My '98 has a lot of trouble with distributor caps. When they go it starts hard and it has very little acceleration. Think I've put 3 on it in 3-4 years. When I first got it, it could be pretty temperamental when it rained really hard too. Why I changed the cap the first time.
They are notorious for that problem, especially if they sit a lot.
Here's a potential solution to your problem.
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"GM Vortec V-6 & V-8 engine Application Alert
1997 and newer GM vehicles equipped with “Vortec” type engines may experience misfires
and hesitation due to moisture accumulation inside the distributor cap and a general lack of
airflow inside distributor. GM TSB #03-06-04-041A & #05500 involves 2001-2003 vehicles
however, the condition may occur in earlier and later vehicles. Whenever servicing a Vortec
distributor the following should be performed:
1) Inspect and clear 2 distributor vents on early models. On later models with vent screens, the 2
screens should be removed.
2) Check for coolant leaks near distributor from heater hoses or other sources of potential leakage.
3) Inspect PVC system and change engine oil on schedule. Moisture in pressurized crankcase vapors
can be forced up distributor shaft and contaminate the cap and rotor causing internal arcing and
corrosion.
4) If A/C equipped, insulate accumulator line near distributor base. A 9 inch long piece of foam having
an internal diameter of 1.25 inches and .25 inch wall thickness is recommended."
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If the vents in dist are clogged it can cause corrosion and arcing (erosion) due to moisture.
There's a consensus among those "in the know" that AC Delco ignition parts are the only way to go. Aftermarket dist caps and rotors are notorious for
eroding faster than OEM. I bought a Napa Gold cap and rotor for my 98 chevy and it looked like crap after 30k. The original cap and rotor looked better at 100k than the Napa parts.
It's also possible that there could be other weak ignition components that might cause problems with excessive erosion.
I'll add this too. The best place on the internet for info on chevy trucks is fullsizechevy.com. It's great forum with many knowledgeable folks that are happy to help.
It's just like the fire.
