updated...TIMING COVER IS OFF ... SEE PICTURES..

Hello,

Some of you will remember my ongoing dilemma. My 1967 Mustang with a 200 six keeps going out of time. It is a rebuilt motor with about 10,000 miles on it. I can move the distributor and get it to run again. I have replaced basically everything that will unscrew or unbolt!

I'm 99.9% sure it is a timing issue...

I changed the distributor (reman load-0) and it made no difference. I can time the car + adjust points it will idle and run then timing moves and I'm screwed.

I pulled #1 spark plug, located compression stoke, confirmed rotor pointing at plug wire #1, then check that harmonic balancer showed TDC (close to it anyways). This is after a different distributor...

I'm going to pull the valve cover and look for anything suspect, then I guess pull the timing chain cover.


I guess it is the timing chain?
Would a stretched chain behave this way?

addo changed a timing chain on one of those strange little foreign cars he works on and it was stretched enough to change the timing significantly

It was a belt, but yes I was surprised that a difference was noticeable.

However, stuff more likely to compromise timing here, could be cam walk (unusual!) or something like distributor cap fitment or even dwell settings.

Are you able to borrow a "known good" non Load-o-Matic distributor from anyone? One problem with the LOM is it relies on a standard vacuum signal régime, from a motor in good health. If that side of the "supply" is not up to much, then results will suffer.

The car will change timing at start up. It will idle great with perfect timing and point gap then I shut it off. I go to start it and it is off time and will not run unless I move the distributor. It also will change timing if I get it all set and try to drive it. I make it a few blocks then timing changes and it won’t run at all.

It behaves exactly the same with a remanufactured distributor installed. By the way, there was nothing obviously wrong with the old distributor that I could see. I was really hoping a new distributor would fix it!

The distributor is not getting vacuum at idle right? The carb is an autolite 1100 with scv. The advance is working by the way.

Between this ordeal and a fried resistor wire I have changed all of the following in the last couple months…

Changed to a different carb, removed pertronix 1 and went back to points, new spark plugs, new coil, new rotor + cap, new plug wires, new fuel pump, new fuel filters, wiggled all wires while running, checked firing order, checked and re-checked point gap, Checked plug wire + coil wire spark, changed to rebuilt distributor + stared at engine and prayed!

I'm pretty sure it is timing because...the car will idle and run great then all of a sudden not...I turn the distributor and it will idle and run again for a while.

It’s looking like wrench through windshield time! :x

Certainly the symptoms you describe would generally go with a timing problem. Was there any wear apparent on the driven gear of your old distributor?

How many inches of manifold vacuum are you getting at idle? What about at 1000RPM? If you tee into the distributor vacuum line, what vacuum readings do you get in 500RPM steps up to 3000 (remember to have the handbrake firmly applied and stand to one side of the car while measuring)?

Is dwell measuring between 38° and 42°? What points gap are you running, and is the block-firewall ground strap fully intact?

addo":3q86buwt said:

Certainly the symptoms you describe would generally go with a timing problem. Was there any wear apparent on the driven gear of your old distributor?

How many inches of manifold vacuum are you getting at idle? What about at 1000RPM? If you tee into the distributor vacuum line, what vacuum readings do you get in 500RPM steps up to 3000 (remember to have the handbrake firmly applied and stand to one side of the car while measuring)?

Is dwell measuring between 38° and 42°? What points gap are you running, and is the block-firewall ground strap fully intact?

Click to expand...

Thanks for the help.

Q:Was there any wear apparent on the driven gear of your old distributor?

A: No, none. I actually don't think there was anything wrong with that distributor now that I have it out and the new one in.

Q: How many inches of manifold vacuum are you getting at idle? What about at 1000RPM? If you tee into the distributor vacuum line, what vacuum readings do you get in 500RPM steps up to 3000 (remember to have the handbrake firmly applied and stand to one side of the car while measuring)?

A: I am getting a good solid 19 inches of manifold vacuum at idle when car is properly adjusted and before it jumps time again (or whatever is happening). I have not teed into distributor vacuum line, but vaccum advance does work and worked with my old distributor

Q: Is dwell measuring between 38° and 42°?

A: I do not have a dwell meter. I have had many cars with points and never used a dwell meter. I'm sure I could get it to run with setting gap. I have checked it many times.

Q: What points gap are you running.

A: 25 ... Per shop manual

Q: is the block-firewall ground strap fully intact?

A: Yes, Checking all of the grounds was one of the first things I did. Should be in my list of things I have done above.

Any other ideas? I really don't want to take off the timing cover unless I need too. Sounds like a bad chain though right? or cam or valves I guess...yikes

Here is the "kicker"...what would make a car do this?

Q: Car is timed perfectly (@ 12) , with correct point gap, showing 19 pounds of steady vacuum at manifold, fuel air mixture adjusted.

Shut off car...re-start car and car will not even idle until you loosen distributor and move it? Of course, eveything else is screwed up.

A: (you tell me)

My LTD did the same thing once for about two weeks. I was thinking that maybe it could have been a bad timing chain and gears, then it quit running completely one day. Found out it was the timing chain and gears.

bigfordsix":1oun9sjp said:

My LTD did the same thing once for about two weeks. I was thinking that maybe it could have been a bad timing chain and gears, then it quit running completely one day. Found out it was the timing chain and gears.

Click to expand...

