I am in need of replacing the distributor in my 1979 F100 302.

I checked Chilton manual and it says that I mark the distributor housing, rotor and engine block when taking the distributor out. I am wondering how does this apply when I am putting a new distributor?

Also, it says that if engine needs rotated, I need to put the No.1 piston is at TDC. Thereafter, align the timing mark. What timing marks is the manual taking about? Is it the timing mark in the timing chain sproket or the timing mark in the crankshaft that you use to set base timing?

Any help is appreciated.

 

To remove the distributor, mark your crankshaft pulley at TDC. Look at your distributor cap, there should be a “1” on it, note its position, if there is not a one on it, follow to the number one plug wire back to the cap, remove the cap. Turn the engine around until the rotor in the distributor almost points to where the “1” was, then look at the crankshaft pulley and turn the engine in the same direction until the pointer points at "TDC". Do not move the engine at all until the distributor is back in. Note the rotor position to the distributor. Unwire the distributor, remove the hold down bolt and pull the distributor out. Note how much the rotor moves while pulling the distributor out.

Put it back in with rotor pointing to about where it was on the other distributor when it came out. Position the distributor in about the same position it was and push it in. Hopefully the oil pump drive shaft went in and the rotor is pointing to number one spark plug position. If not pull it back up and move the rotor a little in the right direction and try again. Hand tighten the hold down bolt, put the cap back on. Hook your timing light to the number 1 plug wire, remove and plug the vacuum line from the advance diaphragm, start the engine and twist the distributor until the pointer points to the required degrees of advance. Tighten the hold down bolt and recheck. Remove the timing light and hook the hose back up to the distributor advance diaphragm. And you got it.
You can mark the rotors position on the old distributor as you take it out and then use it as a reference when putting the new one in.

Good luck

 

Cool !! I will try that out soon and let you know how it went.

 

Ok. Changed the distributor, and here is the scoop:

1) Found TDC of compression stroke for no. 1 Cylinder. Noted that distributor rotor was at no.1 coil. Marked position of rotor in distributor housing and block. Marked crankshaft for TDC.
2) Removed old distributor and noted how much it rotated when taking it out.
3) Put new distributor in, darn thing won't go in. Found that shaft was tad bit bigger. Took a file to it and scraped couple times and distributor went in. But this time got stuck on the oil pump shaft. No matter what you do, it won't go in.
4) Finally, had to rotate engine to make distributor go in all the way. Result, timing messed up.
5) Took the distributor out again, found the TDC, put rotor at no.1 coil and put it back in. After, a lot of trial and error, found that the only position where truck would start without spitting and backfiring is not where the rotor position for the no. 1 coil position was for the old distributor. The new position is couple degrees anticlockwise from the old position. Seems like it is at a retarded position.
6) Anyway, truck started fine and revs ok - can't say it really satisfied me. Took the timing light to it and saw that timing mark on crankshaft is a little advanced. Well, there was no further room for me to move the distributor housing anti-clockwise to put mark exactly where it belongs.
7) PROBLEMO: when driving down at about 30 is fine. But when you step on the gas, it pings !! Sucks !
I know my timing is messed. How do I fix it??!

Also, I got a reman distributor. At the top of the vacum advance, there is this hole that is pluged by an organe plastic thing. That hole was unplugged in my old distributor. What is that hole?

 

Sounds like you are about one or two teeth off, pull the distributor up just until you can just turn the rotor to the next tooth, let it back down. If hopefully the oil pump shaft will stay in, if not bump the engine until it dose. Make sure you turn the rotor in the right direction so that you can turn the distributor to the right timing mark.

Do the timing light thing again.

Would not know about a hole without seeing it.

 

Took the distributor out. Made sure that No.1 cylinder is at TDC at compression. Put the distributor back down making sure that rotor points to no.1 spark plug wire. After some trial and error, distributor went down completely and engaged the oil pump shaft as well. Truck started right up and idled better than before. Took it for a test drive and it did lot better than before. But I still get spark knock when there is load on the Engine - like climbing a hill. I use to get spark knock with my old distributor when climbing hill at highway speed. Now, it is a little worse then before. After the test drive, I took the timing light to the Engine again. When I timed it before, I took the vacuum advance off (plugged it) and made sure that timing mark is at its correct postion. (Dead in the middle of a metal pointer pointing towards the cranfshaft). But I see that when I hook the vacuum back up, the timing advances by about 8 - 10 degrees. Can this be causing the spark knock on load? Should I retard my timing a little bit when setting the base timing? Also, how do I find out if my engine is running a little lean (want to eliminate that possibility)?

