5.0 Should I Stab In My Distributor At 0 On Damper Or 10 Btdc?

Discussion in 'Fox 5.0 Mustang Tech' started by killjoy, Sep 22, 2012.

  1. car was running took the dis out now im putting it back in and most of the info im getting off the internet is telling me to get the damper at 10 btdc and put the rotor button on #1 in the cap. when i put it in the first time it was set to 0 on the damper then i timed it with a light it allways just felt weak to me compared to my brothers car which is almost the same as mine.
    just wondering what some people might suggest.thanks

    89 gt gt40 heads intake, big cam, under drive pulleys, full length headers, non stock throttle body and c&l maf,cold air intake,a9l computer,automatic aod.
  2. It doesn't make much difference, you still need a timing light to get the timing set right. Check the local auto parts store to see if the will rent/loan a timing light.

    Putting the distributor back in and setting the timing.

    You can forget about anything beyond this point if you don't have access to a timing light. You will never get the timing set right without one.

    Putting the distributor back in is fairly simple. Pull #1 sparkplug, put your finger in the sparkplug hole, crank the engine until you feel compression. Then line up the TDC mark on the balancer with the pointer on the engine block.

    The distributor starts out with the #1 plug wire lined up at about 12:00 with you facing it. Align the rotor to about 11:00, since it will turn clockwise as it slides into place.

    Align the distributor rotor up with the #1 position marked on the cap, slide the distributor down into the block, (you may have to wiggle the rotor slightly to get the gear to engage) and then note where the rotor is pointing.
    If it still lines up with #1 position on the cap, install the clamp and bolt. If not, pull it out and turn 1 tooth forwards or backwards and try again. Put the #1 spark plug back in and tighten it down, put the clamp on the distributor, but don't tighten it too much, as you will have to move the distributor to set the timing. Note that there is no such thing as one tooth off on a 5.0 Mustang. If it doesn't align perfectly with #1 position, you can turn the distributor until it does. The only problem is that if you are too far one way or the other, you can't turn the distributor enough to get the 10-14 degree optimum timing range.

    Setting the timing:
    Paint the mark on the harmonic balancer with paint -choose 10 degrees BTC or 14 degrees BTC or something else if you have NO2 or other power adder. I try to paint TDC red, 10 degrees BTC white and 14 degrees BTC blue.

    10 degrees BTC is towards the drivers side marks.

    Note: setting the timing beyond the 10 degree mark will give you a little more low speed acceleration. BUT you will need to run 93 octane to avoid pinging and engine damage. Pinging is very hard to hear at full throttle, so it could be present and you would not hear it.

    Simplified diagram of what it looks like. Not all the marks are shown for ease of viewing.

    ATC ' ' ' ' ' ' ' ' ' '!' ' ' ' ' ' ' ' ' ' BTC
    ---------------- > Direction of Rotation as viewed standing in front of the engine.

    The ' is 2 degrees.
    The ! is TDC
    The ' is 10 degrees BTC
    Set the timing 5 marks BTC. Or if you prefer, 5 marks towards the driver's side to get 10 degrees.

    To get 14 degrees, set it 7 marks BTC. Or if you prefer, 7 marks towards the driver's side to get 14 degrees.

    The paint marks you make are your friends if you do it correctly. They are much easier to see that the marks machined into the harmonic balancer hub.

    At this point hook up all the wires, get out the timing light. Connect timing light up to battery & #1 spark plug. Then start the engine.

    Remove the SPOUT connector (do a search if you want a picture of the SPOUT connector) It is the 2 pin rectangular plug on the distributor wiring harness. Only the EFI Mustang engines have a SPOUT. If yours is not EFI, check for a SPOUT: if you don’t find one, skip any instructions regarding the SPOUT
    Warning: there are only two places the SPOUT should be when you time the engine. The first place is in your pocket while you are setting the timing and the second is back in the harness when you finish. The little bugger is too easy to lose and too hard to find a replacement.

    Start engine, loosen distributor hold down with a 1/2" universal socket. Shine the timing light on the marks and turn the distributor until the mark lines up with the edge of the timing pointer. Tighten down the distributor hold down bolt, Replace the SPOUT connector and you are done.

