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Quick question - where does you rotor point on TDC?


ecgreen

Well-Known Member
Joined
Sep 21, 2018
Messages
720
City
Dunbarton NH
Vehicle Year
1989
Engine
2.9 V6
Transmission
Manual
Total Lift
3"
Tire Size
33
If you are looking at the distributor standing in front of the vehicle, where does your rotor point when the engine is at TDC for cyl #1? A search of this forum said 11 O'Clock, which would mean that the rotor points to the passenger seat.

On mine, it points to the front driverside headlight - so around 5 O'Clock. Now my engine actually runs (but not awesomely - see other threads lol). Is this even possible if I am 180 deg off? Shouldn't it not run at all? Help the FNG understand please.
 
Sure youre at TDC on the compression stroke? It shouldnt run that far out.

Pull SPOUT connector and get a light and verify your at 10-12* BTDC.
 
Sure youre at TDC on the compression stroke? It shouldnt run that far out.

Pull SPOUT connector and get a light and verify your at 10-12* BTDC.

I hear you, it shouldn't run that far out. I checked it by cranking engine with finger over the spark plug hole. This even lined up roughly with the TC mark on the balancer. With the engine in this position, the rotor points to the 5 o'clock position - which I have read is 180 from where it should be.

I have timed it numerous times and always do it with the spout connector out. As I have written about in another thread, I am having some weird issues with that could certainly be timing related so I got to rethinking things. I need to re-do the timing again, as I was playing with the blanacer and watching the rotor to see if the chain is stretched. I'll re-do it today and go from there.
 
Mine's pointing at 12 o'clock, but yeah, sometimes when putting the distributor in, it's easy to accidentally put it in with the rotor pointing 180 degrees in the wrong direction. I think I tried to compensate for that by putting #1 plug wire at 5 O'clock at one time, because it's such a pain to reposition the distributor while the engine is in the truck. BUT, iirc, it wouldn't run right, so my lazy butt had to go back and reposition it anyway! Haha!
 
There is #1 TDC and #5 TDC that use the same 0deg mark on the crank pulley, because 1 and 5 are Match Pairs, their pistons are at TDC at the same time to balance the engine, 2/6, and 3/4 are the other Matched Pairs
Firing order on any engine shows you the Match Pairs used to balance an engine
2.9l, 3.0l, 4.0l = 1-4-2-5-3-6
when you split it and put first half above second half
1-4-2-
5-3-6
You see the Matched Pairs, works for any engine, 4cyl to V12

The distributor cap has #1 marked

So when properly timed the rotor can point at #1 or #5 when crank is at 0deg
Engine will run one-way but not the other way
If engine doesn't run then rotate crank to 0deg, rotor will be pointed at either 1 or 5 cap position
Then lift up distributor to release its cam gear and rotate rotor to opposition position, 5 or 1
Then put it back down
Timed

The position of #1 on the cap can be at any o'clock position, as long as rotor is timed for that position
So it comes down to convenience and wiring
You need to plug in the TFI wiring and unplug it, and you need enough room to loosen and tighten the distributor bolt, and enough room to rotate distributor to set the 10-12deg BTDC timing

So FIRST thing is to decide where YOU want the distributor to sit, so YOU can adjust and work on it easily
Then you just match #1 cap position and rotor to YOUR o'clock position

So there is no "right" position, there is easiest position and not-easy position, lol
Totally up to YOU


Now I have read that the TFI vanes in the distributor have a slight difference to mark #1 position, this would be more for sequential fuel injection than anything else and 1994 and older Rangers used Batch Fire injection, so using #1 cap mark is not really needed, but.......................its so simple to use it I would say just do it
 
That makes sense Ron, thanks. I re-did the initial timing and it runs A LOT better now. I found TDC and the dizzy fell in with the rotor pointing to about 11 O'Clock. The difference between how it runs now and the last go around is night and day. So what was up last time?!?! Perhaps I was a "tooth off" as they say?
 
Yes, maybe, but timing light should have told you that
 
The rotor can point anywhere you want it to all around the whole distributor. Stop it on #1 TDC, and point the rotor any direction you choose. Once the distributor is in place, make sure you put the #1 wire where the rotor is pointing, and then put all the other wires in the correct firing order sequence all around the cap. It will run fine like that. It doesn't know the difference.

What makes it better to run #1 where the factory had it, the sparkplug wires fit better and when you go to time it, the igniton module is not swinging around hitting something on the engine. And it doesn't confuse people like it did you when you went to work on it.
 
Yes, +1 ^^^^

And if the cap does have a #1 marker, why not use it, for the next poor bastard that might need to work on it, lol, because it could be YOU in a few years when you forgot what you did last time :)
 

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