Cap& rotor

i have a 1999 chevy silverado 4x4 with 37000mi, 4.3l v6. for the last 4 years i’ve had to replace the cap & rotor annually, you could almost set a clock as to when it’s needed! any suggestions???

what has been the cap and rotor failure diagnosis? cracking, arcing?

i would suspect an inferior brand of cap and rotor. have you switched your supplier? A replacement at this mileage is suspect of a further down the line problem. has any other work been done on the engine? Possible the rotor shaft is bent, broken, or loose helping to cause this issue.

is this a rebuilt engine? or is the mileage a typo? if the mileage is true then at an average of 3700 miles per year would indicate this vehicle sits around for a long time between uses. im wondering how such low use would contribute to this?!

Try replacing the cap and rotor with one from AC Delco or Delphi. Also I believe there is two vent screens at the bottom of the distributor that if clogged will not allow moisture to escape, thus causing misfire. Remove or clean these screens if applicable.

If the cap and rotor are being damaged from arc burning, the problem might be with the ignition module.

Ignition modules function in two modes. These are the start and run modes. When starting the engine the ignition module allows full battery voltage to the coil to ensure the cold engine starts with a rich fuel mixture. Once the engine starts and the ignition switch moves the the run position, the ignition module steps the voltage down to the coil because not as hot of a spark is required to keep the engine running. And this also prevents damage to the secondary ignition components.

If the ignition module fails to switch to the run mode and remains in start mode, this excess voltage to the coil will damage secondary ignition components. ie: Cap & Rotor.


no rebuilt engine, mileage is correct, i use vehicle everyday, just not very great distances, thank god for stainless exhaust system. my garage of 40 years have been doing the work, they suggested ignition wires, all are original, plugs, wires etc. runs like a top hate to change anything if not needed. thanx for prompt reply, i’m getting several ideas, garage switched from STANDARD supplier back to EKLON which i believe is a name brand.

thanx for prompt reply, as you can see i’m getting several ideas! will have to wait for the weather to break to check vent screens!

will bring it to my garages attention, hate to replace if not needed, once you mention it’s as good as done! thanx for prompt reply, getting several ideas as you can see.

On most cars replacing a cap and rotor is very easy. If there is nothing else wrong with the motor you can buy these items at any auto parts store, even WalMart and install them yourself.

Take the old cap off and move it aside enough to change the rotor and put the new cap on. Then move the wires one at a time making sure to place each on the correct point on the new cap. Take a look and see if you feel you can handle this yourself.

thanx for prompt reply, it just seems something must be causing this and as i stated it happens annually, jan in buffalo!