missfire

[PCGUY112887]

Ignition Control Module? Is supposed to be a popular thing to die at high miles...

[pontiac3100]

i replaced that one...looks like it'll need to be replaced again.
i used chevron techtron.

it seems when i do use the cleaner the engine runs like this.
becuase she did do at all today on the way home from work.
but she did have that missfire...

how long would it take for the pcm start to rely on the o2 sensor.

'cause it seems that only thging it relies on when warming up is the o2 and coolant temp sensor.

and it seemed when the t/c would lock after a while you could smell the richness

[IsaacHayes]

http://60degreev6.com/showthread.php?t=37003 Info for spark plugs. Might help with some of the problem.

ICM usually goes wonky AFTER it warms up not before. Sounds like a fuel problem. How new is your O2 sensor BTW?

My car ran much better at low RPMs with a new O2 sensor and mpg went up and so did power.

Also mine was running a bit weird and I took off the EGR and noticed that one of the valves on it was stuck open... That's easy to check 5min job to unbolt it and look.

[pontiac3100]

as for the o2 sensor
i dunno.

and for your sparkplug chart i think i see the problem....there's no rapidfire chart in there.

i asked about the pcm relying on the o2 sensor, becuase i had the scanner hooked up and while in open loop it was showing 222mV.
then a few seconds later the readings started going up and down.

here's another thing when in WOT it feels like bogging...
and the "bogging" seemed to have come back when i used the chavron stuff...

[IsaacHayes]

There is a rapid fire plug listed at the acdelco site for a 94 era 3100 part number "6" with a .045 gap which is odd for the 3x00 motors. Is that the one you are running? I didn't put it on the chart because it wasn't factory plug originally, it just seems it was released later as a replacement on the older motors. I can't find the specs on that plug so I have no idea if it's platinum or what.

That injector cleaner may be doing something to your injectors maybe it's freeing up crud that is now sticking in them? I'd stay away from it then if it runs bad each time you do it.

[pontiac3100]

hell yea it's odd...in fact i even gapped them .060....

[IsaacHayes]

http://www.acdelco.com/parts/sparkplugs/rapidfire-platinum.jsp

Hmm says they are platinum, doesn't say if they are double. So if they are single eh... When you gapped them did you use pliers to bend or did you pry on the tip/ground? If so you may have damaged the platinum coating...

[pontiac3100]

might as well say....i used a sparkplug gapper.
hey! i see in your sig that your 3100 has 180k on it?

[IsaacHayes]

Yeah now it's 200,000 something. I'd have to dig out my old gauge cluster to find out exactly. I swapped to a full gauge cluster and it had lower miles and I never got it corrected. It sees WOT well, a lot. hehe

[pontiac3100]

whoa!
they can talk bad about gm engines....every engine have there flaws i rather have a lim repair than replacing the h/g evrytime

[pontiac3100]

hey was your car running or acting like mines before you changed the o2 sensor?

[pontiac3100]

bump,please

[pontiac3100]

okay another symptom...
it seems when the temp is below i wanna say 150*F, the engine seem to have this misfire....

[IsaacHayes]

No it just got bad mileage and smelled really rich. But other than that you wouldn't know it was running bad. After replacement it gets great mpg and is faster and more responsive to boot!

Yeah I've replaced the LIM twice on mine and caught it each time. Never let the car got hot enough to blow a headgasket. Most people think it's the headgasket on these motors when they see coolant leaking into the oil.

Check your Coolant temp sensor. Maybe it's reading that the car is warm when it's cold and causing it to run rough? Did you ever change the 24x sensor?

[pontiac3100]

okay i used the scanner.
and when you first turn her on koeo, the temp sensor is somewhat around the outside temp.

then you start her up.
and it starts to read.
i never replaced the 24x sensor, i removed the harness and the car was in open loop once she closed the engine hesitated then idled normally.
got no ses light either, but i had a code.
and was able to restart her.

yea tell me about it, this one guy i know who's a mechanic said these motors are shit.
i told him...hell no, no way these are.
she's been reliable, and can dust my friends 92 caprice.
and the only reason you think they're junk is becuase of the lim gaskets...thats gm's fault, not the engine.