Replaced fuel injector, 1st cylinder not firing.

[AeonTorpor]

Okay, I just bought a 1991 240SX SE 5-Speed Hatch last week and knew the #1 fuel injector was bad. The resistance was too high, reading 23 ohms when driven at higher than 4000 rpm.

Anyway, it was running fine then i forgot about the 4000 rpm, went over it, and the engine began performing erradically from idle - 2000 rpm.

So I replaced the injector and it ran perfect for about 48 hours, then the 1st cylinder stopped firing. It's very hard to turn on, and then the idle is 100 rpm too low. It will run, but only on 3 cylinders til' around 1800 rpm (you can feel the 4th cylinder kick in) then it runs smooth.

There are no leaks, i've checked. All injectors measuring about 10-6 ohms resistance. I just replaced the spark plugs and spark plug wires. I know its the first cylinder cause i disconnect the 1st spark plug wire, and it doesn't miss a (crappy sounding) beat, i tried that with the other 3 cylinders, and it stalls immediately. Battery is good, no water or fuel in the oil, and no oil or fuel in the coolant. There is a very strong smell of unburned gas, so i'm thinking that the injector is firing. But I am just getting into cars so...

Any help would be appreciated.

[Ni2s4s0aSnX]

Probably another bad injector. Or a bad plug. That is if your thinking that it isn't somethig worse.

[AeonTorpor]

I don't see how it would be another injector or plug causing the first cylinder to not fire. On top of that, i've tested the other cylinders and they are all fine.

And i hope it's nothing more major than the distributor, because i don't have anymore money to keep replacing stuff for the moment being.

Damn college books and payments.

[DAEDALUS]

Maybe not the plug itself, but perhaps not firing. Bad distributor? Pull the wire off the #1 plug and attach it to a spare plug, then ground it to the car to see if it's sparking.

[Ni2s4s0aSnX]

Well, the spark plugs are what make each cylinder fire. But I'm just throwing out possibilities, if you're going to question peoples advice, people aren't going to want to answer your questions. But back on the subject, it could also be a bad plug wire, or the whole distributer.

[AeonTorpor]

Well sir... if you had read my post there might have been the assumption that i had already checked the spark plugs... and perhaps replaced them. Not that it says it or anything (hint)... And the lord knows, that injector #3 is what injects gas into the 1st cylinder. I asked for help, not mr. obvious. Nevermind, i guess i'm better off going to a mechanic. For those that actually wanted to help, thank you, in particular Daedalus.

[phuphyter]

where did you get the injector from? if you got it from autozone or any similar store, it might be the o-rings. the replacement o-rings that i bought from them are totally different from oem. try replacing the o-rings with ones from the nissan dealer.

[AeonTorpor]

Yeah, I got the injector from Autozone, Thanks. Oh by the way, since i'm gonna try replacing the o-rings, do you know a good way to get the injector out of the rail w/ out damaging the injector? I nearly had to rip the last injector to shreds to get it out of there.

[AeonTorpor]

Well, here's some interesting info. I was talking to my mechanic friend and he asked all the norms, spark plugs, wires, distro, runs?. And he hears it and feels the shaking and such. He says that most likley the head gasket is blown. Since the other cylinders are firing and its getting gas and spark to the 1st cylinder, the only thing that makes sense is at higher rpm the cylinder leak doesn't have enough time to decompress the cylinder, so at higher rpm's it runs okay. So I am thinking, that's impressive... and wow, that really sucks. So i guess i'm gonna have to save up some money here for the tear down. Well, on the bright side, the car still runs for the moment being.

[phuphyter]

Yeah the faulty injector that I had to replace was a pain to get out. We ended up screwing in a drywall screw to yank it out because we wore down the pastic in an effort to remove it. Since you just installed the replacement, it shouldn't be too hard to remove. Just throw an old tshirt or rag on it as a buffer so you don't scratch it and use some channel-lock pliers. Twist and pull. Should come out pretty easily.

