The engine in my 90 C4 seems to be skipping when at idle and definetly has rough acceleration. Im thinking I have a bad plug, plug wire or maybe a fuel injector. I replaced plugs and wires about 2yrs ago and replace all 8 injectors last year.
So I have a day off coming so I thought Id start by replacing the plugs and wires, if for no other reason than TLC.

Are there any aftermarket plugs and wires that are recommended that would be considered an upgrade or performance enhancement to the OEM AC delco plugs and wires?

Thanks,

jwardg

I think troubleshooting would be better than just throwing parts at it. Those are relatively new parts. Check back later and one of the tech gurus around here will give you some solid advice, I'm sure.

Tommy is right...

But since you asked, I suggest NGK plugs and Taylor or MSD Wires.

With that said, the idle issues could as easily be caused by a bad or slow O2 sensor... or a clogged up IAC valve housing.

Check fuel pressure, also is it holding when the engine is shut off.
My guess would be fuel pump.

I'm going to assume there aren't super high miles on those items since you replaced them?

You can pull the easiest plug just to check it, but I doubt they need replacement. Wires should be good. You can run the car at night with the hood open or in a dark garage and check for any arcing. Make sure all the wire boots are pressed on snug and there is no insulation that is worn away and grounding.

Like Andy said, check the IAC, it is probably time for a good cleaning along with the rest of the throttle body.

As Axel pointed out, check the fuel pressure.

Another thing I thought of, what is the condition of the cap / rotor? Have you inspected those at all? They are also wear / maintenance items.

Hope that helps,

Matthew

Thanks for everyones, input. Well after doing all of the tune up items myself over the past four years(plugs, wires, distributor, injectors,etc)
I decided it was time to take it to a shop,and Im glad I did. They put it on a scope and found that I had two bad plugs, and one of the terminal pins on the top of the distributor cap was broken as it came off when they removed one of the plug wires. Plugs,wires,cap are less than two years old, so I was a little surprised, but sometimes diagnositic equipment can see what the eye can't. Anyway, its running better than ever. Still a work in progress, but Im enjoying the ride!

Good to hear!

excellent!

As for parts breaking... par for the course anymore... get good parts, MSD, AC Delco, might help mitigate that failure.

Same with plugs... NGK is my personal choice.

I just did wires myself. I got the MSD set you make yourself. Those are pretty cool, and they come with extra parts in case one of the wire ends come off. I will definitely use something like these from now on. Oh, and I have removed them several times now while troubleshooting, and no ends have come off.

Good job