distributor hold-down prevents timing adjustment?

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73goldduster

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ok, the slant has been running a little rough, so i decided to check the timing. the underhood info says that it should be at 0*, which i think is odd, but whatever. when i checked, the mark on the damper was to the RIGHT of the mark on the block. when i loosened the hold-down bolt, i found that the distributor would only rotate clockwise, bringing the mark further to the RIGHT.

there's a slot in the hold-down that only lets the distributor advance so far. i want to advance the timing to the point where the two marks line up, right? when i blipped the throttle, the timing mark jumped to the LEFT of the block mark. she runs smooth at higher rpms, but kinda stumbly at idle. idle rpm IS a little low, 650.

do i have to re-clock my distributor, or is there an easier way to do this? i feel like i'm missing something here.
and yes, the pickup was on the #1 cylinder. (front of engine)
 
I might be wrong but I think on the underside of the plate with the slot is a bolt attaching it to the distrubutor, if loosened you can get a little more rotate on the plate.
 
you can always back all the plug wires one hole in the cap whichever way you need to give you full adjustment. Maybe someone put new wires on it and started one hole off. simple fix.Gotta think outside the box.
 
kokuda is right. There is another bolt on the bottom of the distributor that will give you more adjustment. Problem is that you may have to pull the distro to get to it or I have successfully used a crowsfoot wrench to get at it. It is almost 180 from the top bolt and is the same size, 7/16.

If you can't get enough there then you have to start moving spark plug wires and working from there as goldduster said.
 
There is a slant-6-specific distributor wrench, 7/16", that makes it easy to get to the other bolt on the underside of the distributor to get the adjustment range you need. It's a Vim #V103, available here for sixteen very worth-it bucks (or from a bunch of other places). The 0° (TDC) setting can be fudged a little for better driveability and economy; try 5° BTDC and keep an ear open for pinging.
 
Apologies for reviving an old thread.... I'm having the same problem, thinking I could reach the second bolt with the oil filter out of the way. Engine off, pull filter, make small adjustment, replace filter then with engine running set time using the primary bolt? Thoughts?
 
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distel said:
Apologies for reviving an old thread.... I'm having the same problem, thinking I could reach the second bolt with the oil filter out of the way. Engine off, pull filter, make small adjustment, replace filter then with engine running set time using the primary bolt? Thoughts?
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Why not just buy the right tool?
 
slantsixdan said:
Easier to just pull the distributor and flip it over to access the 2nd bolt, then.
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I've never pulled a dizzy before, worried that'll screw something up. Is it as straightforward as it sounds, just remove the bolt and slide it out, adjust the 2nd bolt or turn it one tooth and reinsert then bolt down at set time?
 
Adjust the slot/bolt. Turn one tooth will be too much unless the actual problem is the distributor is installed one tooth off now.

To remove the distributor on a Slant motor, remove the distributor cap, rotate the engine (by bumping the starter or pulling the fan belt and fan) until the distributor rotor points somewhere memorable: straight up, straight forward, straight down, straight backward. Remove the coil-to-distributor wire, remove the hold-down bolt, and pull the distributor straight out. Watch how the rotor turns about 20 degrees counterclockwise.

Adjust the hold-up bolt (holds the plate up to the distributor), making sure to move it the right way. Always visualize: rotating the rightside-up distributor body counter-clockwise in relation to either bolt hole on the hold down plate will advance the timing. Clockwise will retard. Before you actually loosen the hold-up bolt, hold the distributor upright and correctly visualise which direction you need the hold-down slot to move. Take your time and don't get crossed up when you turn the distributor upside down to do the actual adjustment.

Take the opportunity to have a look at the distributor drive pinion while it's out. If it's cracked or broken or otherwise alarming (chewed, falling off, etc), time to replace it.

There are supposed to be two O-rings on the Slant distributor. One skinny one in a groove in the distributor shank, and one fatter one right where the dist body meets the block. Missing either of these = oil leaks.

To reinstall the distributor, line it up with the block hole, spin the rotor right back to where it was in step one before you loosened the hold-down bolt, then rotate it about 20 degrees counterclockwise from there, and push the distributor home. When the distributor seats on the block, the rotor should be pointing the direction you originally picked in step one. Install the hold-down bolt loosely, attach the coil wire, install the cap, start the engine, adjust the timing correctly (distributor vacuum advance hose disconnected and plugged at the distributor end, engine idling about 700 rpm). Tighten the hold-down, unplug and reattach the vacuum advance hose.
 
Whatever timing you add at idle, will change all your timing including your power-timing.
So you will need to keep a close ear on the look-out for detonation.
IMO a rough idle needs a basic diagnoses.
I would start with a compression test and plug check.
 
HEAT UP a cheap wrench and bend it. You can do this with (in a pinch) vise grips or pliers and a propane torch

In my (old age) I've got wrenches that were bent, re-bent, cut and welded to a different angle, and "grinded on" to reduce the cheek size. One 1/2 inch I used to have was done specifically for some tight clearance carb mounting nuts, years ago
 
Also check the cam timing , the chain may be stretched . Thus retarding the timing and causing a rough idle.