I'd get a second opinion on that blown head gasket. How many miles does the odometer show?

post a pic of the injector if you can. then maybe i can tell you if you need the oem o-rings. i never used the one that i bought from autozone because it turned out that 90's q45 shares the same injector as the ka's. my uncle had four laying around the shop. we test fitted those and they worked. the only problem was the o-rings, specifically the lower one.

[AeonTorpor]

okay, i checked the injector, it was a ton easier than before as you said, and everything was okay, replaced rings/ didn't seem to solve the prob. Oh, and it has 138k mi. on it. I don't have a camera so no pics yet.

Anyway, i got a second opinion on the head gasket from a family friend. He said that since there is no smoke whatsoever, no cross contamination of fluids, that the head gaskets are okay. He said that either there is a lobe on the cam that is worn down, which he said is very unlikely. Or there is a valve of somesort that is malfunctioning in the EGR system, since there are 4 individual valves to each cylinder, the #1 cylinder valve could be clogged or damaged, causing problems to only that cylinder.

I can't check that out till i get my other car running, because i'd have to tear off the fuel rail and the upper air intake plenum to get to the valves.

[FliMSiCaL]

do a compression check on ur motor, if number 1 shows lower, thats why its not firing. If it does show low, drop some oil down the spark plug hole and see if it fires up for a few minutes. If it does, you have bad rings in that cylinder. If not, check ur timing and valves.

[AeonTorpor]

Alright, I read through what everyone wrote in this topic and i came to the conclusion that i sound kinda frustrated (an ***). Besides my keen observations, I got the Check engine light the other day, so i checked the ECU, it gave code 45, I took the injector out and it had a blown o-ring. Odd because it was fine last time.

I replaced the ring again, and then it wouldn't even fire the 1st cylinder at higher speeds. I thought it must be the injector, so I took the 1st cylinder injector back/ exchanged for another. I turned the vehicle over, it started up w/ no problem, first try, it took only 1 sec. It was idling at around 750RPM, nice and smooth, I was so happy. But...

I take the car around the block and right as i'm coming back it starts to smoke, i park, blue smoke. I turn off the vehicle, wait a few, check the oil, it's fine, no gas, coolant, appropriate level. So i turn the car back on, and it starts like crap (sputtering, uneven idle, hard to start again). So i left it over night, I come back in the morning, try it again, same thing. I remove the injector again, the o-ring is fine, reinstall it.

I then try to turn it over again, and the starter just clicks once, that's it. My huge *** mistake.... cause i was tired of taking the rail off, this time i forgot to properly empty the fuel rail, causing fuel to flood the cylinder. I guess you call that hydrolocked or something, i think that's a good name... anyway.

We pumped the gas out through the spark plug hole and try to fire it up again. it's cranking like crazy, but it's not starting, it's like it's just about to start, then nothing. The spark plugs are fouled up beyond belief.

I take a compression test... 60psi on all. I stop for a second, and think, how the hell did i lose compression on 2,3 and 4, they were fine. I check the oil, Non-existant. None. WTF? the dipstick smells like gas. and that's where i'm at... I noticed a puddle of gas below the car, but thought nothing of it cuz i was emptying the rail like 4 times, and draining the line and such.

Long post i know but i know i like detail and i'm seriously stuck... and quite honestly, scared that it's not fixable ($>used engine). I'd greatly appriciate some feedback. Please tell me if i did something wrong, but gently, i'll hate myself for quite a while.

[AeonTorpor]

Okay, summary time.

Problem: Rough idle, First cylinder not firing until 2000RPM.

Solution: Fuel Injector O-ring damaged - replace

Problem: First cylinder not firing at all.

Solution: Faulty Fuel Injector - replace

Problem: Not cranking.

Solution: Flooded cylinders caused by improper emptying of fuel lines. - Empty

Problem: Cranking but not turning over.

Solution: Washed piston rings due to gas. - Transmission fluid in cylinder to re-seat rings.

*Sigh* it costed $165... A lesson well learned.This is FYI, cause I now know, so no one else has to pay it.