 

With the vacuum disconnected and plugged and with the engine turning about 800 RPM, any faster and your Centrifugal Advance Mechanism will advance your timing and you will not set it right. Set timing at 10 Deg BTDC with the light. Now rev it up a little and watch the timing mark with the light, the Centrifugal Advance Mechanism will move the timing, if it don't we are setting the timing at to high an RPM or we have a bad Centrifugal Advance Mechanism. Now hook the vacuum back up and watch it as you rev it up again, the timing mark will move a little further, if it dose were good.
If it pings too much (unless the engine is running warm) you can try backing off the timing a little, this will give a little more power and less pinging but it will pollute more and may not pass pollution standards, that’s why they advance the timing specifications.

 

After I set my base timing at 10 degree BTDC, should the timing mark move any at all when I simply hook up the vacuum without reving the Engine? That's what is happening in my case. I also noticed that the rpm increased when the vacuum got hooked up. However, I did not check for the Centrifugal advance mechanism. I will do that tomorrow and post back.

 

This is all normal and OK.

 

Started the truck up and let it idle for about 15 - 20 minutes to make sure it is warm !! I made sure that engine is idling at less than 800 rpm. Disconnected vacuum advance and plugged the hose. Set the base timing at 8 degree BTDC. When I press on the throttle, I do not see the timing mark move. I bought this distributor two days back - remanufactured distributor. Question is, are all distributors suppose to have mechanical advance? When I hook up the vacuum, it advances fine. With the timing light, I can see that it is 23 degrees to bring the mark back to the pointer. I haven't taken it for a test drive yet to see if it pings anymore.

 

No, the Duraspark III and the later EEC IV did not.

But the Duraspark II did and I think you have a Duraspark II as they came out in 1977 and you have a 1979. I do not know when the Duraspark III came out but they had them in 1983. I have service manuals on the 1977 and 1983 but nothing for 1979.

If you take the rotor and try to turn it back and forth and if it moves about 1/2" back and forth under spring return then you have a distributor with mechanical advance. Try reducing you rpms to about 500 and then rev up to see if the mechanical advance works.

If you have a Duraspark II system and you have no play in the rotor then they sold you a bad distributor.

The Duraspark III system has an EEC Microprocessor and the Duraspark II system does not. Also the Duraspark III system has a crankshaft position sensor (it goes in that round hole on the timing pointer) and has no small wires going to the distributor.

 

I removed the Duraspark III system from my 1983 Ford this past Sunday, and replaced it with a Duraspark II, and a new module. Had to make a new wiring harness, but this truck has never run better now that its done.

I switched it out because the computer kept bouncing the timing around. The faster I drove, the higher the timing would go. Often, I couldn't start it when warm.

Now, there are no timing marks on my harmonic balancer. Guess its time for a trip to the junkyard for a 351W balancer!

 

The distributor is a reman motorcraft and not a duraspark. I will take the part number and re-post.
Anyway, I called the parts store and according to them, it has mech adv. Also, when I move the rotor, there is spring action on it just like you described. The parts store manager told me that mech adv. comes on as soon as you start the engine. Is that true? If that's true, I am not sure how I am going to test the mech adv. Maybe try the 500 rpms like you mentioned.
Now, I am getting spark knocks when I am driving up a hill at highway speed. Otherwise, there is no spark knock. I mentioned that to the parts store manager and he said that spark knock is very comon on older fords and even the manual says it. I don't know how much of that is true.

 

Motorcraft is the manufacture of the distributor and Duraspark II is the type of Ignition you have.

The parts store manager is wrong.
The mech. adv. will not start advancing until you reach about 700 rpms and will not fully reach its maximum advance until you reach about 2500 rpms.

Try setting you’re timing at 2-5 deg BTDC at 600 rpms with the vacuum line off and plugged and see if that helps your pinging.

Anyway here is what the FORD Manual says about it typed in verbatim.

1. Clean the surface and place a white mark on the proper degree line on the front damper and pointer according to specification noted on engine decal.

2. Disconnect the vacuum line(s) at the distributor and plug.

3. Connect timing light to No. 1 cylinder spark plug wire. Install engine speed tachometer. Loosen distributor hold down bolt.

4. Start engine, warm up and reduce idle speed to 600 RPM.

5. Adjust initial timing to specification by rotating the distributor against rotor rotation to advance timing or with rotor rotation to retard timing. When the white mark (step 1) is directly in line with pointer, ignition timing is then correct. Recheck timing when hold-down bolt is tight.

6. Check centrifugal advance by accelerating the engine (in neutral) to 2500 RPM. If ignition timing advance is noted during acceleration the centrifugal advance mechanism is functional. Refer to engine decal for specification.

7. To check Vacuum Advance, unplug and re-install carburetor source vacuum line (removed-step 2) to outer diaphragm (on dual diaphragm distributors). Accelerate engine to 2500 RPM. Total advance now should be greater than in prior step (centrifugal only) if advance mechanism is functional. If no additional advance is observed and vacuum is noted at the line to the diaphragm, remove distributor and make required repairs.

 

Try retarding your timing just a bit.

A Motorcraft distributor that does not use breaker points, and condenser, is a Duraspark. Either I, II, or III. The TFI-IV is another breed entirely.