Hey guys how’s it goin? I have a 1993 240sx hatch with a stock KA24DE. So the other night my car started to act up at idle (bogging down and almost dieing). But after a few revs it would be okay for awhile. I assumed it was because of the system I installed recently drawing too much power or something. So the next morning I tried to start the car and it DID NOT want to start. Which is weird because I’ve had 0 problems. After it finally started it sounded like it was running on less than 4 cylinders, and when it idles the engine and car shake like a banshee!. So I tried removing the plug wires one by one as the car idled and discovered that if I left #1 and #3 unplugged, it did not affect the way the far runs. Plugged in or out the idle and Performance are completely the same. So I’m in a complete pickle here. This is what I’ve tried so far;
-New spark plugs
-New Distributor cap and rotor
fuel injector cleaner
Does anyone have any helpful insights or suggestions? Thanks alot.
Try unplugging the injectors one by one, if removing the plug from an injector does not affect the idle, the cylinder is not firing. This could either mean no compression, no spark, or no fuel.
If you are unsure of whether you are getting spark, try grounding the spark plug to the valve cover or something conductive. Try not to shock yourself. lol
You can also try to check the resistance across the injector coils. Use a multimeter, the readings should all be around 12 ohm’s for the red KA24DE injectors. If it is significantly higher like 30 ohms, your injector is fucked.
Okay ill give unPlugging the injectors a shot. But if unplugging the spark plug wires does nothing on cylinders 1 and 3, wouldn’t unplugging those injectors do nothing as well? managed to shock myself with the wire but found out they all have spark lol. I’m gonna go pick up a multimeter from a buddy in a few mins. Thanks alot guys.
Okay so I pulled the injector wires and it yielded the same results as the plugs. I can have 1&3 unplugged and nothing changes, but if I unplug injector 2 or 4 the car dies out. Working on getting the meter and a compression tester.
Okay so i got the mulimeter and a noid light. I tested the resistance across all the injectors and they all checked in between 11-11.5 ohms. Then i tested to see if they where getting power from the clips with the noid light by cranking it over with the wires in the clip. It illuminated after cranking it for the first one, then all the other clips had constant power whether the key was in or out. So i think its safe to eliminate the injectors as the cause? Im working on getting a compression tester now. If the compression test checks out then im gonna get some new wires. I know the plugs have spark, but i dont know its the proper amount? Im hoping compression is good because i dont wanna get into that much money right now lol.
Edit: Also used the multimeter to test how much juice the clips had and it was around 8-9 volts? dont know if that is worth anything.
Edit: Did the screwdriver clicking test. All injectors clicked consistantly.
swap out injectors with the known working ones and see if the dead cylinder change to the others. you might need vice grips to loosen the screws as they are usually pretty tight.
For two injectors or plugs or w/e to go dead at the same time…i doubt they are the issue.
Sounds like the ECU injector driver, Try a friends ECU or some one who wants to sell one that will let you try it out before hand. It will be easier and cheaper to replace your ECU rather than getting it repaired.
To my understanding(dont mark my words) there’s 2 separate injector drivers in your ecu, one controls 1/3 and the other 2/4. Since the drivers are separate from each other and one fails you can loose 2 cylinders which suits your symptoms.
What happens if you drive the car and just put your foot to the floor and try and do a great big burnout up the street? Sounds dumb I know, but I had the EXACT same problem and I thought I blew my engine, car idled like it was on 3cyl, shook the whole car, drove like a POS on 3cyl. I was ready to scrap the car didnt even care to try and fix it, then I tried to do one last big ass burnout up a hill and then all the sudden shit started KILLIN IT smokin second gear up the whole hill. From that point in time the car drove fine aslong as I would rip it but if I drove slow like grandma it would go back on 3cyl mode lol. I never did actually fix the problem as it was just a $400 beater but my guess was always a shitty fuel filter. Just do a big burnout, if it fix’s the car then change your fuel filter. Trust me. lol
Hey guys so i bought new plug wires and that didnt fix the problem.
Im not too sure, I havent removed the injectors yet, ive only ohm tested them and made sure they where getting power. Removing them today.
Replaced distributor cap and rotor already.
Doing that today. Thanks
That is very useful information. Thanks man. Im going to definitely try that ASAP! you da man! haha. Could resetting the ECU fix the problem potentially?
Lmao thats awesome. Thats the easiest and funnest test, ill give it a try but i have a feeling its something a little more serious than that :P. Thanks mang.
Hey DoZeDrift I tried what you said and no results lol. No way in hell this puppy is doing any kind of burnout. Barely even on snow!! I think DirrtyDevo is right.
Re-checked all electrical connections to everything and sniffed around really good while it was running and didn’t smell any fuel at all.