My 95 Pontiac GrandPrix with 3.1 is surging. Not bad, VERY subtle. I
have no error codes, other than EGR (I know I have a clog) but the surge
is under light acceleration, and the EGR shouldn't affect that.
Anyway, I'm gonna try a soak-out of the EGR this weekend if the weather
is nice and I can work on the car. For the surge issue, I'm thinking maybe
just shotgun with new plugs, and possibly test the wires to see.
Anything else obvious to go for? If plugs don't help, I may just try new
As far as I can tell they are original with 135K on them.
Well, I did some work Saturday before a trip and pulled a couple of the
They looked fine, as far as I could see. They were Bosch Platinum. No
no flaking. The wires were also Bosch Super something or other, and I
see any signs of cracking or leakage. I didn't go so far as to spray them
mist from a Windex bottle and then slide a neon bulb up and down, but they
Anyway, I also pulled the digital EGR valves off. I started the car and
carb cleaner in the intake. It seemed to 'open up' and start sucking. I
back on and no 'service engine soon' light. Until today. Took over 100
and it came on as I got off the highway and came down an exit ramp after a
50+ mile run. So I may have to do it again.
Oh, I also put some injector cleaner in the tank, and the surging seems to
stopped. At least, I didn't notice it. But then, I didn't specifically try
for it or set up the conditions where I know it was more likely to happen.
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