Hey guys I'm putting in a distributor with breaker points on my 76' cj-7. My old computer was fried so I decided to go with one with breaker points to make a simpler system. (might have been a bad idea?!) I just can't to seem to get it timed right. I got it started the other day but it took multiple times to start and it ran rough. It also would not idle with out me gassing it. Any tips on how to set one up? Thanks!
Prestolite ignition module isn't exactly a 'Computer', and it's not what I'd like to call 'Reliable' either.
For the price of a factory remain distributor, cap, rotor, plug wires and a $20 GM style HEI module you could have gone with a much more 'Reliable' ignition that would start fine when the weather is cold, damp, ect.
I would have got rid of the 'Prestolite' distributor/ignition module and went with something more reliable and higher powered, but to each their own.
Breaker points have a TON of issues, not many of them you can do anything about...
If you change your mind, look for ignition upgrades in my signature line for your specific year model.
Find COMPRESSION STROKE.
You MUST find compression stroke for #1 cylinder, or this is NOT going to work... PERIOD.
Once you find compression stroke underway,
Then you use a soda straw, chop stick, something SOFT that won't booger up the plug threads or piston head if it gets pinned...
BY HAND, turn he engine so you find the piston of #1 a top dead center with the 'Stick' you are using to feel for the piston coming up when you turn the crank.
Locate that piston a close as you can to 'Top Dead Center'....
Then, AND ONLY THEN, do you look at the balancer.
The 'Hash' mark on the balancer *Should* be very near the 'Zero' degree mark on the timing scale on the front of the engine.
If it's NOT,
The balancer is shot and you need a new one before you proceed.
If you have VERIFIED,
Compression Stroke on #1 cylinder,
TDC of #1 piston,
And balancer Hash mark on timing scale,
Then, AND ONLY THEN, do you move to the distributor.
You mark the #1 plug tower location on the distributor base circle, so you can see EXACTLY where #1 plug wire is supposed to be when the cap is off the distributor.
Then you flip the cap, see if the rotor is pointing at the #1 mark you made.
If it's not, then lift the distributor off the camshaft gear and try again.
The distributor may not want to seat on the engine/timing cover because of the oil pump drive, so you have to be aware of that and deal with it.
You 'Can' try to use a screwdriver to locate the oil pump shaft,
But if you can turn the engine freely,
You CAN turn the engine TWO COMPLETE REVOLUTIONS, and come back to having the 'Hash' mark back at 'Zero'.
The distributor will drop into the engine in the first half turn of the crank, but my MUST do two complete crankshaft revolutions and come back to zero to have TDC of Compression stroke again.
The cam/distributor turn at HALF SPEED of the crank, so it takes TWO revolutions to come back to COMPRESSION stroke.
And this might take three or four tries to get the distributor to engage the camshaft gear at the correct location, since the teeth on the gear are spiral, you won't wind up where you think you are going to as the distributor drops and engages the camshaft gear.
You have to back the rotor up (counter clock wise) a little to get the correct tooth engagement for the rotor to come back to the mark you made for #1 when it fully drops...
Once you get the distributor FULLY SEATED on the engine/front cover,
And the rotor lines up with #1 mark you made,
Then this is the 'Easy' part,
You turn the crank BACKWARDS until the 'Hash' mark is at the 6 degree advanced mark on the timing scale.
It's only a SLIGHT movement.
Then you go back to the distributor.
Hook your test light to the battery positive terminal,
Probe the wire from the breaker points distributor while turning the distributor SLIGHTLY...
If you turn the distributor housing enough the rotor is no longer pointing (more or less) at the mark you made, you went too far...
The EXACT second the light goes out, you are timed close enough to start the engine.
Clamp the distributor down, put the cap on and install the plug wires to their correct locations.
When you get good at this, you won't need a timing light, but for now, use one...
Put the cap, wires on,
Hook the distributor wire to the NEGATIVE side of the coil, and you are ready to start the engine.
Don't forget to clamp the distributor down before you crank the engine...
You can start you firing order on the cap anywhere you want to, just go clockwise from which tower you select as #1.
Depends on the engine, you haven't told us I-6 or V-8 yet...
If it's a V-8, most Delco distributors designate the plug tower just before the vacuum advance (clockwise rotation) as #1,
On the I-6 engines, it's kind of overlapping the vacuum advance a little.