    The HO firing order is 1-3-7-2-6-5-4-8.
    Non HO firing order is 1-5-4-2-6-3-7-8

  3. Dude why dont you make some vidoes of some stuff like this it would be nice to watch this kind of thing for our old pushrod 5.0!
  4. I am not at all photogenic. If I found someone everyone would watch, they would be concentrating on her and not what was happening....
  5. Was kinda curious, so I thought I'd bump this one back to the top.

    I've always set my distributor using the method outlined by @jrichker above, utilizing TDC as my starting point, then advancing the distributor by hand to my optimum ignition timing.

    Now....I realize plug and rotor location don't make a difference as long as they both start in line with one and other at the number 1 firing position in say a batch fire, or carbureted fuel system, but SEFI requires that the #1 start position also be synchronized with the PIP signal to correspond proper injector timing sequence. With me so far?

    Now here is what has got my mind going. If aligning the rotor, #1 plug position and stator sensor magnet at the TDC event, is it not then moved out of alignment once the distributor is rotated the 10-14 degrees advance after initial set up to achieve optimal ignition timing? The rotor and sensor magnet are no long in alignment with one and other after the distributor is physically advance...which I would think buggers up the injector sequencing?

    As such....would it not be better to stab the distributor at 14-degrees advance (or wherever your vehicle runs happiest) of TDC right from the get go, in order to keep all components (rotor, #1 plug and stator sensor magnet) aligned with one and other? I would think doing so would start you at, or at least within a degree or two of optimum ignition timing, which would require minimal manual manipulation of the distributer and ensure the rotor, #1 plug and stator sensor magnet all remained in sync with one and other....thus providing optimum conditions for proper ignition and fuel timing events?

    Am I looking at this the wrong way here? :shrug:
  6. So.....no opinions on this one, huh? :shrug:
  7. I have been away from reliable Internet connection, so I have been unable to answer your question. The few degrees difference between 10 degrees and 14 degrees isn't going to make any measurable difference to the computers injector timing. Some Ford EFI engines use bank firing injectors that fire 4 injectors at a time and show little difference from the sequential firing injectors except for idle and fuel economy results. See http://oldfuelinjection.com/?p=4 for more information.
  8. Between 10 and 14-degree's, no....but what about 0 and 14-degree's? Remember, the recommended method is to stab the distributor is at TDC. From there we physically turn the distributor to 14 advance. That's a long way from the original 0-degree's where the rotor, #1 plug position and stator sensor magnet all lined up.

    If lining up the rotor, #1 plug position and stator sensor magnet provides one with the best idle, drivability and economy possible, would it not be beneficial to stab the distributor at 14 BTDC, instead of TDC? That way, you would start out with both the 14-degree's of timing and keep all components in line for optimal fire and injector sequencing?

    Are you seeing where I'm coming from? :shrug:
  9. ummmm, maybe im missing something cause its early and i just skimmed, but doesnt the fact that the stator rotates with the distributor shaft (and the pickup with the body) and is keyed to the rotor nullify any of that?
  10. I think you missed the point about bank firing of the injectors. In a bank firing injector EFI engine, some of the injectors will pulse while the intake valve for the cylinder they service is closed. That's way more out of sync than the 14-16 degrees advance from TDC when installing the distributor's initial position.
  11. That's what I'm trying to determine? While it's clear to me that the stator and the rotor pickup rotate in unison with one and other with the distributor shaft and that the sensor magnet and #1 spark plug position also rotate in unison with one and other (although separately from the other two)....I question whether or not the 3-points must start in a synchronized position with one and other on the firing position for best possible results? After all, If the spark is set to fire 14-degree's before the stator sends the injector sequencing still in synchronization with the event? It seems to me, that the whole process now takes place 14-degree's after the spark has fired?

    The way I see it, they're only truly synchronized when the distributor is initially stabbed and that all points (#1 plug, rotor, magnet and stator) are lined up with one and other, before manually advancing the distributor. The moment the distributor body is rotated clockwise in order to provide the ignition advance, these points are no longer in alignment with one and other?

