code 21 on 91 240sx.. how to fix

hey guys so i started looking into my 240.. the only code that came up is code 21 which is "Ignition signal in the primary circuit is not being entered to the ECU during cranking or tuning"...
does anyone know how to fix this... it runs and drive like crap and still runs the same when the 3rd spark plug wire is removed... i also tried unplugging the injector for that cyclinder but cant tell if its it or not...

according to the little bit of searching i did, this error code is from a problem with the ignitor/coil. good luck. I would try and swap that out. too bad you live so far away, I have one in my basement.

i agree with u... i tried putting a sparkplug into the third plug wire and am getting weak little sparts... u can barely see it and it was dark when i tested it

yeah dam to bad u live to far

^^ i read through it and it doesnt really help... i cant tell if my sparks are weak or is it the injector... i checked all the sparks and they all are sparking but seems weak... only if i had a 240 buddy near me with a ka24de

kouki_chee wrote:

^^ i read through it and it doesnt really help... i cant tell if my sparks are weak or is it the injector... i checked all the sparks and they all are sparking but seems weak... only if i had a 240 buddy near me with a ka24de

KA's are the devil....

yeah but i still love them...

i dont, i want all my coupes to have 2js..

hope you figure out your problem! im no help. i just drive.

if it runs like crap after you take out the spark plug wire than your injector is fucked, and you are going to need to replace it or the plug is shut too

thanks guys... ill look into it after work today...

ok well im gonna atempt to change the injector from 2 to 3 and see if it works... hope so... i also got it to run alittle better though... cyclinder 2 spark plug had a rubber piece from a sparkplug socket still on it... im guessing from the original owner... any help/suggestion will be greatly appreciated

well guys im at a dead end... i removed 3 of the 4 screws holding the back plate for hte 2 injectors...i started with a regular screwdriver but started stripping the head so i went to autozone and bought a impact screwdriver.... i thought it was broken for 1hr because i didnt really know how to use it until i kept trying and got it but now i stripped the last screw with the impact... how to i go removing it without buying a screw extractor... i spent all my money already...

The screw is shot . Can you clamp a channel locks type of pliers on it and get it out? Then just go to True Value or something and match up the screw and replace it. I also have a fuel rail with all 4 injectors still in it sitting here. Too bad u r so far away!

yeah i tried it and it wont clamp right without me pulling the whole rail out first... im trying not to spend money i need to save... yeah dam i wish we live closer... probably would have all this crap figured out... thanks anyways bro... i want to get it done so i can go to the meet too... dam maybe next time

Damn man, all that work and I JUST read this thread... I had the same problem with mine and pulled the same code, it turned out to be the spark plug wires. I pulled them out and inspected it, they had cracks around the boot causing the spark to get grounded on the engine before reaching the actual plugs. Or sometimes, the assembly of the wires are just shitty and the crimp just isn't tight enough or it can get loose over time. Just get brand new good ones. Don't settle for the cheapest one you can find for a temporary fix, cause you get what you pay for. Get that rubber piece out from the spark plug if you haven't already. Lol.

Sorry about the bad time its givin ya. Hope you can fix the screw problem.

well my spark plugs looks good still... they look like they are no more then 1year old... idk maybe because they might be cheap

The wires homie! Looks can be deceiving. Its not the outside that counts, its the wires underneath. Lol. No need to change the plugs if they look good, just check the gap. But the plug wires, especially if they're cheap, 1 year might be too long if you(or previous owner) pull em off and on.

true... welll anyone want to trade for some parts... i just remember i have 4 coilpacks from my qr25de engine... off a 02 se-r spec v... might be usable with sr20s