On the later Motorcraft electronic distributors, the designated factory #1 is the first terminal PAST the vacuum advance (Clockwise) but still right over the vacuum advance linkage where it hooks to the distributor advance linkage...
Here is an I-6 Motorcraft distributor pointing at 'Factory' #1 plug tower location,
Now, if this were a Delco factory install,
The top picture, the #1 terminal would be one to the RIGHT of where it is shown...
And the vacuum advance would be pointed out away from the engine a little more.
This might help some, Factory verson of firing order diagram,
New points gap at a slightly different setting than used points is the reason I asked
I haven't touched the points on the new distributor yet.
I am still running the old coil but I was told that it would work? The canister coils are stamped "for use with points ignition" or "for electronic". If it were me, I would use the proper one. Honestly, I do not know what the difference would be other than internal resistences.
The electronic ignition Jeephammer is urging you to swap in, is the way to go in my opinion, but with that said, I always keep a points distributor nearby for emergencies. Usually it is someone elses Jeep that needs one, because I run the duraspark electronic with a TFI coil. The large cap and rotor with cap adapter etc...
I personally swear by it, but other on here like the simplicity of a GM style HEI. The one wire hookup etc...
I have a very hard time getting the cheaper brands to work well due to the advance curve being setup for a SBC. For around $75, you can do the cap upgrade to a $50 distributor, and know you will have an ignition sytem that is made up of easy to find parts, and is every bit as good as an HEI.
I have tried both, and I don't see much difference other than the price and the previously mentioned tuneability issue I have seen.
'85 CJ7, BDS 4" lift, 1" Body lift, 33x12.5, Shrockworks Sliders, 304 V8 with RV cam., T-176, D300, Dana 30, AMC 20. 1986 CJ10-A SD-33 Diesel/727/np208 1971 800B with 345/T-19
06' TJ Rubicon, 4" R.C. springs, BFG/AT 35s M.C. 6" fenders, rockers and surrounds, Currie front & rear adj. tracbars, tattons DC rear shaft, adj. upper - lower CA's. Bilstein 5100's YJ Buggy Build Current project. Stroker/FI ?
1990 MJ Comanche 4.0L AX15/np231
For the time/money it's hard to beat a $50 reman Jeep/Motorcraft distributor and $20 GM style HEI module, reasonable coil...
Cap, rotor, plug wires are a wash, since you have to change those 'Tune Up' parts anyway from time to time...
There is some wiring, but it's a good solid ignition giving you the best of all the 'Factory' parts you can get 'Off The Shelf' at any parts store for cheap...
And since it's modular, if anything better comes along in the future
You can change/upgrade any part of that particular system...
(say, PLASMA discharge via a 'Flux Capacitor' in the 1.3 Gigawatt range or whatever )
It's just a good, solid, hard working ignition all the way around,
And you can 'Trick' it out with a CDI module, pressurized cap so you can run underwater, ect. with little or no effort.
You don't have to worry about gear install heights from "China" made distributor housings,
Hardened 'Import' gears, or any of the other problems the cheap offerings have,
Or throwing out $300 to $500 for a distributor that won't perform any better than the $50 unit off the shelf at 'Auto Jerks' in your own neighborhood...
No dinking with proprietary crap from aftermarket suppliers every time you want to tune it up or have a failure someplace, you just get a replacement from the local 'Auto Jerks' and get back to wheeling.
Some 'Points' coils have built in resistor (internally resisted) and others need an external ignition resistor.
Since he's got a coil from Prestolite unit, it will work OK, just needs to add an ignition resistor.
If you are wondering why the resistor, In the old days, they were called 'Points Savers' instead of resistors.
Resistor goes in line before the coil between coil and normal coil supply wire.
Start with about 1.5 Ohms or 1.8 Ohms, that will usually keep the breaker points alive for a while...
IF the 'Condenser' (Capacitor) isn't working, the breaker points won't live long either,
But since this is a fresh rebuild, I'm sure the capacitor was tested before it left the factory.
Point gap is the big deal when you first start up, You need enough point gap to get it started, usually around 0.020" at fully open,
Then once you start, set the point gap with a dwell meter.
NEW distributors usually work pretty good with the factory recommended breaker point gap,
But if the distributor has much wear on it at all, you need to use a dwell meter to set dwell angle dynamically instead of relying on point gap from a worn distributor shaft cam lobe set...
