1976 CJ-5 question from Orygun

Hello everyone and thank you for all the valuable information!
I have had my jeep for about a year and I have learned more in one week reading here than the rest combined. I have a 1976 CJ-5 with a 304 and a three speed (T15 from what I gather). It is all stock except for a 22 GAL fueltank. Of coarse it has some bugs but overall it has been very dependable. The problem I am having now is I believe an ignition problem. When it first began it would happen when I went over a bump/railroad tracks. All at once everything would shut down. At first it seemed like a fuel problem but everything checked out.What is weird is as soon as it happens I can hit the clutch, turn the key and it starts right back up. I have tried popping the clutch but this wont work and usually creates a mellow backfire. I saw a post in here somewhere about a diamond shaped connector in the wiring harness that seemed to create a similar problem but where exactly should I be looking? It does have the prestlite distributor which leads me to my next question. I am on a very limited budget and looking at the distributor upgrades out there it seems the mototrcraft would be my cheapest fix for the time being. This might show my inexperience but what model ford or part number should I be looking for. Are all 8's the same? Any help would be appreciated.I promise shorter posts from now on.

 

greetings ! lots of possibilites here
the elec ignition system back then was Prestolite. Can be troublesome at times.
The first thing I would check is the wire harness connector at the dist; the factory connector was a 2 wire rubber molded plug; this plug was prone to corrosion and caused problems; the factory had a recall (IGWire) to cut out the connector, seperate the wires, resolder and install heat shrink tubing over the soldered ends. It's possible this has already been done to yours, but factory stock units are still out there. The main thing is you want good soldered leads at the distibutor.
Next is the plug at the elec ign control unit/box. Same thing here; prone to corrosion; I have seen some with so much green corrosion that it was almost impossible to clean it all off; I wouldn't reccomend cutting the plug, for if replacement unit is needed, makes replacement difficult; only cut the plug ends off as last resort! (maybe this has been done to yours already). All rubber plug connectors should have dielectric compound liberally applied to prtotect them from corrosion.
I would check all your ignition connections and engine grounds.
The pick up sensor /trigger wheel inside the dist can cause problems. The rivets on the pick up sensor can loosen up causing the trigger wheel to hit/damage the sensor; if so replacement is necc of both components. Worn dist bsuhings can cause the same thing. Remove the cap/rotor/dust shield to inspect these items. This condition can also cause lack of power and sluggishness.
I suppose the control unit can also be suspect; usually soft rubber hammer taps or vibration to the control unit might make it quit; engine heat in the compartment can affect it as well. Symptoms may include sudden shut off at any time for no reason; may also restart right away or after a few minutes.
Lots of other things as well; loose connector on ignition switch under dash; main harness connector at firewall loose or dirty.
Hope some of this helps and makes sense.

 

Thanks for the clues. I do still have the connector on the distributor so ill start with that first. fingers crossed!

 

I had a similar problem with corrosion at the firewall connector on my '74.
Starting after the initial start sounded like a weak battery or warped flywheel.
After inspecting the obvious connections, flywheel, trying high torque starters, high CCA batteries, alternator rebuilds, I started pulling connectors, and found one wobbly connection. It revealed one corroded connector in a firewall harness. I sprayed it w/WD40, scraped each side with a blade, bridged the connection w/a piece of stripped 16 Ga wire, reassembled, and it started perfectly until I replaced with my painless wiring kit.
I make a habit of spraying my wires & switches lightly w/WD40 once/2 mos. or so, more when my top is off & the wires are exposed to the elements.

gj

 

Why not try dielectric grease on the connectors? It will last so you don't have to spray the connections with wd that will evaporate. Just a thoght

 

Hello again, I tried the dialectric grease today. I put it on every connector I could find. Ran the Jeep around the block a couple times and to the store and nothing yet. It is kinda spuratic though so Im not getting too excited yet.Still I hope for the best. The harness on the engine compartment side looks like it has had some sort of goo put on it already. Not like the grease but more like a black tar substance. Thay all seemed tight though. Did anybody know about the distributor question? i.e which motorcraft dist? Dont know about where you all are from but around here wrecking yard guys aren't very helpful. Better know exactly what your looking for before you make the call. any help would be awesome. Jeff

 

Just received my HEI distributor yesterday. I won it on EBay and paid $168.00. Its off an early 80's GM product and, for the money. I believe its the best upgrade available. I will be installing it this weekend in a 75 CJ5 w/258. Should be a pretty easy swap.

The distributor I got is a Delco-Remy with the coil on top. Rotor and cap are in fine shape and the gear that engages with the 258 oil pump has been changed to fit correctly. Also came with a set of 8mm high energy plug wires made by Belden (good stuff). This unit only requires one wire...a 12 volt keyed by the ignition. Optional hook-up for tachometer is also included.

