please help me

toddw814 · Post by **toddw814** » Fri Nov 13, 2009 12:20 am

ok so i have a 2.0L SOHC and recently with in the past two days it started to missfire . but its wierd ok first off i change spark plugs and coil pack but it only misses from between 1000 to 2500 rpms in all gears but if i put it in park or nuteral and slowly rev it high it has no problem it goes up and drops very smooth and easy .
if i am rollin slow an mash the gas like i said it clears up after 2500 rpms and runs smooth until redline and its like that in every gear
i was thinking maybe a fuel prob like injector but it would do it if i mashed the gas to ,and it dont , and fuel filter it would be steady and fuel pump, well it just wouldnt run .
but i also thought it would be the same with spark
then i thought maybe the fuel regulator sensor or the mass air flow sensor or even maybe the O2 sensor
oh yeah it also back fires to when it starts missen.you can hear it up by the header which i do beleave means its running rich but dont quote me
if you can help it would be so appreciated

ragek23 · Post by **ragek23** » Fri Nov 13, 2009 1:27 am

just to clarify you mean misfire?

FAC3L3SS · Post by **FAC3L3SS** » Fri Nov 13, 2009 1:33 am

r/tguy02 · Post by **r/tguy02** » Fri Nov 13, 2009 7:57 am

no codes?

Post by **occasional demons** » Fri Nov 13, 2009 8:05 am

Can still be an injector. It may not be delivering enough fuel under those conditions, when you go WOT it's duty cycle increases. (Stays off the pintle longer) If the injector's coil is failing, or it is getting clogged it could do this. Are you getting a CEL or some kind of code/ (P0300/P0301/P0302/P0303/P0304) If you can determine what cyl's are misfiring, then swap the injector positions, to see if it follows.

If it was a valve hanging, it would get worse with more rpm. There is no fuel pressure sensor, our PCM's are speed density, so no mass airflow sensor.

A bad MAP sensor is another possibilty.

The TPS/MAP/IAT/coolant temp sensors contribute to the speed density calculations.

Mat · Post by **Mat** » Fri Nov 13, 2009 9:14 am

I agree, I'd eliminate the injectors first too. I'd look at the throttle position sensor after that.

toddw814 · Post by **toddw814** » Fri Nov 13, 2009 8:46 pm

well it hasnt thrown any code till today the check engine light never came on so i took it to auto zone and its miss firen on cylinder 1 so that tells me its got to be a spark prob or an injector so as soon as i get paid im getting atleast one injector untill i can afford them all
but im gonna try switching them around to see if thats what it even is
if you disagree with this please let me know and give me your advice
i appreciate the help to

ragek23 · Post by **ragek23** » Sat Nov 14, 2009 1:57 am

there is a code for an injector not firing so i am thinking u should check your spark first.

Adionik · Post by **Adionik** » Sat Nov 14, 2009 4:21 am

You changed plugs and coil, how about wires? My SRT did this and it was the wires.

toddw814 · Post by **toddw814** » Sat Nov 14, 2009 2:15 pm

that what it was
was the wires
for the number 1 cylinder

BlackRoseRacing · Post by **BlackRoseRacing** » Sat Nov 14, 2009 4:33 pm

problem solved?

toddw814 · Post by **toddw814** » Sat Nov 14, 2009 4:35 pm

yes thank you for all your help