These guys around here blasted the crap out of me for saying you MUST have a dwell meter if you intend to set breaker points correctly, that everything works perfectly with gap opening settings...
Well, they have no idea how a distributor wears if they think that...
DWELL is how long the breaker points stay open in crank degrees, so around 28-32 degrees dwell is what you are looking for during operation.
IF you set the breaker point gap and walk away,
Shaft/bushing wear lets the shaft move closer to the breaker points,
That opens up the gap and increases dwell.
If the shaft moves further away from the points, that Decreases dwell and closes up that gap,
If the tops of the cam lobes that open and close the points wear, that decreases dwell.
If you pay attention to the gap opening ONLY, and the lobes wear,
You can actually have breaker points that stay open all the time, or stay open way too long,
And the coil can't saturate for the next cylinder in the firing order.
As the lobes wear, there is less distance between 'Fully Open' and 'Fully Closed',
And if they wear enough the dwell will be way too long, the next cylinder won't get near enough spark energy,
If it wears a little more then the breaker points never close, they go from the 0.020" or so to 0.003" then back open, and the engine won't run at all...
You still have the 0.020" or what ever the opening specification is,
But the breaker points never close, or don't close long enough for the next cylinder to get a full spark energy discharge when it's time.
It's always a pain in the butt when the guys that did things wrong for years want to argue with the guy that knows what's going on, worked on all this stuff dynamically, understands how all the parts fit together, what they do when they move...
I COULD NOT drill it into their heads that shaft wear, lobe wear, ect. all effected the DWELL, the dynamic operation of the ignition systems,
It was point gap and that's it for them, and they would NOT read anything posted, or it would have become crystal clear...
(you can't fix stupid...)
You CAN get an engine running by setting the point gap,
Some run fairly well when everything is new and tight by just setting the point gap.
But you MUST have a Dwell meter to get it running correctly, and keep track of the wear/issues in the distributor as time goes by...
And if you don't have a plan to test the 'Condenser' when you tune up, then you are pissing in the wind.
A failed 'Condenser' will kill a set of breaker points in no time, and they DO come FAILED out of the box...
So you have to test...
I've seen more than my share of "Won't Stay Running" or "Won't Run When I Try To Accelerate" complaints,
Everyone goes DIRECTLY to the accelerator pump in the carb or to vacuum advance in the distributor...
The first question I ask is,
"IS it blowing down through the pipes when it gives up, Or is it popping backwards through the carb?"
Here is the rub...
Blowing backwards through carb, LEAN MISFIRE. Accelerator pump issues.
Blowing down though the pipes, UN-BURNED FUEL getting into pipes, Ignition Issue...
Late fire or no fire at all...
Then there are the Vacuum advance haters...
If the vacuum advance IS NOT working, then there is ZERO vacuum advance when you try to accelerate.
If the vacuum advance IS working, vacuum drops when you open the throttle blades, there is ZERO vacuum advance when you try and leave the line...
They DO NOT know how it works, so they blame the vacuum advance, when the vacuum advance has NOTHING to do with acceleration...
So when they bring vacuum advance up, I already know they have NO IDEA what they are talking about, and I start from scratch to find out what's happening...
Up, lean misfire,
Down, Late ignition.
So I have a look at the breaker points...
BRAND NEW, PERFECTLY GAPED to factory specifications...
Ask what the dwell was when they put the new points in and get the blank look and open mouth.
Hook up the dwell meter, reasonable dwell at idle, around 30 degrees or so,
Hit the throttle, DROPS TO 12... NOTHING WILL RUN AT 12 DEGREES DWELL!
Grab the rotor and wobble the shaft, moves around like screwdriver dropped into a pop bottle!
Virtually NO bushings at all.
These 'Experts' had been running straight 70 weight aircraft oil in a Ford engine with high volume pump & hex drive pump to distributor connection and it simply wore the bushings out in the 'New' distributor out in less than two weeks...
And all of them standing there SWEARING that electronic ignitions without breaker point were the 'Devil',
And you didn't need a dwell meter EVER to tune a breaker point ignition...
You can't fix stupid...
And that same deal his repeated it's self over and over again down through the years,
With Jeep distributors, it's simple wear on the bushings/cam lobes from use,
They don't use a hex drive, so some of the stress from the oil pump is relieved by the Tab/Tang arrangement for the oil pump drive,
But there are plenty of worn out bushings and cam lobes out there...
The re-mans often come back with used advance heads/cam lobes, so you MUST have a dwell meter to get them properly adjusted.
