missfire

[pontiac3100]

nope this time i think it's the gauge on the cluster....
becuase when i stop quickly, or tap on it.
it'll act up.
also whenever my system hits a bass note the gauge whould jump.

at first i found it cool.
thinking damn she loves some reggaeton or rb etc. but after that cruise control incident....


i think it's the cat too.
now that i think about it it seem the bogg or chokes goes away after driving her....which probably means that the pipes expand more letting the exhaust out?

[pontiac3100]

okay now the "bogg" is gone.

all i have is the misfire when cold and when the t/c is locked.
i do notice that the injector pwm is higher than before.

with a/c off and 220*F it's 4.2+/-.
before it was 3.5+/-.
while flooring it though i get that smell...i think from the cat.

[torq455]

are those 3.5 ms at idle? cause mine are about 1.2 ms

[pontiac3100]

was 3.5 now it's about 4.2+/-.
and it does'nt change with the a/c on but the idle does go up.

and if your talking about the hot ass cavy in the pic....is'nt it 'cause your's sprays 3 at a time??

[pontiac3100]

bump

[torq455]

hmmm good point, i believe so. are you referring to my cavy? the white one? I wouldn't call it hot ass, but it is VERY nice in and out. i take it to a GM dealer and they really want me to trade it in hahaha, fools, NEVER!!!!

i do remember an SFI with a higher pulse width it was close to what yours is at, but the pulse should increase a little with load.

[pontiac3100]

yea i just remebered she's does.
in fact at idle she's in the 3's.

but i guess she learned because when the a/c was on in drive it whoul dbe in the 5's.
and man let me tell ya...i would noticed the gas going.

now it does'nt and i have'nt been babying her (well maintaining wise yea).

but i noticed today the smell and it lasted till the gauge reached 220*F.
but i could only smell it at idle.

[torq455]

i think it's safe to assume the converter is bad. usually the converters work when they're hot. trying to remember.....running too rich will plug the converter with carbon, and running too lean will overheat it? if it's pluged, it may provide too much back pressure forcing more exhaust gas through the EGR when working, and maybe causing a lean condition causing a missfire intermittently depending on throttle position. I'm reaching a little here but it does make some sense.

[pontiac3100]

WHAT!!!!!!I HATE A LEAN CONDITION!
IT'S BAD FOR A ENGINE.

well i can determined what happened though (if it's the cat)
well less see
the previous owner did a lot of highway miles took care of the car, then gave it to her son who had the car for a year.
seeing that the engine had a feature where you can replace the plugs at 100K miles (bs anyway).

i replace em and they're no good.
use cheapo ac delco's and the engine burns em out in about 1 to 2 months.
get some rapid fires which did'nt do to well.
find out i'm supposed to use platiums.

then the pcm blows out choking the engine.
replace it while reping pcm after pcm, find out i'm SUPPOSED TO USE 94 gt pcm and NOTHING ELSE.

finally get the right pcm...now the plugs are no good.
when first stating her up while cold she missfires.

well your kinda right on the cat.
when there's only raw fuel (misfire's when cold) going into the cat plus heat makes the cat over heat....leaning will do the same.

does that make sense??