I got my 1987 L98 running, but it is running poorly. I am guessing that a couple of spark plug wires are switched. The cap, rotor and plugs do not look that good either. Sooooo

Does anybody have a picture of the distributor wire positions?
What spark plugs are good for a normal grocery getter?
Any good or bad rotor and cap brands?

I think I will swap out the plugs, cap and rotor, check the wiring and see if I can not make the thing run right

Any suggestions

 

Everyone has their favorite and firm belief as to which is the best. Engine oil is even worst as all lubrication experts in the area being generally their garage.

Good or bad for cap and rotor is relative as in good for what use. For a street car for all the stuff listed that I would use, Delco or Standard Motor Products possibly Echlin. The color does not matter black is just fine and no sense in paying for red tan or some other one. The big deal is brass terminals and not paper thin. Wires gut feeling would be Delco nut I put a set on my '91 doing a tune up when I got it and the car ran worse than the originals to check put the originals back on and ran much better so called my buddies at Moroso's engineering dept. and told them what I wanted and they sent a universal V8 set and 1 odd wire. You can do the same at any speed shop or the usual discount mail order places. I like blue rather than black as black is made by using carbon that conducts electricity so not a style thing. You want 8mm spiral core with 780 to 800 ohms per foot. All the other stuff has it's place and that is not your car. Good RF/EMI and conducts easily is what you need. Mine have been on since 1/2009 and still work just fine for what is that is worth same for cap and rotor and it is a driver and goes in hot weather cold weather rain. A dusting or snow is no reason to park it just stay off the interstate or take off the wide tires with shallow tread.

There are a dozen or more brands of plugs. Personally I run Champion for a couple reasons years ago worked with engineering at their place on some projects, I understand their numbering system well and know what to ask for to get what I want. They have been dead reliable for me and the same ones in since 2009 and runs as now as it did then. AC plugs must be good at least in 2002 as I still have the same ones in my Pontiac sedan as new and has 93k miles on them great mileage and fires right up. No idea how good they are now though.

This is all my opinion and not looking to start a rake fight.

Oh firing order 1 8 4 3 6 5 7 2 It does not matter where #1 is as long as order is right and wires reach easily with fewest left right bank switches.

 

2 cents on this one -- asking what plugs and wires is like asking which wax is the best - most likely you will get a 1000 different answers. personally, I've been using NGK platinum without issues. as for the distributor cap, I tend to use ones with brass/copper inserts - usually accel cap and rotors, but my last purchase was an airtek/wells premium. seems to be a quality product - no issues. wires, taylor spiro pro, 8mm silicone. I've been using them for some 20 years now (about 4 or 5 sets installed on L98 motors), again without issues. they seem to fit very nicely with the factory routing, which leads me to my next point. for indexing the distributor, granted, it may not matter where #1 is as long as the wires are in then right order, BUT that delco HEI distributor was designed to be indexed in a certain position. the LH side of the distributor - the part where the coil, tach, and 12V connections are, SHOULD BE approximately 90° and perpendicular to the centerline of the engine (LH side). there is no "factory correct" exception to this positioning or indexing. any decent L98 wire set is designed to specific factory lengths and factory routing. the final installation will have the #1 distributor spark plug terminal, and rotor, pointing to the #1 sparkplug (approximately). as for the firing order, , 1-8-4-3-6-5-7-2.

search L98 plug wire lengths and routing - plenty of forum discussions on the subject.

 

If you replace the wires, watch how you route them. Assuming they are originals on the vehicle, the routing is usually done for a reason, including if they cross or not. If wires on two consecutive cylinders are parallel, you can have inductive firing in some cases. Most can be made prettier by rerouting but you can intoduce new issues by doing so. Route them as they were originally installed if at all possible.

 

Yes 5 and 7 need to be crossed pretty or not.