fp1529

I have a 99 1500 Suburban 2 wheel drive 130,000 miles no engine code light. My truck started missing several months ago, I noticed it did this when it was wet outside. I checked the distributor cap and found corrosion on the metal points. I changed the cap and button and it ran fine for a while then it stated missing again when it was wet outside. I put another cap on it and it ran fine for a while. It started missing again today early in the morning driving to church, it was not wet outside beside the morning dew, after church it ran fine driving home. I looked for cracks and places where water or moisture could get in and did not see anything. HELP!

Jeremy-WI

You might need a new pcv valve. I think there is supposed to be a vent in the bottom of the distributor housing to let it breathe

j cAT

I recently had a vehicle that had a distributor cap problem like yours////the windshield washer hose was squirting washer fluid at the distributor....

cap/rotor/wires replaced....silicone dielectric grease on all wire boots....

fp1529

Thanks I checked the washer fluid and PCV valve they are okay. I do not have a gasket between the cap and where it seats, is there supposed to be one? Can I use a liquid gasket if dealer does not have one? Last question why would the truck miss in the morning but not in the afternoon? Can the humidity cause the distributor miss?

j cAT

the moisture problem inside the cap is saying the cap must not be installed correctly or water is being directed into the distributor area....

did you use dielectric silicone grease on the plug wires boots ?
also use this grease on the base of the cap....

this is begining to point to bad plug wires/improperly routed wires....this is common as when the plug wires are replaced they are not put back where they belong,,,if necessary use new loom/tyraps to keep wires at the proper position...

excessive plug wire resistance is also a cause of arcing ...this resistance slowly overtime may be 3x the OEM spec..then the voltage starts jumping at any ground point instead of the plug tip.

fp1529

Thanks for the help. J Cat I did find a wire that was not snapping tight on the distributor side and it was sliding loose. I have NAPA wires on it now and the mechanic snapped an unknown used one in place of the defective one to see if it fixed it, and so far it has. I am going to replace all of them with AC Delco soon. Again thanks for the help.

j cAT

the delphi wires are the correct wires to get,, they are an exact fit ///this is the problem when wires are an aftermarket type incorrect fit/boot end..

always measure the wire resistance of new wires,,,this will prevent surprises..