Timing Issue

[Anonymous]

I have a 66 Falcon with a 200 matched to a C4 automatic transmission. My problem is that I can never seem to keep the car running right. Today I found out what a big problem might be. The car will not stay timed. I timed the car the other day when it barely had enough power to pull out of the garage, and I found out that the timing was over the top timing mark completely. I set the timing to 12 degrees T.D.C. which made a huge improvement. I went out today to take the car out and again it wasn't running very well. Upon checking the timing I came to find out that it had again slipped over the top of the timing marks (above 14 degrees T.D.C.)

I am hoping that someone will be able to tell me why the car will not stay in time. It has the 1 bbl autolite 1100 carb with the load-o-matic dizzy on it. When I set the timing the car runs very well, but unfortunately it will not stay in time for very long whatsoever.

Thank you for your help.

 

[addo]

It may sound silly, but check that the rollpin holding your distributor driven gear to the shaft, has not sheared through. You'll need to pull the unit out to inspect this.

Cheers, Adam.

 

[HighVolkage]

this may also sound stupid but are you sure your hold down is actually working properly?

 

[66 Fastback]

Your distributor bushings could be worn such that it will not hold time properly. A few years ago I had a motorcycle with a worn out distributor. I'd set the points gap and timing and drive for a while and the engine would start running poorly. Check the gap down the road, and things had changed. Make sure your points are tight and properly gapped. It could be that the points gap is moving which will affect the timing. If the points are tightened down, then it could be play in the bushing and shaft that is affecting the timing.

Another thing to check is to see if the timing mark on the balancer ring has slipped or moved. However, it sounds like when you set the timing back to spec it runs OK. A slipped balancer is not going to affect the timing if it moves more, unless the reference point for timing is not in the correct position. Anyway, pull the #1 cyl and bring the piston up to TDC by hand on the compression stroke. A long screwdriver can be stuck into the spark plug hole and watch the movement the screwdriver. If the balancer has not slipped, then at TDC all the planets should be aligned. Pull the distributor cap and the rotor should be pointing to the #1 post on the cap, the balancer mark should be at 0 deg TDC, and the screwdriver and piston should be at the top of its travel.
Doug

 

[fordconvert]

Are you using the correct procedure for setting the timing? A 66 could be a Load O couldnt it? Isnt there a differnt procedure for setting the base timing on those? I never messed with mine before I did the DS2 and dont have my book handy. Even if its not a Load O check the operation of the vac modulator and make sure its working properly and not binding. I have made the mistake of setting the timing with the vac hooked up before and spend many hours scratching my head trying to figure out why it wasnt working right. Also the hold down not clamping tight can mess things up as can loose bushings making the dwell mushey.

 

[Anonymous]

I went back through everything and made sure that my dwell and point gap were correct, and then i reset the timing. So far the car is holding time, but i have yet to drive it.

The problem now seems to be the car's performance. I have the dwell set between 38-39 degrees, the point gap at .025, the idle set at 500 rpm, and the timing at 12 degrees T.D.C. ...however, the when you put the car into drive, the idle becomes very rough. In park or neutral the idle smooths out and the car seems to be running fine.

I set the dwell and timing with the vacuum taken off the distributor. I also set the idle rpm in drive.

I have played with the fuel mixture screw, but cannot smooth the idle out.

Is this a common problem? I am I doing something wrong, or is there something that I can easily fix? The car again is a 66 Falcon with a 200\C4 combo. It does have the load-o-matic distributor.

I appreciate any help, advice, or criticism. Thank you.

 

[66 Fastback]

Idle speed specifications for automatic transmission cars normally call for the car to be in drive when the idle speed is set. The car should be warmed up and then have someone put it in drive while you set the curb idle speed. My car is not an automatic, but in park, the engine will probably idle around 700 rpm.
Doug

 

[fordconvert]

When you mess with the idle mixture screw can you make it worse by turning it 1 turn or less in either direction? If thats not how it responds you still have a carb problem or vac leak. My carb did respond that way so I tore the engine down and didnt really find anything. $800 later and a lot of work I didnt really need I got it back together and its not any better so when I have time Im going to go after the carb again. One thing I discoverd with mine (using a DS2 dizzy with manifold vac) is if I left the vacuum hose off for the dizzy (causing a leak) it smoothed out slightly. I then got my hand vac pump and brought the timing back to the high teens and adjusted the mixture screw with the vac leak and the thing just purrrrrsssss. My guess is that its an issue with the fuel dribbling down the side of the manifold or carb or something like that and the vac leak in the manifold helps to break it up. One thing I tried is moving the throttle blade so it touches the wall on the oppsite side and the gap is on the side with the idle ports and screw. This way all the airflow is on the side with the fuel. It helped a bit and now at least the car does not stall at long stop lights. That tells me Im on the right track and at least now I know that I have a solid motor.

