studder/misfire?

when i first start my car in the morning, i dont wanna say it misfires, but it studders a lot, and then once warmed up it drives normal until it gets around 2700-3000 rpm and i feel the studder again, and after 4000 its fine. and at any time if i floor it my car just sounds like shit and doesnt go anywhere for a second, and then it catches and goes. checked all ignition parts (plugs, wires, rotor, cap) all good, checked injectors, clean, new z32 fuel filter.... now i heard if motor mounts are bad (mine are bad) you lose torque, but i dont know if that could cause the problem... if anyone has any suggestions lemme know, thanks.

check your timing, maybe even your injectors


Clean your maf with this, see if that helps

z32 fuel filter with stock MAF n shit???????

Rad Mike wrote:z32 fuel filter with stock MAF n shit???????

why not?

IDK!?!!!?!!

i tried messing with the timing before, and it ran really good if it was all the way advanced, but the studder issue lasted a lot longer when i would first start up the car. i am going to try cleaning the maf sensor tho, thanks

i tried messing with the timing before, and it ran really good if it was all the way advanced, but the studder issue lasted a lot longer when i would first start up the car. i am going to try cleaning the maf sensor tho, thanks

sounds what started happening on my red hatch.. turned out to be head gasket

haha, i was accidentally signed on my friends name, and ithats weird... but i do smell somethin sweet in my car every once in a while.... well ill be changin that out during winter

Head gasket- do a compression test to be sure
Injectors- have the car idle, pull each injector (one at a time0 to see if engine speed changes
Motor mounts should not cause what you say is happening. They'll cause a clunk sound. Have your car idleing, walk to the front with the hood open and rev it up, if the motor torques excessively motor mounts are going or shot.

yeah my mounts are going for sure, but ill do a compression test to see whats goin on and ill also try that injector test, if engine speed changes im guessing that injector is bad?

If when you pull an injector and it doesn't change the engine speed. Then you ohm out that injector to see if the problem is electrical or if its just the seal. Proper ohm should be about 11-12 if i'm not mistaken..

it could be as stupid as a Bad/loose/missing GROUND

Revgasm_Josh wrote:it could be as stupid as a Bad/loose/missing GROUND

True..My RB ran like dog shit, I added 3 more Grounds (Exhaust, Intake, one at the turbo) now it runs Smooth all the time..

well untill i boost past 6lbs

i cleaned up some of the grounds on the ka a while ago, but theres a few more i still have to get, im pullin my motor after the event on the 18th and hopefully i figure out whats wrong with it, thanks

I've got a similar issue.

I've been told IACV.

I cleaned the IACV and EGR... nothin. I'm leaning toward leaky injector o rings now.

Try adding another ground to the exhaust somewhere. or to the intake or something. I added 3 or so grounds and helped ALLOT. still studders under boost but that will be fixed shortly

Im gonna resurrect this thread cause my car has recently started to have a similar problem, its a bone stock ka24e besides headers and exhaust. My engine pulled hard and ran great until 2 weeks ago. It started to idle kind of rough, but not too badly. Over this week it has started to idle much worse and i have shit for power from 1500rpms to about 3800rpms, the car studders and bogs in this rpm range and it feels like its running on 2 cylinders. When it gets to around 4k it goes smooth but still seems slightly low on power but barely noticable. Another thing when im in the shit rpm range, ill be on the gas slightly, like regular dd level accel, and then ill floor it, no difference, the rpms rev at the same slow pace.
Ive cleaned my maf, did nothing. I didnt see any obvious vacuum leaks, same with the injectors. I havent checked the potential electrical stuff mentioned in this thread but would a bad ground really make my car run this bad? Like in that rpm range i can barely accelerate, and its getting worse every time i drive. It has ngk plugs and ngk wires that are pretty new aswell. Seeing as i dont have too much hands on experience with older cars, im hoping its some easy thing im overlooking haha. Any suggestions?

test your maf

or just try someone elses on your car. It sounds like you have a defective maf and cleaning it usually helps but if its defective you gotta replace it, cant just clean it.

not sure how to test them though but i know there is a way.

mine idles fine, drives fine, but once I try making a pull it does the studder crap you guys are talking about.

jdm since u got an SR its prob a misfire or a boost leak

yikes

jdmj914 wrote:yikes

Just check for boost leaks and check your spark plugs see if there is any signs of misfiring or running lean/rich