You CAN NOT make a guy pull the rotor and oil the felt pad in the advance head under the rotor when he does an oil change, (and that goes for all Jeep/Motorcraft distributors also! Electronic distributors need lubrication too!)
You CAN NOT make a guy put dielectric grease on the cam lobes when he does an oil change or tune up,
They usually install the breaker points DRY, so the cam lobes NEVER see lubrication from day one...
You CAN NOT convince guys to file the breaker points every 1,000 miles or so, so the breaker point faces stay flat and square with each other and conduct the MAXIMUM amount of current through the coil when they are closed,
And you CAN NOT get guys to use a dwell meter when the file the points, and reset the dwell after making that change in clearance with the file...
Breaker points take a LOT of maintenance and some specialized tools, like proper ROUND (Wire) feeler gauges for breaker points,
Proper breaker point files so the points turn out the way they are supposed to,
And they will not buy a dwell meter to keep up on the health of the distributor, keep it tuned.
The BEST you are going to do with breaker points is 15,000 to 20,000 volts, which is BARELY enough to ionize the plug gap on a nice day,
And if you figure in a cold engine, cold coil, low voltage from the battery because it's cold, and some moisture in the air that makes condensation in the cylinders,
You ARE going to have mornings the vehicle simply won't start unless you use some starting fluid and dry things out/heat things up so that under powered ignition can do it's job...
I'm old enough to remember the days when it took two or three hours to get the vehicle running when it was cold, and it was 'Standard' everyone had those days...
There is a reason NO ONE uses a breaker point ignition anymore from the factory,
If it worked, we'd still be using them since the factories could make them MUCH cheaper than they can the higher powered electronic ignitions that will throw 35,000 to 45,000 volts all day long, with MUCH longer spark duration in the plug gap and MUCH increased Amperage in that spark at the plug to get things started.
NO messing with 'Friction' surfaces that wear out.
The gap between 'Reluctor' and 'Stator' (Trigger) in an electronic ignition can be 0.065" with no issues what so ever and no problems with shaft wear what so ever.
If you didn't 'Tune Up' breaker points every 1,000 miles, and/or replace the breaker points every 3,000 Miles, you were risking being left on the road side...
Now we have distributors that do 250,000 miles without ANY SERVICE what so ever...
(That doesn't cover cap & rotors, just the distributor trigger/advance hardware)
There are only 4 parts that can fail on an electronic ignition,
Stator (Trigger) in the distributor,
Wiring in between the three,
There are at least a half dozen things I can think of that can fail in a breaker points distributor besides the listed above stuff... and they do it REGULARLY...
These are YOUR vehicles, run what you want.
This is just a direct comparison, maintenance issues, ect between the two.
If you are more comfortable with a breaker point ignition, that's your business.
If you learn a little about electronic ignitions, and want to go that direction, that's your business.
If you want to run a high dollar aftermarket, proprietary ignition, that's your business.
I'll help you all, anyone and everyone, with what you want to run,
And I'll help you if you want to upgrade for a reasonable amount of money,
Or if you want to go full tilt at something.
It's not a scrap of difference to me, I've done about every combination you can think of hundreds of times, and I'm here to help...
I'm also here to educate, so don't take it personally if I prang on the features or pitfalls of the ignition you chose,
It's not personal...
Just comparing apples to apples and trying to get the 'Best Bang' for your dollars!
i had to change points so often on my karmann ghia, i could do it by the light of a cig lighter.
I JUST BLEW SNOT OUT MY NOSE!
Would have been good to know about the resistor and condenser thing back then! Might not have had to change points so often!
When I was young, and I mean VERY YOUNG, around 14 or so,
I converted a TON of VW distributors over to electronic triggers.
It was actually how I purchased a dirt bike that summer...
LOTS of bugs and buses around that summer, And SURPRISE, when I was done with them, they all started!
The VW guys were SO GRATEFUL to be rid of breaker points it wasn't funny!
If I'd had the internet back then, I might have made a business out of it instead of part time, word of mouth customers...
Every town had one,
The 'VW GUY' that always had several around,
And he would send his customers to me to get the conversion.
Used Chrysler modules back then, and they fired right up!
The other guys that were good money, but lousy customers were the MG and Triumph guys...
Did you know that Lucas built refrigerators and ignition systems?
That's why the English walk a lot and drink warm beer!