 

[Anonymous]

I did make sure to set the idle when the car was in drive, and you're right it does idle near 700 when it is in park. The idle still remains rough and choppy, and when you drive the car it does not accelerate smoothly, but rough and choppy.

I have set the timing, idle, and dwell to specs and made sure that they remain there but it still doesn't want to smooth out.

I also want to add that this is the third carb (autolite 1100) that has been on the car...kind of a long story but changing the carb does not correct this problem.

If anybody has any suggestions I would be very appreciative.

 

[Anonymous]

When messing with the idle mixture screw moving the screw one turn does not really change anything. If I tighten the screw too much (more fuel) then the car chokes and dies...however, I can actually remove the mixture screw by loosening it all the way and nothing happens.

Does this sound like a carb problem? This like I said is the third rebuilt carb I have put on the car. I don't mind opening the carb up, but I am kind of a newbie when it comes to carbs and I don't know if I would know what to be looking for or what to adjust. If there was some book or manual or someone had any advice, I would really appreciate it.

Thank you.

 

[Bort62]

Sounds a lot like a Vac leak to me.

That may or may not be a carb problem. Parts-store rebuilt carbs have a pretty bad reputation on here.

 

[woodbutcher]

Have you checked the vacuum line(at both ends)that controls the tranny modulator?
Leo

 

[Anonymous]

I checked and replaced both rubber vacuum hoses going to the transmission modulator, and I tried spraying starter fluid near the base of the carb and i couldn't get the idle to smooth out. I know that I have the points gaped correctly and the dwell set where it belongs...and I have the timing at 12 degress T.D.C. ...but it seems like no matter where the timing is the car does not smooth out.

Also I wanted to reiterate that adjusting the mixture screw on the carb has no affect on the idle whatsoever...until it gets to the point where the carb is getting too much fuel to breath.

Again any ideas or advice would be appreciated...I am begining to lose my patience with this car.

Thank you.

 

[Bort62]

Again any ideas or advice would be appreciated...I am begining to lose my patience with this car.

Thank you.

Send it over here.

 

[66 Fastback]

I don't think it is a carburetor issue, especially since several carbs have had the same problem.

Have you tested the vacuum advance motor on the distributor for a leak?
The old one on my Load-a-matic was leaking. Rig up some fittings and an hose and suck on the diaphram to see if it holds vacuum.

Have you checked to see that the distributor advance is working?
When you rev the engine, does the timing light indicate that the vacuuum advance is functioning?

Finally, you may want to check to see if the timing mark on the harmonic balancer ring is still in its correct position. Pull the #1 Spark plug. Note the location of the #1 post on the distributor cap relative to the base of the distributor and remove the cap. Stick and long stick or screwdriver in the #1 cyl and rotate the engine by hand. When the engine is at TDC of the #1 cyl (on the compression stroke), the screwdriver should be about to start falling down, the timing mark on the balancer should line up with the TDC scale on the engine, and the distributo rotor should point to where the #1 post or tower of the distributor cap is located. If all this lines up on the compression stroke, you have good news. If not, the ring on the balancer has slipped, and timing with a timing light will be difficult and usually incorrect. Replace the balancer and time to spec.
Doug

 

[ludwig]

Replace the balancer and time to spec.

Make a new mark at TDC with a thinline white pen and time to spec. You can replace later if neccessary.

 

[woodbutcher]

Hi falude,don`t mean to sound silly.Did you check the STEEL part of the tranny modulator line?Had same problem on my 84 F150 with engine roughness.Turned out to be a hole the size of the shaft of a straightpin.Drove me up a wall till I replaced the steel line.Tranny started shifting properly to.
Leo

 

[Anonymous]

Okay I am happy now. I think that I have solved or almost solved the problem. I found a small vacuum leak near the base of the carb so I removed it and put a new gasket down. The true problem, however, I believe that I found after searching through a bunch of old threads.

I thought just for the hell of it that I would pull the plugs to check them, not believing that this would have any bearing on the issue as I had replaced them less than five thousand miles ago. Well, to put it mildly, I was way wrong. Each and every plug was in horrible condition.

So after installing new plugs and resetting the dwell and timing I fired the car up and it was amazing how much the idle had smoothed out.

However, a new problem has come up. I don't know how, but the choke is now stuck open on the carb. I need to figure out how to correct this, as the car will not kick down after it warms up. So just to test the car out I turned the choke way down, and the car is running way better.

I appreciate all of your advice and help. If anybody has any suggestions about the adjusting the choke, I would appreciate it.

Thank you.