93 Gran Prix intermittent problem

'93 Gran Prix, 3.1, 120K miles, mom's car.
Engine will run perfectly for a time and then suddenly lose power,
idle very rough, and then after a short time it will come out of it
"instantaneously" --which suggests to me it's something electrical
rather than fuel related.
She says she smells fuel when it's doing this.
Took it to a dealership, described the symptoms, and they couldn't get
it to act up on them (of course), but they changed plugs, wires, & fuel
filter, just because it had never been done in 120K miles.
The car's not had anything but a battery and tires replaced since she
bought it at 59K, so I'm quite sure nothing's been done to the car other
than what we've done.
I knew that making the above mentioned repairs wouldn't address the
way the car had been acting, and it didn't.
I'm wondering if it's not a coil pack going bad, since it had original
plugs and the coils have probably been working WAY overtime trying to
fire those worn out plugs which probably had huge gaps by now.
That's kind of how it runs when it's acting up--like one of the coil
packs suddenly delivers weak spark, then snaps out of it.
BTW when it first happened, it had just gone on a long drive on
interstate, 3 hours at 70 mph, stopped to eat, came out and it would
barely run. Then it just snapped out of it and ran fine all the way
home until sometimes when I'd stop at stop sign, it would run very rough
and then I could give it gas and after a short time it'd instantly snap
out of it and have full power.
Is that typical behaviour of a bad coil pack, ign module, something
else..?

James Goforth wrote:

'93 Gran Prix, 3.1, 120K miles, mom's car.
Engine will run perfectly for a time and then suddenly lose power,
idle very rough, and then after a short time it will come out of it
"instantaneously" --which suggests to me it's something electrical
rather than fuel related.
She says she smells fuel when it's doing this.
Took it to a dealership, described the symptoms, and they couldn't get
it to act up on them (of course), but they changed plugs, wires, & fuel
filter, just because it had never been done in 120K miles.
The car's not had anything but a battery and tires replaced since she
bought it at 59K, so I'm quite sure nothing's been done to the car other
than what we've done.
I knew that making the above mentioned repairs wouldn't address the
way the car had been acting, and it didn't.
I'm wondering if it's not a coil pack going bad, since it had original
plugs and the coils have probably been working WAY overtime trying to
fire those worn out plugs which probably had huge gaps by now.
That's kind of how it runs when it's acting up--like one of the coil
packs suddenly delivers weak spark, then snaps out of it.
BTW when it first happened, it had just gone on a long drive on
interstate, 3 hours at 70 mph, stopped to eat, came out and it would
barely run. Then it just snapped out of it and ran fine all the way
home until sometimes when I'd stop at stop sign, it would run very rough
and then I could give it gas and after a short time it'd instantly snap
out of it and have full power.
Is that typical behaviour of a bad coil pack, ign module, something
else..?

EGR is probably all gunked up.

Check engine light on? Sounds like its more of an electrical problem to
me. Ignition modules that go bad, act this way sometimes. Nothing like
having a F'IN dealership throw parts at it! Worse than lawyers!!!

No check engine light. I went ant talked to the tech today, seemed
competent, ben there for 11 years.
I went there to describe how it acted since it didn't act up for him
and he's getting his info from a 79 year old lady.
But he had just driven it and it finally did do it and he thought it
acted like maybe a bad coil pack.
So anyways...she comes home with it this afternoon and they installed
3 new injectors..said they were "weak." And maybe they were, but--say
it with me-- it still acted up on the way home.
In all fairness to the dealership, though, I thought it was a bad coil
pack and so did he, and he ruled out those for a reason.
Another poster said the egr could be gummed up, now I think that might
be possible, although I'd think there'd be a MIL for that.
I found the one on my '89 2.8 multiport to be stuck solid, although it
ran fine, put another one on and it wouldn't run right until I plugged
off the vacuum to it (what's up with that)?

If the mechanic also suspected the coil pack why were only the
injectors changed and not the coil pack. The ignition module is
integrated in the coil pack. If they are going to start throwing parts
at it, tell them to start there. Jim

injectors changed and not the coil pack. The ignition module is
integrated in the coil pack.

No it's not.

Now I'm thinking it's just the cmputer itself, putting the timing way
out of whack or something, no MIL due to this..?
That happened to my '89 2.8 mpi once.
Will post findings.

Timing signals below 400 RPM come from where Big Steve. Atta Boy./..
Knew u could figure it out! Change the coil pack or ECM to fix prob. Jim

Timing signals below 400 RPM come from where Big Steve. Atta Boy./..
Knew u could figure it out! Change the coil pack or ECM to fix prob. Jim

I got you a present for Christmas, a free subscription to my killfile.

Merry Christmas.

Your Pal,

Steve

Problem was a bad ignition module. I guess it logically follows that
you'd get no MIL for this.