How about this ,
Get yourself a distributor cap , spacer and rotor for a 1982 Ford F150 4.9l inline six , you will need the wires too. A stock coil or an Accel high output coil will work too.
What this does is spreads the contacts within the cap out to a wider circle , reducing the possibility of cross fire.
This is what I did on my 88 ( for a while ) before converting to an MPI high output power train.
I spent a weekend doing the following........
Removing all of the pulse air crap and associated BS , vacuum operated "engine management" controls , the microprocessor , the carter feedback carb , and so on. Most of the time was spent un-doing the wiring harness , removing the wires that were part of the feedback / pulse air operating circuits and be-bundling it all so that the untrained eye would assume it's stock , nice and tidy.
Some splicing ( soldering & heatshrink ! ) will be necessary , it's not easy . Plenty of thought and planning went into what wires were needed , what was not and how to arrive at a simplified engine harness cleanly and professionally , the goal being reliability. The Ignition module ( below the washer bottle on the left inner fender ) , can be wired directly to the distributor , I built a sub harness for this using waterproof deutsh connectors. that took care of the ignition system. The charging system can remain as it is , I just cleaned mine up and re-bundled it. The starting system needs little work , going from memory , I had to make a proper ground for the starter relay , clean up some additional wires , sort out some crappy wires for the backup lighting and there were a few splices needed to finish up.
The Vacuum circuits become far more simple , I retained the purge canister , AGR valve , the CTO , the TAC / VAC for cold / warm up , switched the vacuum source to the distributor to a "ported signal " from above the throttle plate .The stock / microprocessor controlled system uses manifold vacuum to control timing , combined with signals from several sensors , including an oil pressure switch ?? , an O2 sensor , a manifold heater , the pulse air solenoids etc. , etc , far to complex ! compared to later vehicles. Hey , thats how they did it in the 80's ! :roll: . Some knowledge of automotive tuning is needed to pull this off sensibly. The timing will have to be adjusted , using a timing light and a Vacuum guage ( old school style ) , 10 degree's of base timing is a good starting point. Use all new vacuum hose ! , you may have to buy a couple of tee's . I went with an Accel coil ( I still have it & for sale ) , Oh , I should mention , the starter relay limits voltage to the coil by way of internal connections and some resistor wire in the circuits , it gets a full 12 volts while cranking and 6 volts when running , this is how these Jeeps are wired from the factory , take that into consideration when re-configuring the wiring.
I used a reman CJ carb (1981) , no stepper motor on that one and connected the electric choke .
Before this my Jeep would stall , was hard to start , would stumble and hesitate , the detonation was out of contol , fifth gear was useless and the engine would barely rev beyond 3000 :cry: . After , it would idle cleanly , start easily , had more power and would rev higher .
I have not used the Motorcraft 2100 carb but hear is far better than any of the Carter carbs AMC / Jeep used.
The HEI conversion is also said to be a vast improvement too.
Some additional reading
How 80's stuff works .....
http://home.sprynet.com/~dale02/list.htmA simple bypass ......
http://www.4x4wire.com/jeep/tech/electrical/jn-ignition99/What ever way you choose to go , think it through , be methodical in how it's done and good luck.
Ultimately , all of these old Jeeps are better off with a proper conversion to MPI , it's the best way to prevent stalling on steep or off camber terrain.
Topic: TFI vs. HEI Upgrades (Read 1397 times)