Parts Jeep Trail Build

I’ve taken the first step of a long journey towards bringing the jeep into the technological world of the 1980s by upgrading to a TBI system. First I needed to upgrade the distributor to the 1970s by removing the breaker points and condenser and installing a magnetic pick-up coil and reluctor. Disclaimer: this is all information I gleaned from Bill Hamilton’s work over on the Binder Planet site because I’m nowhere near smart enough to figure this out myself. I started by scoring some JY parts from a Ford truck with a stock Dura-Spark distributor. The Ford pick-up coil ended up being too big to fit under the cap of the Mercruiser distributor so I got a Mopar coil and reluctor, which are smaller and shown in the photo.

 Since the Mercruiser is a 4 cyl, I modified a V8 reluctor by removing every other fin and opened up the ID so it would slip over the breaker point lobes. I then wired up the distributor to the EFI ignition module, GM coil and a 12V battery with the distributor clamped in a vise. After some trial and error, I was able to spin the distributor shaft by hand and make sparks. I was so happy with this success that I did this many times- it’s fun!

Next, I want to reinstall the distributor in the engine and test fire it just to confirm it will run and also to see if the drivability issues are really the carburetor or just my antique ignition. If it still runs horrible, then I’ll forge ahead with the TBI plan. The mechanical advance will need to be disabled and the engine timed to 0° before moving forward w/EFI. The Mercruiser distributor doesn’t have vacuum advance at all so that is one less variable. Once connected up to the ECM, the computer will perform all ignition functions and the distributor will just be reduced to a trigger.

Last weekend was the Portland Swap Meet. I didn’t go in pursuit of jeep parts but I did find a rather nice low-number 1947 Oregon license plate. This plate is just for decoration (and to answer questions about what year the jeep is) and won’t be registered. My other jeep is registered this way, with an old plate, but there are limitations on how the vehicle can be used and I wanted to drive this jeep more than the vintage plate rules allow.  The DMV sent new 2021 stickers for the registered plates (which will probably expire before the jeep runs again).

I managed to get the ECM mounted in an out-of-the-way spot under the dash. Welding tabs under the cowl was only so much fun. It took a bit of courage, but I cut a 2 1/8” hole in the firewall for all the wires.

Now to deal with all of this- most of the wires will not be needed and discarded. I’m still looking for a good wiring diagram for an ’88 Suburban. I also reviewed the progress of this thread during the last twelve months and it’s dismal, I need to get in gear!