I'm also thinking chain/gears

I would try unhooking the vacuum advance just to eliminate it as a problem source. An engine can run just fine on static timing up to about 2000 rpm or so (millions of tractors had no advance mechanism whatsoever). If the problem persists then it's time for surgery
Joe

Man,this thing is being a real pita. I feel bad about saying the dist is a 99.9% deal but from all the symptoms it is true. The chains get VERY loose but almost never slip a tooth,and when they do they do not go back where they belong.....they eventually just slip so far that valve timing is WAY off and the engine never starts again until a new chain/gears is installed. HMMM.
If you can get a wrench on the front crankshaft bolt you can wiggle the crank back and forth. Try to feel when the slack is taken up in the timing chain.....it is usually pretty evident. A decent chain will let the crank pulley move maybe 5* before the cam starts turning......a really loose one will be a lot more. You can also turn the crank with the dist cap off and watch the rotor to see how long it takes to move while turning the crank back and forth. A sloppy chain will really delay the rotor movement.
That's the best I can do.......

Terry

Have you checked to make sure the distributor housing isn't slipping? It's a longshot, but the distributor hold-down clamp may not be working right. Find a way to mark the distributor relative to the engine or fender. Run the engine to see if the distributor moves at all. It's worth trying since it's easy!

page62":10xju0xi said:

Have you checked to make sure the distributor housing isn't slipping? It's a longshot, but the distributor hold-down clamp may not be working right. Find a way to mark the distributor relative to the engine or fender. Run the engine to see if the distributor moves at all. It's worth trying since it's easy!

Click to expand...

+1

I still maintain that, if the timing chain were moving, it you would not be able to get it back to running right no matter what you did. The above mentioned test to check for slop in the chain is a good one... do that to eliminate the issue.

It is entirely possible that your timing+idle speed is just WAY off.

I like the idea someone else had for fixed timing, unhook the vacuum and try it running it. Performance is going to suck in certain areas but it should run fairly smooth. WHo knows maybe someone swapped the SCV with a power valve and the signal is totally wrong.

I also agree with the concept of a slipped chain, if it was that bad its not going to fix itself.

From what I've read, there are actualy two different dist hold down tabs. This would be for two different thickness dist bases.

I would tighten it up and try to turn it by hand. Then I would mark the dist base and block. Run it, and when it happens, see if the dist turns.

Bort62":iq9jj4n7 said:

page62":iq9jj4n7 said:

Have you checked to make sure the distributor housing isn't slipping? It's a longshot, but the distributor hold-down clamp may not be working right. Find a way to mark the distributor relative to the engine or fender. Run the engine to see if the distributor moves at all. It's worth trying since it's easy!

Click to expand...

+1

I still maintain that, if the timing chain were moving, it you would not be able to get it back to running right no matter what you did. The above mentioned test to check for slop in the chain is a good one... do that to eliminate the issue.

It is entirely possible that your timing+idle speed is just WAY off.

Click to expand...

Thanks for the help guys...

I don't think the timing+idle speed is just WAY off. I can get the car to idle with timing light + vacuum gauge hooked up. Car is timed perfectly (@ 12), with correct point gap, showing 19 pounds of steady vacuum at manifold, fuel air mixture adjusted.

Then shut it off and everything is messed up again.

Regarding unhooking the vacuum advance. That has no effect at idle right? At this point the car will not stay in tune long enough to drive it. Seems to be getting worse.

I will put a wrench on front crankshaft bolt and check the play as advised.

I will also make sure the distributor is not moving. I already have checked and re-checked that I could not move it by hand. Also keep in mind; the car is behaving exactly the same with 2 different distributors. I drove the old one for 7 years with no problems so it is likely not a hold down issue.

I would LOVE to have an ahhh haa moment and realize it is something simple!

At this point I don't care what it is I just want to know so I can fix it. It is killing my MOJO...and making me angry

bigfordsix":25n4dnx0 said:

My LTD did the same thing once for about two weeks. I was thinking that maybe it could have been a bad timing chain and gears, then it quit running completely one day. Found out it was the timing chain and gears.

Click to expand...

Could you get the car to run again by moving the distributor?

Sounds almost like the timing chain has stretched, and the chain can somehow rid up on the teeth then settle back down. Try to pick up a degree tape, or just measure out and mark the pulley so you can really make out the ariance in degrees of advance. Make a note of exactly how many degrees and in which direction the timing changes after you shut it down, and try to restart. In other words, does it consistently retard 5*-10*, or what.

If I were a betting man, I'd have to put my money on a stretched timing chain.

The only thing that has not been mentioned is the dizzy rotor........

The tab that holds it still might be striped and turning on the shaft or is the wrong one Or has a crack in it that opens up and turns (like using a cracked socket...

Nutz4mystang67":66h0mhfc said:

The only thing that has not been mentioned is the dizzy rotor........

The tab that holds it still might be striped and turning on the shaft or is the wrong one Or has a crack in it that opens up and turns (like using a cracked socket...

Click to expand...

Well...I just checked the rotor. It is new (like everything else!) and it is not cracked + fits right.

I just pulled the valve cover. Looks really clean and everything appears to be correct. Now I'm going to pull timing chain cover.

I hope the chain is streched or screwed up some how! Fingers crossed :roll: ...Sick of messing with this car...

Yes, moving the distributor one way or the other a few degrees would make it run better, still not really like it should have been running, but it was drivable, until I turned it off and restarted it. The day it quit, my wife had floored it at a stoplight and it finished off the cam gear. I then reinstalled a new adjustable timing gear set and it has run great since then.