As some of you who have helped me may remember, I soldered all the
splices I could find on my S-10 and all codes went away. 13, 22, and
45. My truck ran beautifully for the first time in the 6+ months I've
had it. FOR TWO DAYS!
Get this now - On the third day, I was coming home from work, 40 mile
round trip. All of a sudden, going up a hill the truck began to lose
some power and I thought it slightly stuttered, only then to start
rapidly and violently mis-firing and sputtering back fire through the
throttle body! pop-thud-pop-thud-pop-thud-pop very fast against the
air cleaner housing. Totally bizarre stuff. Of course I pulled over
to the side as I tried to keep it running till I could get under the
and pull off the air cleaner. I pushed the throttle open and horrible
harsh clacking and flames inside the intake manifold. The damn motor
sounded like it was going to fly apart. It died. I pulled the
positive battery cable for 30 seconds, put it back on, started it up,
and the misfiring was gone! WTF? For the next two days this truck
would do this midway to work and midway back. Each time I
disconnected the battery cable, put it back on and it was good as new.
WTF? Tonight on the way home, I took a long route and it didn't miss
once. WTF is going on with this crazy truck?
Pull the distributor cap off, remove the Ignition Control Module and take it
to Autozone to be tested. Backfiring thru the TB is caused by one thing, a
timing problem. Because it runs fine after resetting the ECM, this tells us
it's not a timing chain problem, the dizzy hasn't jumped a gear or the like,
but it's a problem with the electronic ignition system, which consists of
the ECM, the ICM, the inductive pick-up coil, the ignition coil and the ESC
system if so equipped. Start with the ICM.
OK, I'll have to get in the gm manual to identify what this is
tomorrow. I'm a little
bit skiddish about messing with the distributor though.
Yeah. I thought maybe the computer was probably bonkers. That that
the only thing that would tell the ignition when to fire, or misfire.
Thanks Doc, I'll read about all those things tomorrow. I'm close to
shit canning the
truck and cutting my losses, but that would be really hard to swallow.
Thats why I
haven't done it already. Well, that and because I'm thick headed and
when to quit.
Doc is right on. Had this exact symptom with my 90. After 250K miles, the
distributor and ICM were toast. Replaced the distributor, ignition coil, ICM
and she spins like new.
(remove NOSPAM to reply)
Hi Again Doc,
Well, I did decide to get the ICM, after thinking on it for a while,
it looked easy enough to handle. Though I could have bought the
entire distributor, with the ICM, pickup coil, hall effect switch and
all for just a little more than 100$. This ICM by itself was almost
I'll try to test the one thats on it before putting the new one in.
This stuff is difficult to do when you
only have one vehicle. Anyway, I got it cooling down with the hood up
I forgot to mention one other thing that might be directly related to
whats happening, and that is that
the "check gauges," light comes on every time I brake to a stop.
After sitting there for a minute, it goes out. None of the gauges
shows anything abnormal, so I don't know why this is doing this. I'm
wondering however if it might be someway electrically related to what
else is going on. I also found out that I don't have to pull the
positive battery cable to get everything back to snuff. Just sitting
with the engine off at the side of the road for 2 or 3 minutes does
the same thing. Something is getting hot. Wish I knew what.
As I thought I said, or implied, that would require me to get someone
to take me, or take a cab 15 miles.
Anyway, I replaced it. The old one didn't have any of the silicone
under it, thats supposed
to keep it cool. Finished it, no "service engine soon," light came
on, it ran flawless for
about 8 miles. Then it started missing again. Soon as it gets to
full operating temp I suppose. Only had a different rythm to its
missing and popping is all. Then
leaving it shut off for a few minutes didn't help, neither did
clearing the computer, as it did before. I tried it
at least three times. Drove it all the way home missing and popping
like a big dog.
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