Remove the distributor cap and watch the rotor as you move the crankshaft clockwise until the rotor starts to move then rotate the crank counter clock wise and note how far it moves before the rotor starts to move again. If you have more then 5* its time for a new chain.
 
I chickened out and took it into a shop this morning. I'll report back with the diagnosis. Thanks for everyones advice and time.
 
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Timing at 0 deg BTDC sounds a bit weak. Might have been for emissions in a later slant. I would start w/ 5 deg BTDC. If idling lean, it would like even more advance. The main disadvantage of too much initial timing is that when it fires before TDC, it fights the starter when cranking. With computer spark control (engines since ~1995), it can fire at TDC (or later) when cranking, then switch to what works good at 600 rpm idle.

Note that the gear teeth are slanted, so as you lower the distributor the rotor turns a bit, so allow windage for that. I never had to adjust the lower bolt on a slant distributor. Maybe I should have, but I always got one into adjustment range by rotating the rotor one tooth. I don't think I even knew the bottom bolt had an adjustment slot back then.
 
67Dart273 said:
HEAT UP a cheap wrench and bend it. You can do this with (in a pinch) vise grips or pliers and a propane torch

In my (old age) I've got wrenches that were bent, re-bent, cut and welded to a different angle, and "grinded on" to reduce the cheek size. One 1/2 inch I used to have was done specifically for some tight clearance carb mounting nuts, years ago
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I had a drawer full of those at one time.
 
I ended up taking her into the shop, mechanic said all that he did was "dead time" the timing. Found tdc, put a new timing mark and locked down the distributor. Runs good now, I checked the timing with my light and it is at about 0 degrees. Dunno what exactly I was doing wrong but maybe the timing mark I was using was wrong?
 
distel said:
I ended up taking her into the shop, mechanic said all that he did was "dead time" the timing. Found tdc, put a new timing mark and locked down the distributor. Runs good now, I checked the timing with my light and it is at about 0 degrees. Dunno what exactly I was doing wrong but maybe the timing mark I was using was wrong?
Click to expand...

Better learn to do this yourself or youll have empty pocket book syndrome letting a shop do it. Old cars will require love from you to keep in tip top running shape once in a while.

Get engine to tdc on cyl 1 by lining up crank mark with 0* on timing tab. pull distributor cap and verify rotor is pointed at 1, if at 6 go around again. ( Should be about 5:00) take a phone pic if need be of your current rotor position. Take hold down bolt out pull distributor, see what one tooth forward looks like, one back two etc,. Get comfortable with it, compare your new spot with your pic. Set it to 1 tooth advanced, ccw rotation of rotor (runs in cw direction) . Put back together. Done. Start and adjust timing.

I know dan and others ran you through it, but its just that easy, as long as cyl 1 is on tdc with rotor close to 4:00- 5:00ish its pretty fail safe.
 
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The outer ring on the crank pulley is a damper ring for internal crank vibrations; that outer ring is held onto the hub with a thin layer of rubber (which provides the damping). That rubber can get old and crack and let the outer ring slip, which moves the timing mark off of where it should be.

Eventually, that rubber may fail and let the outer pulley ring come off... or fly off. So if the new mark is some degrees away from the old one, then it may be time to start thinking about a pulley/damper replacement. That requires specific puller types for both removal and installation.

And it could be that you just did not find the right mark to use before.

Refer back to post #14; that is correct about the timing chain wear and retarded timing; the timing retard can be adjusted out for ignition timing by moving the distributor, but the cam timing cannot be adjusted out. Retarded cam timing of 5* will make the performance quite sluggish compared to what it should be.
 
nm9stheham said:
... Retarded cam timing of 5* will make the performance quite sluggish compared to what it should be.
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Depends on what "performance" means. I had a friend who used to drag race his Ford Pinto. Before racing, he would move the camshaft sprocket 1 tooth back on the rubber belt (OHC) for better high rpm performance (and thus max HP). He would move it back for daily driving. Similarly, many camshafts can be installed 4 deg advanced, 4 deg retarded, or "straight-up". Advanced is best for low-end and better mileage, while retarded is best for racing (but crappier idle). So, don't fret about a worn timing chain, since some people prefer the camshaft timing being retarded. BTW, I installed the new camshaft 4 deg advanced in my 273 engine since I prefer mileage and that also allows for future wear.
 
What I mean is that low and mid-RPM throttle response will be degraded.... as you say, the result of less low end torque with the retarded cam timing. For most daily uses for the /6, restoring the cam timing to as-new will make the engine a lot better to drive.

I replaced a worn /6 timing chain that was allowing 4-5 degrees of retarded cam timing and the result was as said: much improved low and mid RPM throttle response. So I'll disagree with the idea of not replacing a worn chain .... for most drivers, it will be a very noticeable and worthwhile improvement.
 
The lower adjustment was factory sey, not supposed to move it. How long would it have taken to just shift the plug wires? About as long as it took to write this. EDIS sets to 10 btdc so it can limp home with no crank signal. Won't be fun but it'll get you home.
 
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