'98 Malibu - idling problems in wet weather

Hello and TIA for any help. My '98 LS 3.1 has just over 90K and has had no performance issues up until now. As a result, it also has not had a "tuneup" since I bought it at around 46K. Lately in rainy
weather, after a few minutes of driving the car will sometimes fail to accelerate away from a stop, bucking and surging. Or, it may stall altogether once or twice while idling. This occurs *only* in wet weather, *only* after being driven a mile or two, and *always* ceases once the car is fully warmed up. I replaced the battery since it was time anyway, but this had no impact.
Has anyone else seen this particular behavior? Any recommendations where to start?
thanks Steve L.
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| Hello and TIA for any help. My '98 LS 3.1 has just over 90K and has | had no performance issues up until now. As a result, it also has not | had a "tuneup" since I bought it at around 46K. Lately in rainy | weather, after a few minutes of driving the car will sometimes fail to | accelerate away from a stop, bucking and surging. Or, it may stall | altogether once or twice while idling. This occurs *only* in wet | weather, *only* after being driven a mile or two, and *always* ceases | once the car is fully warmed up. I replaced the battery since it was | time anyway, but this had no impact. | | Has anyone else seen this particular behavior? Any recommendations | where to start? | | thanks | Steve L. | |
Could be ignition wire fault. With the engine running on a damp night, pop the hood and cut any illumination so that it's dark and look to see if you observe a light show under the hood. If you do, the ignition wires need to be replaced.
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"S.L." wrote: '98 Malibu LS 3.1
Bought at 46K, has 90K. No tuneup since purchase, always ran fine.
But now, in RAINY WEATHER ONLY:
1.) Starts good, runs good for a few minutes, then runs rough. 2.) After full warmup, smoothes out and runs good again.
Any recommendations where to start? Steve L. ____________________________________________________
It is probably high voltage breakdown.
1.) Moisture on ignition parts (Distr cap, plug wires, plug insulators) provides easy path for firing current to go to nearby metal rather than across spark plug gap.
2.) Widened plug gap in old plugs is harder for spark to jump.
3.) Old ignition parts have deteriorated insulating abilities.
4.) Richer mixture (easier to ignite) and higher idle speed when first started permits relatively smooth running.
5.) After mixture becomes leaner and idle speed is lower, roughness intensifies.
6.) Full warmup dries moisture from ignition parts and improves insulating ability and smoothness returns.
I think it's time for that tuneup.
Good luck
Wendy & John. _____________________________________________________
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On Fri, 01 Oct 2004 00:39:42 GMT, "S.L."

One thing that I must comment on is the mileage. We bitch about how crappy cars are being built nowadays, but I don't know of any points & condensor system that would even be running at this point. I must say that I do love technology with regards to how it has helped us keep our cars longer.
PS this one probably just needs a tune up.
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These had a particular problem with the spark plug wires don't fit tightly enough on the coil pack and it causes arcing and eventually leakage especially when wet. One at a time, remove the plug wires from the coils and look at the coil terminals. The may be rusted on the terminals that don't fit tightly enough. I have seen people sand off the terminal then bend the plug wire connector to fit tighter. But the right way to fix this is clean off coil terminals till shiney, then replace plug wires using die-electric grease on the terminals. If you want to prove if this is the problem, just get some die electric grease and put some on every terminal to see if the problem goes away before changing wires. Although if they are original anyway, it is time for replacement.

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S.L. wrote:

Give the poor thing a COMPLETE tune up. It's a wonder it runs at all.
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Replace the air filter.

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