Two cylinders not firing, rough idle, low power..blah blah blah 1990 240sx Ka24e

[meshmasteryow]

Ok, so my car has the same problem as everyone else's but none of their solutions have worked on my car. It is idling really rough (like the motor is trying to do a cartwheel) and has a gigantic loss of power. Cylinders 3 and 4 are not firing properly for some reason.

Things I have tried:

1. New ecu2. New fuel filter3. New pump and strainer4. New MAF sensor5. New fuel rail and fuel pressure regulator6. Swapped injectors but the problem stayed on 3 and 47. Removed IAA valve and cleaned (THOROUGHLY)8. Checked ecu code and got 55 (a.k.a. no problem)9. Checked timing (in time)10. Replaced Distributor (entire unit) 11. Tugged on all of the grounds I could find to no avail 12. Checked compression (179-181 on all)

I am totally stumped. I love my car and I don't want to get rid of it but I CAN NOT figure out what the frickin hell is going on.

[meshmasteryow]

Also, sorry I'm a noob. I suppose this should have gone into the Nissan online mechanic area. If a moderator would do me the honor of moving it I would appreciate it very much. Thanks.

[bone_stock_240]

I don't see new plugs or wires on that list. 2 of my cylinders weren't firing, and I replaced the plugs and all was well after that.

[meshmasteryow]

The plugs and wires are a couple of months old. I checked the plugs and they looked fine and were still gapped properly. I just assumed they were sparking because the plugs were dry right after I ran it for a minute and pulled them out. Since it has full compression I'm guessing there would have been a little fuel in the cylinder and on the plug if it didn't fire right? It would really suck if it was my damn wires this whole time.

[bone_stock_240]

yah, that would suck after going through all that effort changing all that other stuff. Look on the bright side though, at least most ofyour fuel system is now new and won't give you as much trouble. The same thing happened to me after I swapped my clutch. We were beating ourselves over the head trying to figure out what we did that would cause the engine to idle really really rough, have no power, and run really rich. I spent ages going through the vacuum lines and was completely stumped. I even started to pull the transmission again, even though I couldn't see the connection, that was the only thing that we messed with. The person that I was working with decided to pull a couple of the plugs to see if that was causing the problem. He pulled 1 and then 4 and nothing happened so he concluded that that wasn't the problem. So then I pulled 2 just for the hell of it, and the engine shuddered like hell and almost died. Same thing with 3. It was pretty funny how the 2 plugs he pulled were for the 2 cylinders that weren't already firing.

[DjPantsSpecR]

honestly, you might just have two plug wires switched around, it happens all the time.

[meshmasteryow]

It started it in the middle or driving though. Wouldn't have been messed up the whole time if I crossed them?

[DjPantsSpecR]

oh oh most definately, sorry man, if you wrote that i jsut missed it.

its jsut a common build problem, i've done it a few times, so i always look there first when it fires on two.

check the resistance across all the injectors, and lemme know whats next.

[meshmasteryow]

The injectors are all getting 14 volts and the resistance is around 13 ohms on all of them.

[meshmasteryow]

Oh well guys, I'm buying a dual cam swap this Friday for a skimpy $300. I got uber lucky with this deal. It's a strong motor too! I rode in it (the car) yesterday!