToWinPAHC]

I would try cleaning the throttle body, IAC valve, and even pull the injectors and see if they are dirty, then soak the bottom / top (not the electrical area) in seafoam and replace the O-Rings.

Then I would check all sensor connections and clean them, and check the vacuum diagrams again and make sure they are right.

How is the o2 sensor? And have you checked for engine codes?

And to bust a little balls.... how come you didn't take the oil pan off the other engine and swap them?

[240sx92bnb]

first off thanks for your response I truly appreciate it. I will try cleaning the throttle, IAC valve and the injectors as well. To my knowledge the O2 sensor is good, no check engine light at all. As for the codes ill have to get the link again my friend sent it to me but in that week and half of work it got auto deleted from my txt messages. As for the harness I'm actually thinking of just swapping out the harness for my original one from the hatch. Ill have to check my book for the vac diagram again. The problem though is that I have the Chilton book that covers my car, the 200sx and the Altima so things can get confusing esp since there are no pics just drawings. Does any know of a detailed book that covers our cars?O and thanks for the ball buster added a little humor to a humorless situation. I never changed the oil pan because since that kid blew a hole in his engine, rod right through the side of the block ill post a pic one day, and it seems to be some side signs of nos used my friend said. I just decide to use as little from his actual motor as possible. Plus as i said before there was no leaking or any signs of any kind of hole. Ill change it if it'll help though but i doubt it.

But the question is why would a motor that was running and running hard all of a sudden not run at all once it was swapped? As I said I have spark, fuel and air i think there is sensors somewhere that is stopping it from idling. Just dont know which one it could be.

[blacksrjdm]

The dent in the pan may be restricting oil flow to the pickup. I would change the pan, just clean it well and check it for leaks. The rod went through the block, but not through the pan right?

[240sx92bnb]

ya it was just the block on the 91 KA. the pan wasn't effected on the 91 KA motor. But once again to my knowledge this wouldn't stop it from starting and running it would just create aloud a** series ticking, right?

[240sx92bnb]

of ticking^^^^

[im_looking_for_a_240sx]

ticking...is it injector tick or....ticking like sound that may be restricted oil flow to block, leading to lots less lurication on the internals/bearings, causeing them to wear down, and cause rod knock? (i'm not sure if rod knock can develop that quickly....)but hopefully its not that....

[blacksrjdm]

I dunno, if the engine isnt getting oil pressure will that cause it not to stay running?

[OutToWinPAHC]

Is the factory idiot light at least off, and the oem gauge showing pressure?

[240sx92bnb]

i did some more research and i found out that when you remove the dizzy it throw off the timing and u have to set it TDC, is this true? I'll have to double check the gauges again now that u mention it but i don't recall seeing anything that would indicate any kind of problem.