    It seems to me, that it would make sense then to stab the distributor at 14 BTDC (or whatever you optimal ignition timing is), rather than TDC, so that no, or at the very least minimal adjustment beyond that point would be necessary to dial in ignition advance....thus keeping all points in alignment and providing the best relationship between spark and injector sequencing.

    I understand how it works with bank firing, but that's not the system our 5.0L HO's were set up with. Bank (or batch) firing the injectors is a proven set up, but doesn't have the ability for fine tuning idle and low speed driving characteristics that SEFI has. The excerpts in the article you posted touch on this very point....

    What I'm asking is...rather than setting it up as "good enough and let the computer compensate for the difference", wouldn't we be better served to set it up as precisely as we are able to right off the bat? Would it not make sense to take full advantage of the sequential firing system we were saddled with, instead of treating it like a bank fire set up that we were not? :shrug:
  12. Afaik the ecu doesn't care what base timing is, it just adds advance based on how many times that short wave goes by per minute. This why setting it over the stock 10 degrees works in the first place. As long as it starts it doesn't really matter where it's set on the initial stab, and if it really is an issue to you, reset the ecu and it will go from there
    jrichker likes this.
  13. I mark the lower part of the distributor and the lower intake with a dot of white out, or a marker before I reomove the distributor. That way when I reinstall it @ #1 I just line up the dots and it's in the neighborhood.
  14. That's great as long as you know the distributor was stabbed correctly to start with....or you're not doing a H/C/I swap and have to start from scratch. After seeing what the previous owner did to my car, I trust nothing to be in it's correct location. lol
  15. LOL. I've dealt with those hacked up nightmare of a car before. I had a guy (kid actually) that butchered up the car so bad doing his "mods", the car was undriveable. He swapped heads and reused the old head gaskets, bolts, pushrods, lifters,etc., and he wondered why the car wouldn't run.
  16. I think you are starting to get into the territory of rotor phasing which is not a concern at all with the stock TFI setup. I know as far as my FAST SEFI I have a crank and cam signal that both happen at different timing event and a phasable rotor. Crank event for me is 50 degrees before TDC and the Cam event is 60 degrees before TDC. I made an adjustable reluctor in my distributor for cam phasing and use an adjustable crank trigger as well. Once my initial setup is done all of my timing changes happen in the ecu. This is where I think you are going with this, but this is far more complex than the factory TFI. The pip signal happens 8 times with the as the tangs pass the magnet in the dist. housing. so as far as syncing goes it is not as big of on issue. Stabbed at 0 or 14 it makes no difference as the end result is the same. I personally would stab it at 10 to have it close for an easy start up and adjust from there.
  17. i havent really kept up with your build, so forgive my ignorance, but is this some kind of COP/edis setup? thats the only thing i can think of where phasing (and crank triggers) would be needed, if theres some other app for em i'd like to know just for the hell of it.

    one thing to keep in mine about the stock eec-iv is that its really not as smart as people seem to think, which is what makes it as adaptable as it is. You can do a fair bit of tuning on the car without even touching the ecu, something that cant be said of most newer factory ecu's. hell, most newer cars need a tuner just to deal with a cai, where a eec-iv doesnt really care as long as it can adjust enough to make the 02's read right.
  18. I couldn't agree with you more here!
    As far as my build, its a traditional pro billet modified for a cam pick up with an adjustable reluctor. This drives the xfi 2.0 sequential injection. The timing and phasing is super critical with extreme cylinder pressures and that is the reason for all the atypical parts. We've run over 35 lbs of boost through my sbf in testing some new blower concepts.
  19. You bring up a good topic. Injector timing is calculated based off of Load and RPM tables. So just because the #1 vane on the stator passes by the pickup, doesnt mean thats the timing event for the injector. Its just the start of the number sequence. Further more, the #1 vane, is the same for Spark and Injectors, so its not going to get out of sync.

    Well, the rotor and stator wont be aligned anyways. The vane for #1 is offset to the right.

    Either is fine, but dont overthink it. You will wind up in the same place regardless of the two methods mentioned here. One just requires a lesser amount of adjustment. But, the #1 vane will still be crossing the pickup at the same point in crankshaft degrees.
    Gearbanger 101 likes this.