need engine help with ka 240

Stevomr2Turbo · #1 05-03-2005, 12:07 PM

i was driving my car home today, when all the sudden, it started sounded reallky funny and has very little power.. it sounds like its running on 3 cyclinders... or like a subie or something odd.. its not smoking . it'lll start up just fine and idle pretty welll, but when u try to rev it a lil.. just sounds like really nasty, and the exhaust sounds like a train chugging, lol... there isn't any check engine light on...s o i dunno, could it b a spark plug, injector.. or something . o, and btw, i just replaced the plugs not even a week ago... thanks,steve

nissanfanatic · #2 05-03-2005, 03:44 PM

With the car off, unplug the MAFS. IF the car starts up and runs fine in CLOSED LOOP "no hard acceleration. Just normal driving.", then it is the MAFS. Did you gap the plugs properly? Check out the coil too.

Stevomr2Turbo · #3 05-03-2005, 04:18 PM

i haven't tried to start the car with the mafs off yet.. but the plugs that i got are like denso i think. they were pregapped, and have been running fine. so once i find my spark plug wrench, i'm gonna check em out. also, i'im unfamiliar witht he coil.. what ami looking for...? thanks

nissanfanatic · #4 05-03-2005, 08:03 PM

resistance across the polls. OR.....

Just pull a plug and allow it to sit with the threaded part touching the valvecover. The threads must ground to something or the test is useless. Try starting the car and watch for spark. Prolly better to try this at night so you can see it well.

Stevomr2Turbo · #5 05-05-2005, 01:19 PM

ok.. well, i haven't tried the spark test, but i'm gonna do that later today. i started the car and turned it off.. then checked the plugs and it seemed like only the first plug was wet, all the rest appeared to b dry wheni pulled them out... the previous owner had to replace one of the injectors... could it b that? I REALLy need my car to b back up and running. thanks, steve

nissanfanatic · #6 05-05-2005, 09:42 PM

Check the injector O rings. I bet he didn't lube them up and it made a very slight cut. I installed one wrong and about a month later, it just tore itself apart. But first, while the engine is running, pull the injector clip off of that cylinder's injector. If the engine sounds better with it off, then you can rest assured that it is an O-ring. Or pull the plug wire. If not, then your search isn't over.

http://1stnissanparts.com/oe_parts_cat.html

Thats where I bought my o rings. Freaking advanced auto parts sold me only the top O ring and said "This is our O ring kit," Yea, right, theres only one o ring..... JUst make sure you get two in the box or whatever per injector.

Chuki_breath · #7 05-05-2005, 10:22 PM

does your car shake like it has a v8 in it??? If so its definantly an injector. But im sure you would of said that if it was shaking, so i dont think its a bad injector altogether.

Do what fanat said, its prolly some little stupid malfunction.

zdude · #8 05-06-2005, 10:10 AM

well if the one plug was wet, maybe it wasnt sparking at all. did you replace the plug wires at the same time? distributor and rotor? all cheap and easy stuff...should be done anyway

Stevomr2Turbo · #9 05-06-2005, 12:15 PM

hey, thanks all for the replies... that injector o-ring idea seems logical, could that b why the one plug was still wet... there all firing great, i did the spark test, all fired good. And yah, the engine IS shaking alot, sorry i forgot to mention that, it starts pretty good, the engine just shakes really bad.. i may not have time today to check it, but tomorrow i will for sure. ehh, i might as well check it right know... the oring thing, i'llg et back to ya... thanks

Stevomr2Turbo · #10 05-06-2005, 12:36 PM

mkay. so i tried the injector clip idea.. and i pulled them off one at a time, removed, they all made the car wanan die, except the first one closest to the front of the car. When i removed that one, the car still ran fine, as if nothign happend... Same thing happend when i tried all the spark plug wires.. i rmoved the caps one at a time, and the car would stumble.. i removed the first one, and the car would still run fine, no difference in idle... soooo. i guess it ssomethign with that first injector i guess... sorry i'm a newb to stuff like this, thanks for all ur'e help, i'm slowly gettin there, at least its narrowed down a bit, thanks, steve

nissanfanatic · #11 05-06-2005, 10:55 PM

Then you should replace that injector's O rings. Good luck.

Stevomr2Turbo · #12 05-07-2005, 11:59 AM

mkay thanks, i'll order the o-rings asap.. And if someone doesn't mind. can u explain like whast happening. i don't understand it. thanks

nissanfanatic · #13 05-07-2005, 04:34 PM

The O rings seal the injector to the fuel rail. It keeps fuel from coming out of the fuel rail. IF one of the O rings busts or has a cut, fuel just bypasses the injector and dumps straight into the combustion chamber. So that cylinder runs really really rich. Not good because all that fuel can wash oil off of the cylinder walls and create a lot of friction between the piston and cylinder wall. AKA wears out that cylinder really quick. There is 34psi of fuel pressure at idle and 43psi of fuel pressure at WOT. Even the smallest cut in that O ring and fuel is gonna leak out.

Stevomr2Turbo · #14 05-08-2005, 12:18 PM

ok, i pulled the fuel rail off, and took that injector out.. the o-ring appeared to b fine. i was thinkin, if that o-ring was bad, and fuel came out between the injector and the fuel rail, wouldn't i b able to see the fuel or some wetness under that injector? and also, someone said there was 2 o-rings... i only saw one, and then like a rubber boot thing above it. thanks

Gir16a6 · #15 05-08-2005, 01:10 PM

is it a knocking sound that gets worse if you rev the engine?

POST REPLY TO THIS THREAD