Ka24e misfiring and rough idle

[Jsicx]

Hey guys I'm having some annoying problems with my ka, it starts right up, but dies unless I hold the gas, and when I do hold the gas my car constantly misfires.

this is a 1990 singlecam by the way.
all stock

Things I have noticed:
-Misfires constantly if i hold down the gas
-really low idle
-previous spark plugs were black, oily and smelt of fuel
-white smoke shoots from the exhaust
-Oil is typical color, blackish brown,but smells of fuel
-coolant is still very green
-Good spark between all four cylinders


Things I have tried/replaced:
-Cleaned Iacv, aac
-cleaned maf, didnt work so I got a new one and still doesnt work
-new fuel filter
-new fuel pump
-new fuel injecters, with new o-rings
-distributor,distributor cap and rotor
-new ngk wires/ ngk plugs

This has been bugging me for a week in a half now, would love to hear any suggestions or input. Thanks!

[LOUD240]

mine was doing about the same thing, I replaced the 2 wire intake air temp sensor an it fixed it

[Jsicx]

Okay so today I replaced the air temp sensor and the coolant temp sensor and my car is still running horribly. I will take a video of it later on today to show what it sounds like.

I thought it could be a bad injector/ o-ring but I replaced all with new o-rings and still misfiring while on the the throttle, and idle bounces around from 0-750 rpm

[Mishkin_707]

How old is your battery/alternator? Low battery or alternator will cause it to do that, clean the battery terminals make sure you're getting good contact and there is no corrosion

[iveexcaped3]

Get an dvom and test the wires going to the maf

[Jsicx]

Previously before my broke down I replaced the alternator and battery, later on that night my car started getting weird misfiring and hesitations, and than eventually died...Turned it on started right up, but everytime i gassed it would kill itself...It eventually is like this now...240sx misfiring/bad idle - YouTube (http://www.youtube.com/watch?v=ySRIaEx2uwg&context=C4207e46ADvjVQa1PpcFN3I9lOS0BtQTKShgovi35N kwXIEmrnFGE=)

[Jsicx]

Hmm I talked to a friend and he says my car for some reason retarded it's timing so it's running super rich and dumping fuel in my oil... Any ideas on why cel would turn on and retard my timing?

By the way I'm going to check the Ecu codes and see what it comes up with

[iveexcaped3]

did you check the timing or did he just say it retarded its timing?

[Jsicx]

we havent checked the timing yet, but we are going too...

By the way my ECU used to read the following:
12 Maf
13 Coolant Temp Sensor
34 Knock sensor
45 Injector Leak

But I replaced all the injectors and Coolant temp sensor
My ECU now reads only Code 12 MAF but still is running like in the video.

any suggestions?

[iveexcaped3]

I'm telling you check the wires going to the maf like I stated before. your ground might have gotten messed up some where. It fer sure sounds like a maf issue if you gotta hold the gas just to keep it running.

[Jsicx]

I'm telling you check the wires going to the maf like I stated before. your ground might have gotten messed up some where. It fer sure sounds like a maf issue if you gotta hold the gas just to keep it running.

Okay I'll check the wires going to the MAF... along with the rest of grounding wires/sensors. I will try to see if unplugging my MAF will help my idle, because i read this will determine whether or not you MAF is good or not...

[Jsicx]

Okay so I checked the wires to the maf and they all look fine, my car idles without the maf plugged in but still misfires is that all due to a bad MAF?

[Jsicx]

I checked my wires and they all seem good... Seems like previous owner replaced all the vacuum/ grounds and maybe even the wire harness, it's all very clean...
I did the MAF test with it unplugged and my car idled fine for a little bit but died eventually and still misfired...

Please help I really wanna drive my baby =[

[iveexcaped3]

Hit up a friend and see if he can swap maf with you for a second. If you lived closer I'd come help you out. Do you have a fuel pressure tester?

[Jsicx]

I have tried that already i switched mafs with my friends 240 that runs and still the same exact thing =/. as for fuel pressure tester I do not have, but i had a talk with my friend and I forgot to mention that i installed a high performance fuel pump and maybe my FPR (fuel pressure regulator)went out. were going to test out the regulator tomorrow... Hopefully this solves the case ^.^

[tapdeznutz]

check grounds...also had the same problems you described but only at cold start up...went thru one fix at a time...basic tune up=plugs, fuel/air filter, fuel injector cleaner=did nothing...went with grounding kit=felt a bit better. check TPS setting. check timing.

i have a side question. how DO you check timing on sohc engine. i mean where do you look from, at top of shroud? i have some timing questions..

[iveexcaped3]

yes check it from the top of the shroud, clean of your pully and needle so you can see them i even run chalk ontop of the timing marks so you can see them clearly

[hippo_chips]

I'm sure you have, but did you check for air leaks after the maf? That rubber hose coming off of the throttle body was cracked on mine. Car ran exactly as you described. Never realized it was the reason until I took it off.

[Edwin562]

hows your fuel pressure. do you have a pressure gauge?

[Jsicx]

I do not have a fuel pressure guage but i can get one, If my fuel pressure is too low/too high, what am i looking for to correct.

[Jsicx]

Okay so I haven't check my fuel pressure yet, but everything fuel wise works and my friend checked my timing it's all good, but he says my car is in limp mode... We were wondering about the maf, because my car runs good without it in, how can we check the connections with a multimeter?

[S13ZX]

subcribed........im going through the same thing.....and cant figure it out.....tps and maf. sound about the most promising.....also check your vaccum lines.....and mayb try switching to a stock fuel pump. see if you see a change on idle......

[iveexcaped3]

if its too high or too low your looking at 2 things fuel pressure regulator or fuel pump. depending on where you test it at. you said you put in a high performance pump right? theres three wires on a maf sensor 12v ground and signal. your car can run with or without the maf plugged in if you stay on the throttle, it should stall out unpluged on a working engine. your fuel pump might be pushing to much pressure making your injectors leak and flooding out. how does the exhaust smell? rich lean?

[Jsicx]

FIXED i checked all the sensors with a multimeter and all of them were on point except the MAF when i turned it on, I checked the pigtail and one of the wires were simply out of the place( the middle one) but we repsliced the wire and started her up and my car RUNS ^.^still have CEL though =(

[iveexcaped3]

Dude that's what I told you to do 5 days ago lol when it comes to single cams I've run into every problem lol but good job what's the cel code

[Jsicx]

Haha my bad it looked good when i checked it, but i took the rubberboot off the pigtail of the maf and the middle wire was hanging lol.... i havent checked the CEL code yet but my friend says theres a way we can clear the CEL light

[iveexcaped3]

Yeah, take the neg terminal off the battery for 2 minutes.

[240SXREX]

i had the same thing and all at one time. the acc valve was clocked,aicv valve to and pulled the air intake piping that is in front of the throttle body was cracked which the eom piping is known for. This makes the second one that i had to replace. I'm replacing it with a injen or k&n. Thanks for this post. Peace

[240SXREX]

also it threw a 13 and 41 code on the self diagnostic mode. Maf, air intake temp sensor couldn't get an accurate ready due to gapping hole in air intake piping.

[240SXREX]

look under the bottom of piping. I'm done.