2.4 random missfire

[chayito95]

new guy here

2.4 l oldsmobile alero automatic

the problem.. random missfire, sluggish at wot sputtering. regular missfire as i have seen on this site.
So here is what i have done, bought new coils and plastic cover. checked injectors they check out fine.

engine blew there after.

Bought new engine, again same problem, bought new pcm fixed problem temporarely. so i went over everything agian from spark plugs, coils, boots ICM crank and cam sensor, coolant, tps, iac, and o2 sensors they are all within spec. Yes i used a voltmeter. I also checked for vacum leaks found none i checked the cat, thought it was clogged ran it with out it and no change.
so Im basically stumped i dont know where else to check.. i havent gotten around to checking the codes the new pcm has thrown cause the car wont make it into town to my nearest autozone.
any ideas would be much appreciated

thanks

[Gr1m]

go to autozone and buy a code scanner they are only around 25$

[Alerosaint]

check wiring or pcm connectors.....awesome alero dedication tho

[GA_turbo]

how many miles were on the car when it started doing that and what year is it ?

check fuel pressure, check fuel regulator and im leaning to a bad fuel pump.

[chayito95]

ah yes.. it is becoming quite a pain actually.
I checked the pins on the ecu as well as on the connectors at the harness they all check out ok. I forgot to mention that i had already checked the fuel pressure and that check out ok, bought a new regulator for ish and giggles and nothing. Fuel injectors check out ok on resistance according to my book and info i found here and online so i really dont know.. im gonna try doing what you guys adviced and buy the scanner maybe that will point me out.. i honestly dont know what else to replace.

ha ha the car had 145k when it started missing, blew out at 151k the new engine has 98k so its an upgrade persay..

thanks for all the input here

[chayito95]

Hey, me again just an update here for those who may be interested.

All my research lead me to quad4forums.com where i found a mod to the ignition system on the quad4 engine.

well long story short i got an ignition set up from a 95-99 mitsubishi eclipse non turbo 2.0 l. This fixed my problem the ignition set up on the 2.4l quad engine is efing retarded.

anyways those interested in this
http://www.quad4forums.com/forums/sh...ad.php?t=13027

[undersc0re]

Originally Posted by chayito95

Hey, me again just an update here for those who may be interested.

All my research lead me to quad4forums.com where i found a mod to the ignition system on the quad4 engine.

well long story short i got an ignition set up from a 95-99 mitsubishi eclipse non turbo 2.0 l. This fixed my problem the ignition set up on the 2.4l quad engine is efing retarded.

anyways those interested in this
http://www.quad4forums.com/forums/sh...ad.php?t=13027

Ya the coil housing and cover and boots have some sort of problem there, I had it replaced and it was good, but every once in a while it leaks spark to somewhere especially under load, I am wondering if I remote mount the coil and housing and rig up some quality spark plug wires if it will help with some power and gas mileage...it would be an ugly setup...lol

Its very easy to do heres some pics of mine