Strange misfiring @ partial throttle ~30%, what gives?

[JDMSIL80]

It started to happen just a few days ago, for the first 20mins of driving it would misfire on me at around 3000rpm w/ 30% partial throttle just before the boost kicks in. The car jerks heavily because of this, but there is no misfire at WOT or lower throttle input.

I know it has to do with the temperature because after the motor fully warmed up the misfiring started to diminish. However, the situation is getting worse and it would longer for the misfiring to disappear day by day. My motor was fully warmed up but it still misfire on me.

Did I overlook something that should be done periodically that would cause this to happen? ie: plugs, maf cleaning...etc?

Thanks!

[rico05]

Vac leak? Mine does it when completly cold, but once warm, it runs fine.

[CA_OWNZ]

my ca has the exact same thing, cold is the worst, but if i run harder than normal, it will happen then too, it seems like its loading up with fuel? i know my O2 prolly isnt reading right cause theres a leak before the sensor, but other than that im not sure... any help would kick ***, thanks

[yourmomsrps13]

same here, i get some nice flames in the morning when its cold. mostly around 0 boost, alot of fuel.

[CA_OWNZ]

so would a good tune help this out? cause it frustrates me when im initiating and it starts hesitating, or i try to launch on someone and it bogs out before boost :-\ oh well if anyone has some advice, id greatly appreciate it

[JDMSIL80]

Seems like a common problem for the CA owners, does anyone have a solution out there to help us out?

Im thinking it could be the copper spark plugs Im running, since its already been almost 3K since I last changed them.

[rico05]

so would a good tune help this out? cause it frustrates me when im initiating and it starts hesitating, or i try to launch on someone and it bogs out before boost :-\ oh well if anyone has some advice, id greatly appreciate it

If you don't have a boost leak (leak after the turbo) then your timing is off. Try resetting it.

[beans33]

Mine does the exact some thing as everyone else. It just kinda bothers me because it will only happen when i start it up and it hasnt warmed up yet. The other day I was running late and pulled out into traffic and what does it do just bogs and sputters and then around 3800 (gtir t28) rpms it will jsut take off, i almost got plowed in the rear end. But after it warms up it drives like a champ. I just figure it has something to do with o2 warming up or temp sensor. I dont know though ????

[MikeDombeck]

mine does that also but the ECU flashes Knock Sensor, so i dont know...... i changed my plugs, coilpacks, and vaccume hoses, and it still does it, so its the sensor in mine..... just thought id share

[rico05]

mine does that also but the ECU flashes Knock Sensor, so i dont know...... i changed my plugs, coilpacks, and vaccume hoses, and it still does it, so its the sensor in mine..... just thought id share

Make sure that the knock sensoris wired properly into the main harness. Mine was not and it pulled timing. I have changed my coolant temp sensor (ECU one, not cluster one) as well as the O2 sensor (as a matter of fact, I just changed the O2 sensor, plugs, and reset the timing about an hour ago) and mine still does it. I too have the bog until 3800 rpm issue, which leads me to think that since the injectors go from sequential to batch fire at that point, it must be an injector issue. Possibly the the ECU has a hiccup. Or it could be the FPR. Or the injectors themselves. It drives me nuts that so many of us have this issue!!

[NeedCAforS13]

mine throws no codes, but does this. only to a slight degree though, nothing thats really even noticeable to anyone riding in the car. I just notice its kinda "rougher" feeling when the motor is cold and with partial throttle.

[Ca_Silvia]

mine throws no codes, but does this. only to a slight degree though, nothing thats really even noticeable to anyone riding in the car. I just notice its kinda "rougher" feeling when the motor is cold and with partial throttle.

Me too, (T28) i throw no codes and it runs like *** when cold and "weak" when warm. I was thinking timing too as i just did the timing belt recently and it hasn't been the same since. I was going to finally get an ECU chip for the bigger turbo and i was kinda hoping that would solve it.... ill have to wait and see

Crazy how so many people have this problem

[rico05]

For me, it is kind of a necessity to warm it up because I run 15W-50, an oil cooler, and no thermostat

[ragenasian]

Me too Me too, mine does this also. It actually won't start when it is really cold. My last CA ran great cold or hot, but wrecked it. Now the new one with the rebuild won't run until warm. It will also backfire when I try and stomp on it, it bogs out. If I go about half way it back fires. If I ease into it, it will go up in rpm. Everything seems to be working on the motor, and my mechanic couldn't figure it out either

[CA_OWNZ]

ok, ive been watching my SAFC when this happens to me, it seems as if, when misfiring/studdering or w/e the motor is getting starved of air, the AFL% drops, and with more throttle the % drops, especially when cold. So im not sure if that is anything to shed light, but if anyone has tips, and btw, where is the ecu? dont mean to be a noob, but i need to check if any of those lights are flashing

[float_6969]

The ECU is located in the passenger side kick panel.

[Ca_Silvia]

Well i hope this may shed some light for you other guys with this problem but i clean the MAF and re-torqued all my spark plugs to the FSM reccomended 15ft/lbs and bingo its all good! I did do them one at a time in order to see which did a better job and the torqueing of the bolts made the best improvement. So try it out might work

[gore]

me tooo damned ca's!