This set up completely replaces the Prestolite distributor/external coil and the ignition control module mounted on the firewall. The HEI provides a much greater voltage to the plugs and is pretty much maintenance-free. Plugs are gapped at .045-.055 so you get better performance and gas mileage. I'll keep you posted on results ...........

 

The Prestolite system was know for unexpectedly quitting. You'd drive for a while and the engine would just stop. After sitting for a while, the engine would start and run perfectly. May be related to under-hood temperature. Carry a spare control module if you stay with Prestolite.

If you want to replace the Prestolite system, I'd advise you go GM HEI (high energy ignition) instead of the Motorcraft system. After 1978 (?) Jeep switched from Prestolite to Motorcraft EI, though they went with the low-end configuration. This included a conventional coil, conventional distributor cap and conventional wires. The Motorcraft system can be upgraded to the high end system (usually called TFI; thick film integration for the type of coil it uses) - this is a popular change for Jeeps that already have the Motorcraft distributor.

The GM HEI distributor from a Chevy 230 or 250 cid inline 6 can be used in a 232/258 by changing the distributor gear. You can do this with junkyard parts, or there are several companies that sell the complete GM HEI distributor. The GM HEI is (arguably) more reliable than the Motorcraft system, is a "one wire" system, and comes with all the high-energy parts that you would have to upgrade the usual Jeep Motorcraft distributor to get.

Do a Google search - you'll get lots and lots of hits.

 

Thanks for the tip.

I'm not certain if they used Dilectric in '74, but with the highly acidic cedar/pine water, sometimes brackish water (the Delaware River is tidal for over 60 miles, the official salt line is said to be around my County, and the salt atmosphere down the shore here in the NJ Pinelands, and I assumes the extra engine compartment heat from currently running headers, it does not take long for dilectric to turn into a hard glob of "Insulator", then eventually crumble and FUBAR or fall out instead.

I've seen this happen on my Fords (Dilectric kings) and many other people's vehicles, with or without headers. Monster Mudders here despise dilectric (most run Fords).


I'm assuming that the Painless kit came with dilectric and since it's about 5 yrs. old, I will start seeing similar problems.

I don't run as much mud and water as I used to because I can't afford huge repairs on a fixed income, and we're currently bringing Jeep back up to snuff, but with the powerwashing inside & out every week & the above environmental isussues, I think a quick spray of kerosene (WD-40 - affectionately known as Wire Drier to we points ignition runners) helps even with dilectric.
re: Motorcraft electronic ignition - all original electronic ignitions were an experiment towards improvement for a few years. Every one of my Ford work trucks had a spare ignition module behind the seat (up to my final '85). This saved me a few carb fires, etc, from employees who were trying to diagnose.
Always start w/spark when diagnosing a Ford electronic ign. engine.
I carried an ignition eliminator, which was a small box that bypassed the existing ignition & hung under the hood & was designed for towmen/onsite auto repair calls. I ran it on a TR-7 for years instead of putting out $150.00+ for a module that could fail jump street.

gj

 

I'm guessing that you may have a good amount of pines in your area, but I've seen NJ Oceanic and Pinelands metallic corrosion studies, even with epoxy coatings, and rust never sleeps. I've found that WD-40 works for me. If I had a spray gun, I'd just siphon & filter my No 2 from my furnace & use that.

gj

 

There was a service bulletin from Jeep in 1975 re dielectric grease. They provided a kit with grease and instructions for useage on both the connector between the ECU and distributor, and under the reluctor coil in the distributor. As I recall, the reluctor coil is grounded to the distributor body, so you need to attend to any corrosion there too.

 

Yeah, I have found alot of info about V6 ignitions but what about V8's. Is there a nearly direct swap for motorcraft or GM?

 

To use a GM HEI, you need to machine the GM distributor housing and replace the gear. Zack at Z&M Jeeps sells a GM HEI that drops in to an AMC V8. http://www.zmjeeps.com/hei_8.php

I think there are others too.

The other alternative is Motorcraft Duraspark/TFI. A Wagoneer makes a good donor. You'll need the distributor, ECU, and wiring. Connecting the new harness to your old harness requires splicing a few wires, and you'll need to buy about $100 of new parts to upgrade the Jeep distributor to TFI.

<edit> There are lots of discussion of ignition systems for AMC V8s on the IFSJA board. Here's a recent post: http://www.ifsja.org/ubb/ultimatebb.php?ubb=get_topic;f=2;t=035628
Also, a '76 will have a Tremac T-150, not a Borg-Warner T-15. Just FYI.

 

Thanks timgr, I called today and the wrecking yard had a 1982? wagoneer with the whole system. Think they wanted $50.00. Its off a 360 but if I am understanding correctly they all interchange. They also had an intake as well which is cool but I still need a 4bbl carb. Thanks again. THIS SITE IS AWESOME!! I will post pics when I figure out how to resize them. Jeff