KA24DE Rough idle crappy gas mileage

[Toomuch240]

Car had a bad fuel injector on 4th cylinder. flooded the whole engine
we flushed it all and replaced injector car started up but shook like hell lubed up the 4th cylinder(had no compression) got good compression but car still idles rough. did a whole tuneup still idles rough. got to keep it in N or P for it to stay alive if i drive without warming up.
Drives like a champ just idles shitty below 2/xrpm and i have poor gas mileage
any help would be much appreciated

[FRoSt415]

when u lube up the pistons ur supposed to get higher compression then when they are dry. But back to your question, check the car for leaks like vacuum lines etc. if that doesnt work out look for leaks else where by getting some carb cleaner and spraying it over the intake manifold and around the injectors, see for any bubbles. Sounds like a vacuum problem. Clean ur air box? maf might be contaminated also clean it and get abck to us.

[Toomuch240]

Yeah i cleaned MAF i'll check vacum lines tom, thanks bro

[[w]hite[r]abbit[x]]

Bad front o2 sensor maybe. Sometimes the front o2 sensor can make you lose performance.

[Toomuch240]

I changed o2 and coolant sensor
engine still shakes rough under 2xrpm

[Toomuch240]

Its going to have to be an injector problem, i travel less then 5miles a day to school and work and im on E, after putting 20$, i checked vac lines all fine

[SidewaysNJ]

Its got to be either fuel or spark. i want to say fuel since you had that problem injector.
While the car is idling pull one of the injector plugs off, if the car starts shaking even more then that injector is working properly, BUT if the car runs the same unplugged as it did plugged then that injector is the problem. You have to check each injector one by one, don't unplugg them all at the same time.
If you checked all the injectors and don't find anything, start pulling you spark plugs one by one and look for the same thing. If the motor starts shaking even more then that spark plug is fine but if the motor doesn't start shaking even more then you found your problem.
Let us know how that turns out.



BTW, i just had the same problem. Don't mean to thread jack
My idle was horrible and the previous owner said he had a problem with the injector o-rings. The car was fine at first but over the course of a year I had to change the o-rings on 1 or 2 of the injectors twice! When the car ran it ran well. Well recently the car started to shake again and I’ve been meaning to send my injectors out to get cleaned and flow tested. I sent mine to witchhunter performace. (its about $18 an injector but they send you a before and after flow sheet as well as your old parts [o-rings/pintle caps]) Turned out one of the injectors was bad, it must have been stuck open. So I got 4 fresh injectors and dropped them in. Car wouldn’t crank, I’m like wtf?? Noticed a wire to the starter was loose but that didn’t solve it. Finally got the car to crank by rocking it back and forth but it wouldn’t start at all. I check the spark plugs, cleaned them and nothing. Put some brand new spark plugs in and still nothing. Just wasn’t making sense. I decided to check the oil, the second I pulled out the oil dip stick oil started gushing out the dip stick hole like a water fall. I was like wtf? Strong smell of gas. I was like no way. My oil was straight gas, the KA takes about 1 gallon of oil, I drained 2.75 gallons of oil/gas. I couldn’t believe it. And I changed the oil just under 1000 miles ago. I thought my motor was done, it has 184k on it. All that gas cleaned out any carbon build up in that block. I put fresh oil in 10w-30 and the car wouldn’t stop smoking. If you think sea foam is bad you wouldn’t believe what this car was doing at around 2000rmp. I was about to give up after about 5 hours of work. The car is actually running and stopped smoking. Oh yea and it doesn’t shake anymore. All because of a bad injector.

[Toomuch240]

pretty sure its a injector problem because when i got the car i towed it to a shop and we troublshooted all day and when we found out it was a bad injector lucky us there was 2 injectors in the back seat, pretty sure thats my hint

[Toomuch240]

so i got a fuel rail with injectors, i got good gas mileage now:D but still idles rough
gonna do an oil change and add some "restore" to it hopefully that'll fix my problem if its a compression problem.
only shakes under 1xrpm

[Ceepo]

check your cap and rotor, sometimes rust or corrosion can cause it to run like turd, i know when i cleaned mine off it made a world of diffrence... hope that helps...

[supreme_1]

check your compression on that 4th cylinder again.

your rings might be bad or gone. when you put a cap full of oil in there its going to bump up your compression. thats a good way to check if your rings are bad. so once that oil burns off your compression might go back to the crapper.

[Toomuch240]

i put new cap and rotor. What i cant seem to figure out is, it turns off when its not warmed up if its in any gear but P or N it'll just stall out. I need to figure this out before i do tranny swap :<

[Addicted2Kouki]

Check compression and check for vacuum leaks.
Do it now.

[Toomuch240]

gonna check compression this weekend

[Toomuch240]

Could my idle be a timing issue? checking compression tom forsure

[Ceepo]

check compression then get back to us with more Q's

[Toomuch240]

Ive got 0 comp on 4th cylinder :( 30 on my 3rd barely 100 on my 2nd and 90 on my 1st
cars a peice of crap -____-

[Toomuch240]

so an update on the car, i swapped the head out when i took the old head off i had 3burnt valves on each cylinder :goyou: put new head runs like a champ now ;D

[waynehead05]

^ dang. Well I guess go ahead and Seafoam the motor through the brake booster line to clean off the valves, and enjoy the improved performance.