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Timing adjustment


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I went to check the timing on my 73 Grande after installing a Pertronix ignition module, and noticed the timing was way off (30+ degrees advanced). I retarded the timing to 8 BTDC, and the car ran like crap. When I went to restart it, the engine backfired into the exhaust so i know the timing was too retarded. I advanced the distributor back to where the engine was happiest, and for the heck of it threw the timing light back on it. The timing marks seem to coincide with the peephole looking thing below the timing tang. What is that peephole? Is that what I'm supposed to use for timing reference, or has the outer ring slipped on the harmonic dampener?

timing.png

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boy your marker sure looks different then mine. i just have a flat blade on the top.

mine mounts with 2 bolts into front of block. i'd have to say u got the wrong marker and doing the timing by ear is gonna be way better then using that marker.

with the pertronix did u bypass the resistor wire and used 12v or used the resistor wire voltage?? i did the pertronix also and just used resist wire and no problems.

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I wasn't aware that they had a resistor on that year. I'm getting 12 volts at the coil so I didn't even think about it. I don't think that would throw off the timing mark though. I got the car up on ramps today so I could get a close look at the harmonic balancer, and it looks in great shape. The rubber is perfectly intact, and not cracked at all. Is it possible the balancer still could have slipped on the hub? The car only has 23k miles.

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Goforbroke,

I believe that hole was for magnetic timing check at MoCo during assembly.

on later models of ford engines we had a probe that slid in there from our diagnostic equiptment.

There (should ) be a  corresponding slot cut in your harmonic balancer.

this is Not what you want to use to time the engine.

I would be interested in looking at the instructions of the pertronics kit.

also make sure the little arm from the vacuum advance unit is secured to the advance plate and actually moves when vacuum is applied to it, 2 vacuum hoses on the advance canister ?

Boilermaster

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I read through the pertronix instructions before I installed the unit, but iii checked the voltage while it was running, and I guess that throws off the volt meter. I checked it in the KOEO position, and I was getting 7 volts at the coil, so there is a resistor. Would you happen to know where it's mounted? I looked all over the engine bay, and was unable to locate it. Also there is only one vacuum hose connected to the distributor, and I disconnect, and plug it when I'm checking the timing.

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it's not mounted anywhere.. it's a resistor wire. question.. do u have a tach?? if so it runs off that wire so removing it will kill the tach. just run it the way u have it wired now.

mine is wired this way and for a yr no issues.. yes u would get a heavier spark if u by pass it, but if it's a driver then leave it alone.

with the balancer.. if it's orig then yes u have a lot more chance of sliding. but if new 23k ago i doubt it.

again hopefully someone will chime in for i really feel u have the wrong marker on the engine

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I read through the pertronix instructions before I installed the unit, but iii checked the voltage while it was running, and I guess that throws off the volt meter. I checked it in the KOEO position, and I was getting 7 volts at the coil, so there is a resistor. Would you happen to know where it's mounted? I looked all over the engine bay, and was unable to locate it. Also there is only one vacuum hose connected to the distributor, and I disconnect, and plug it when I'm checking the timing.

 

 I'm not really up on 73's, so parts and other things could be far different than the 71 I'm familiar with, but I do have quite a bit of experience with Pertronix modules now, having gone through this routine myself.

First, you did NOT say which Pertronix Ignitor module you bought. That is very important for us to know. ALL modules should be run on a full 12V at the coil, engine running (or key on?). However, the basic Ignitor I , can run with a resisted voltage according to Pertronix. Likewise the Ignitor II, but NOT recommended. The Ignitor III MUST be run with a full 12 V UNRESISTED power supply. From my personal and costly experience, I would NOT suggest using the Ignitor III. I have written about this issue many times. It is the construction of the module for the Ford application that was a major problem, not the electronics. Unless Pertronix have redesigned the stupid little plastic bearing between the two plates, you WILL have timing issues because the top plate will move around, altering the timing. I'm not going into the full details here, but in a nut-shell Pertronix replaced the Ignitor III with a II and a free matching coil, problem solved. ALL Pertronix modules should be used with the MATCHING coil.

On a 71, the resistor wire is located were the harness plug on the s/column meet the main harness connector. Is it the same on a 73, I don't know for sure. It is a large PINK wire in the main harness connector. As mentioned I believe that wire powers the tach, but as I don't have one, I don't know for sure. In the instructions for the Ignitor III module, it requires a#10 wire directly to the coil. In my case, I pulled the pink wire connector pin out, unsoldered the wire and inserted and soldered the "red" #10 wire. It was not an easy job I'll add. No going back now!! However, it is possible to add a Chrysler style ballast resistor on the firewall if you absolutely need it for a return to points or maybe that tach, just guessing on the tach! You will need to make sure that it has the correct ohms. (there are many types)

Geoff.

 I learn something new every day!

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Thanks for all the feedback. Everything is stock on the car so I just went with the Ignitor I module. The car does not have a tach, but if you can run resisted supply to the coil with the Ignitor I, I'll just leave it alone. I did purchase the 1.5 ohm coil to install with the module as well. I think my concern is more with the timing marks being off on the balancer. The car has been family owned since new, and according to my father, timing the engine in the past hasn't been a problem, which makes me think the balancer has slipped. I've been chasing down a rough idle as well. The car drives fine, but i'll be damned if i can get the thing to idle smooth. The worst thing you can do to a car is let it sit...

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Thanks for all the feedback. Everything is stock on the car so I just went with the Ignitor I module. The car does not have a tach, but if you can run resisted supply to the coil with the Ignitor I, I'll just leave it alone. I did purchase the 1.5 ohm coil to install with the module as well. I think my concern is more with the timing marks being off on the balancer. The car has been family owned since new, and according to my father, timing the engine in the past hasn't been a problem, which makes me think the balancer has slipped. I've been chasing down a rough idle as well. The car drives fine, but i'll be damned if i can get the thing to idle smooth. The worst thing you can do to a car is let it sit...

 

 Thanks for telling us what module you have. I think you'll be fine running resisted, but if you have any concerns, you could contact PerTronix on their website. In fact, I would suggest doing that to be sure. Who knows, I may have been told incorrectly, so it doesn't hurt to get another opinion. I'm definitely NOT up on electronic stuff, never claimed to be, so best to be sure.

So, your car has a well known history, that's great. Hopefully your Dad kept all the service records, great for historical records and to help with what has or hasn't been replaced over time.

There are a lot of 73 owners on here, so I'm a bit surprised some have not chimed in to help with your issue. As we know, there were a lot of changes because of emissions stuff between 71 and 73 and way beyond my experience. Your issue could be many things, but I'm starting to wonder what has been done if anything to your carb. Is it the original too? I'm wondering if the idle circuit is clogged up as you say it drives fine on the main circuit. It may be time for a rebuild or better yet a replacement. Again that is out of my comfort zone on a 73, but I would suggest a Holley 670 Street Avenger or a Quick Fuel of similar size, but no bigger than a 750.

In the mean time, buy a bottle of "Sea Foam" fuel system treatment. This is amazing stuff and it will clean out any gunk that could be causing issues anywhere in the fuel system. While you're at it, replace your fuel filter(s), vacuum lines etc. It doesn't make sense to me that it drives fine, but won't idle, that's why I think there is something else going on besides a suspect balancer. My feeling is that if your balancer HAS shifted and you re-time the engine to that, it will run like crap all the way through the rev range. Replace the balancer with a GOOD brand if you have any doubts and start again.

Keep us up on progress,

Geoff.

Geoff.

 I learn something new every day!

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