KA24 Problems...

[monane]

I blew the engine in my 95 240sx and the salvage yard gave me a 91 KA24 engine. So after changing the intake and dropping the engine, the car ran decent for about 100 miles. Now after the car warms up the rpm's jump randomly and the car will die at idle. Acceleration is horrible once it starts acting up. But once the car cools down for a couple of hours the car will run like new for another 15 minutes. The check engine light is on and it said Crank sensor, Knock sensor, EGR valve, and O2 sensor circuit. Does anyone know where I should begin fixing this vehicle?

[locoluna825]

you should have never stuck that ka24e engine in it, most of the sensors are different and i doubt you hooked every last connection into that engine that came off your DE engine, the computers are also different. i can even fathom how you did that but your in for an adventure. you should have just rebuilt your DE.

first thing i would do dude is clear the codes on the computer im sure you know how since you can do an engine swap. if you don't unhook your battery cable for an entire 24 hours. after that plug it back in it should run fine again for another 100 miles, if it does you need to either put your old engine back, or put the original ka24e intake back on and (and anything else you swapped) the ka24e computer it needs it to operate correctly, and if yoru going to do that your also going to have to get the wiring harness that came off the ka24e. nobody has any luck using the ka24e block and putting DE components on it. you should have jsut rebuilt your old motor. or at least find another DE to put back in it.

[monane]

We stripped the 91 motor to just the long block and used all the electrical parts from the 95 engine on the new motor. The long block is technically the same exact thing you can read all the specs in the owners manuals for both models. The only sensor we forgot to change out from the 91 block was the knock sensor... Does anyone know if there is a compatability issue between the 91 and the 95 knock sensor?

[Jaino40]

Do as he said. Clear the codes and check again. What do you mean are they compatible? I was actually checking knock sensors today... I know DE and sr's are the same, but dont remember reading anything about the single cam being the same. If you DONT have it hooked up at all, then that can be your problem and your car may be in limp/fail safe mode.But dont quote me on that..

[monane]

The long blocks in both engines are identical. they are both KA24DE. We changed the intake and most of the eletrical so the 91 block could hook up to my 95 ECU. So in theory I have a 95 Engine in my car and the computer is giving me problems because something is messed up somewhere. The only sensor I forgot to change was the knock sensor. That is why I asked if the 91 and 95 knock sensors are identical.

[del82]

What's "most" of the electrical? Which parts didn't you change?

[monane]

The knock sensor and the oil pressure sensor... Everything else is from the 95.

[locoluna825]

you got to hook those up especially the oil pressure sensor and the knock sensors are not different as long as the 91 its on is from a dual overhead cam and not a single over head cam

Modified by locoluna825 at 2:38 PM 4/18/2009
Modified by locoluna825 at 2:38 PM 4/18/2009

[monane]

Both of those sensors are hooked up... Today as I was driving to work my car suddenly died. The car refused to start. I popped the hood and unplugged the MAF then tried to start it. It started fine without the MAF. However, It would not rev past 2,000 with it unplugged. I was able to get to work in low rpms and worked for several hours. After the engine cooled off I plugged the MAF back in and drove it back home. The car ran strong for about ten minutes and began acting up again, as expected.

[del82]

Sounds strangely like a problem I had with a Sentra long before I knew anything about cars. In hindsight, I'd have guessed it was the ECU, but then that's just a guess, and it's not like I can go back now to have a look, that car has been in the scrapyard for about 7 years now, heh. I was getting fuel cutoff at a certain RPM (no tach in that one) or if I gave it too much pedal. Took it to a shop once and they gave it back to me same day, said they wouldn't touch it, heh. Cheers for skilled mechanics in this area.

[monane]

I dropped the car off to a local mechanic shop yesterday. Hopefully they can diagnose the problem. If they do, I'll post what all they had to fix...