Older electronic ignition upgrade

[scramble96]

So I bought an '87 GW with Howell efi and a more modern style electronic ignition. The ignition system is like that of a late 80's to early 90's gm with no vacuum advance. The efi and ignition were installed over 20 years ago and I don't have any paperwork from the previous owner. It's time for a tune up. I need to replace plugs and wires. Does anyone have any suggestions?

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[Yeller]

For plugs, whatever the factory called for. For wires, a set for an 80’s GM v8 should work, but so will early 90’s ford. It would all depend on what angle of boot you need for your amc engine.

[tgreese]

Show us what kind of distributor you have. Different distributors have different plug wire and coil connector types, as well as the angle of the plug connector. Howell EFI is a fuel-only package, and has no control over spark advance. You should have some type of vacuum advance diaphragm with the Howell package.

[Yeller]

There are TBI systems that do control timing, lots of options with that system, made by lots of companies. They all use the GM computers and engine mapping. Some had timing control and some did not, just depends on the options selected. I’ve built several that used the HEI distributor from the 80’s with electronic timing control. I haven’t built a TBI system since about 2002, so I’ve forgotten a lot of what I knew and I purged all of my schematics, notes, and spare parts when I moved in 2019. Now I just order up the harness, have the computer unlocked and connect it up, been doing that for the last 20+ years.

[tgreese]

Not to belabor this, but the OP says it's Howell. Howell is fuel-only, and has no option for spark control. I own a Howell system.

The OP also says the ignition is like GM, which implies HEI? This would have posts on the cap rather than cups. Not clear whether the system it resembles has no vacuum advance, or this Jeep has no vacuum advance.