I bought a 92 coupe in Jan with 46K. I been replacing stuff (hosed, thermostat, serpintine belt fuel filter). The manual says that the plugs are good for 100K. I am thinking it would be a good idea to change them.

What has been your experiences with sp wires ? any suggestion on type of replacements. I have a stock LT-1. Just looking for good stree performance. Also is this a manageable project for a week end mechanic ?

 

If you're not planning any extensive mods, I think the O.E.M. Packard wires are just fine. Ditto for the stock wire looms.

 

Are you saying to replace the wires or that the current wires are OK ?

 

How many miles on the car? Check the condition of the wires. If you're planning on changing the plugs, it might be a good time to swap, especially if they are showing signs of age or deterioration.

One way to check for plug wire misfires is to open the hood of your car, start the engine, and look for any telltale sparks jumping off the wires.

 

I seem to have had good luck with Belden wires from NAPPA. Another way to test your plug wires..if you have an OHM meter, they should ohm at 5000 per foot, just remember they are not 1 ft, 2 ft etc., odd lengths 1 1/2 ft. should read around 7500 ohms. I like to twist mine while checking to make sure there good.

 

The OEM AC Delco wires from a Chevy dealer are high quality parts, and they will be exactly the correct length, and will fit correctly into the wire looms. There is no reason at all to not use them on a stock street cruiser.

Changing the plug wires on an LT1/LT4 Corvette is not a lot of fun, but it can be done. Here are a few tips:

1. Raise the front end of the vehicle to a more comfortable working height.

2. Remove the inner fenderwell center panel on the driver's side. This will allow you to both see and do the job much more easily on the driver's side. You may also find it helpful to remove the wheel.

3. Unbolt the ASR bracketry from the frame, so that you can slide the ASR unit around to get it out of your way.

4. Unbolt the power steering pump so that you can move it forward around a half inch. This will make it much easier to sneak the plug wires in/out behind the pump.

5. Remove the serpentine belt and tensioner.

6. Use dielectric grease in the boots at both ends of the wires. Be sure to "burp" the air out of the boots after you get each of them pushed firmly into place, so that the trapped air doesn't try to push the wires off later.

Some guys report that they've had decent success accessing the Opti-end of the plug wires from underneath of the car, and that this saved them the trouble of removing the belt and tensioner. I haven't tried this, so I can't comment.

Take your time, work with care, and pay attention to what you're doing. The OEM replacement plug wires from your Chevy dealer are high quality parts, and will route (and fit into the wire looms) correctly. Run the new wires properly, and make sure they stay away from anything that moves, is sharp, or gets hot.

The passenger's side is not such a bad job. The driver's side is a Queen Royal Beyotch (mostly because all of the belt-driven accessories are hanging on the driver’s side of the front of LT1/LT4 engines, and they leave little room for you to work or see what you’re doing). With plenty of patience, beer and Band-Aids, you'll get it done.

The spark plugs on the driver's side aren't so bad, when you've got things apart to do the wires. The passenger's side, however, is not so easy. The number 8 plug in particular can be a real headache, but with good tools and enough patience, you can get it done. Because there isn’t room for a ratchet on top of the spark plug socket, I use a plug socket that has a hex head on it so that it can be turned with an open end or box end wrench. It's useful to have more than one plug socket to choose from, as some will work better than others due to differences in length, wall thickness, etc.

Be sure to apply a small amount of anti-sieze compound to the threads of the new plugs before you install them so that they won’t seize in the cylinder heads in the future (this is especially important with aluminum heads). Just make sure none of the compound gets onto the electrodes or insulators of the plugs. I apply a very thin stripe of compound across the threads in one spot, and it spreads itself around the threads as I screw the plug into the hole. Also be careful that you don’t pick up any of the grunge that may have accumulated over the years around the spark plug hole in the cylinder head on the new plugs’ electrodes/insulators/threads while you’re installing them – try your best to get the tip of the plug straight into the hole on the first shot.

For OEM parts at great prices, contact Chris May at Superior Chevrolet (1-800-728-8267), and tell him you're a Corvette Forum member.

Be well,

SJW

 

Removing the spark plugs and replacing with new is something I would do. Leaving spark plugs in aluminum heads for extended periods (10 years qualifies) is not a good idea. Many aluminum heads have been damaged when spark plugs were removed, the aluminum threads come out with the steel spark plugs. A bad day indeed. Make no mistake, I do not enjoy replacing C4 spark plugs. If I remove and inspect plugs at 30,000 miles, new ones go in, following the factory service manual instructions, and anti-sieze compound.

With less than 50K on the plug wires, ah, tougher call for me. If there is no indication of secondary ignition miss, wires look and feel good, resistance within spec, I'd change the plugs and go play golf. If you want a project that will have to be done at some point, follow the excellent post above and have at it. The factory wires is what I would use on stock engines.

Sounds like you have a nice ride.

Enjoy.

dlmeyers 90 coupe zf6 3speed shocks

 

Here's a little tip for you. When you buy new plugs get about a foot of rubber fuel line..I forget the size, but you want it to fit snug on the end of the plug, I have 2 pieces...4 and 5 inches long, I use them to screw in the new plugs by hand,then I use my wrench to snug them, thus eliminating the chance of cross threading the steel plugs into your aluminum heads. Been alot of guys here that have had to have their heads heli coiled because they cross threaded.