High resistance plug wires, or excessive plug gaps aggravate the leaky rotor issue. Easy to see, flip the rotor over. Look for a little black dot below the blade. Spark goes to ground on the distributor shaft. I like Echlin (NAPA) caps, brass tabs inside, instead of aluminum. Most of my regulars never went anywhere else, so I got to see a lot of this stuff long term. As I have mentioned before: don't go buy anything at Autozone with a wire going to it. <G> Might notice that the better shops in your area doesn't buy much there. If there is a NAPA, you will find more shop owners more than the DIY guys you mostly see at Autozone. You get what you pay for. Same for most things in life.

Edit: forgot to mention: in damp weather I saw a lot of wet caps. Sweating. I began to save old caps, to cut pieces to make a cover to epoxy over one of the two square intentions at the top. For a wire retainer that I never saw used. I drilled a 1/8" hole in the one facing the firewall. Then epoxied the piece I cut off an old cap to cover that intention, but for a gap at the bottom. That way guys could wash their engines without water getting in that hole. The hole came through near the top, between plug wires. The rotor going around moved air well enough it completely stopped sweating caps.

 

That's great info ed.. I have a Napa about a 45 minutes away and the auto zone is the only local one . I'll swing over there this weekdnd

Just curious as to what you think about putting a barbed vacuum line where you drilled your 1/8 hole to the intake so it has a vacuum applied to it like the opti?

I noticed my cap and rotor always would go bad on high moisture days.

What do you like for plug wires and plugs on these motors?

I'm gonna rip that cap and rotor off this weekend, paint the terminals with gold nail polish and return it to auto zone

 

Ask for the good Echlin parts. They now have a cheap line of **** too. Don't buy that stuff. Don't know about the vacuum hose deal. Never saw a problem after I started venting the caps in about 1997.

 

Thanks

 

Great info from Ed!

Back in the day, Standard Motor Products offered almost any cap & rotor in their upgraded Blue Streak line. They make a Blue Streak rotor for these engines but not the flat cap.

Accel makes a pretty decent cap with brass terminals and hollow rivets for the hold down bolts and it's available at AutoZone.

Today, the best cap & rotor for this (V-8) engine is from MSD, part number 8017.

You can get zero ohm wires from the good folks at Granatelli Motorsports.

This was my setup on my 4.3 S10. It ran best with the Accel cap, Blue Streak rotor and Granatelli wires. Strangely though, it killed NGK spark plugs. Swapping to the "correct" ACDelco plugs cured that problem.

For the V-8:

 

Older TBI trucks have the same cap & rotor issues, same fix.

 

As far as health problems with mine affecting mileage, I don't think it has any compression issues as it has zero smoke and fires up in less than a second no matter how cold it is, so I think compression is fine. I'm starting to think I need O2s because it threw an O2 sensor SES light once but I cleared it and it hasn't come back. That and ill clean the MAF, see if that helps it. It has no misfires, stumbles, anything, but it does feel lazy below WOT, like the power is not linear as I ease the throttle from 1/4 to full, but ive never had another vortec to compare it to. At least in LT motors I know the PCM doesn't look at O2s at WOT, could be a failing O2 causing it to be rich at less than WOT, causing my bad fuel mileage, or the poppet valves are getting tired and not moving as fast causing it to be rich, I've heard of guys getting 2+mpg improvement going to the new electronically controlled spider.

 

The PCM does not reference the O2s @ WOT, but like anything else, if it has positive fuel trims at part throttle, it adds that same percent of fuel @ WOT. I shut that off in all LT PCMs, but have not tried to hunt that down in the Vortec trucks. Simpler to correct the fuel trims to zero/-5%. Dirty MAF (K&N oil), after market "cold air kits" (even though the factory air ducting is cold air) and weak O2 sensors all contribute to rich conditions.

 

Not buying this either after having swapped gears in 2 vehicles and buying a 3rd with the tow package gears.

On my 2006 Ram I went from 3.55s to 4.56s and did not hurt my mileage at all. I blame the 33" tall 20s and a 0.67 od for lugging the Hemi with the 3.55s to the point of drinking fuel.

On the Express van I went from 3.42s in a 10-bolt and a 4L60E with a 0.7 od ratio to a heavier 9.5" 14-bolt with 3.73s and a power robbing 4L80E with a .75 od and really cannot tell it lost anything mpg wise. If it lost anything it was less than 1/2 mpg. I put a bigger cam and ETecs on it a few thousand miles after I did the trans/rear. Last trip I pulled down 18.5 mpg running 70 mph most of the time. That being said I still beat the EPA ratings for a 1/2 ton van despite being lower geared, hot rodded engine, no egr and being a heavy conversion van.

 

So, just pull it down in 3rd, right? Don't need no stinking overdrive! LMBO!