Distributor Fully Loose? Misfiring intermittently because of this? (VIDEO)

[eightynine4x4]

(1989 2.9 V6 Automatic)

IMG_7157.MOV

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Hey all,
So I have a few misfiring symptoms leading me to cleaning up and/or replacing some of the firing electricals in the engine, so after a few other things were addressed I decided to pop off the distributor cap to take a look at the health.
It turns out, my whole distributor is fully loose. (see video above) I had sort of noticed it in the past but never touched it other than popping off plug wires, but was assuming that the system was self contained somehow and performance alignment wasn't coordinated with the cap.
But upon looking at the design inside, it looks like my rotor alignment is 100% in flux at all times, since the shaft/rotor is locked in place with the engine but the cap and connections are free to slowly rotate this way or that as the engine vibrates.
Seems to me like it's just been pure luck that the firing is even half decent, and I'm probably not doing any good service to the truck with the rotor alignment being hit or miss. Probably gunking up my plugs all the time too, or doing worse things. The truck continues to be reliable and run pretty well as i keep working on it, but this cap issue would explain why startup is sometimes perfect sometimes not, despite addressing other startup aspects already. It would also explain why sometimes the engine sounds smooth, but other times it misfires. The cap is just dancing around.

Am I misinterpreting this all? Shouldn't the distributor cap be locked in place? And how is it supposed to lock in place? I didn't see anything obvious, such as any bolts or clamps, but maybe i'm missing it.

 

[Uncle Gump]

For sure the distributer needs to be clamped in position... after base timing is set.

Look way down at the base of the distributor shaft for the clamp and hold down bolt. If it doesn't have one... it's missing and you need one.

 

[eightynine4x4]

Ok thanks. I think i found it and will tighten it to see if it does tighten the distributor base segement.

Just so i understand correctly... This clamp down bolt is HOW we align the rotor to position 1, correct? This is all assuming proper TDC via hand motor cranking. Once the motor is TDC, then we make sure the distributor base (hand marked to show position 1) is lining up to the rotor point? Putting the cap back on properly, assumed also.
The Haynes isn't super clear about this all since it assumes the distributor base is already in the correct clamped position.

For sure the distributer needs to be clamped in position... after base timing is set.

Look way down at the base of the distributor shaft for the clamp and hold down bolt. If it doesn't have one... it's missing and you need one.

 

[Uncle Gump]

Did you have the distributor out?

 

[RonD]

Pretty much all distributors use the same method to hold them tight but still allow them to be loosened to set base spark timing and then be re-tightened

Bolt and forked "washer" setup seen here: http://www.dodurango.net/images/books/509/4/index.147.gif


On the 2.9l TFI spark system there is a SPOUT connector, looks like this: https://www.fordforumsonline.com/attachments/spout-jpg.866/

You need a timing light to fine tune base spark timing AFTER unplugging SPOUT connector
On 2.9l Rangers the SPOUT connector is near distributor on its wiring harness, usually passenger side on top of lower intake manifold

Yes, for gross spark timing, just to get engine running, you rotate distributor so #1 spark plug wire on the cap is lined up with the Rotor on the distributor when crank shaft is at 0deg TDC

Once engine can be started, let it warm up, 5min, then shut it off and unplug SPOUT connector and hook up timing light
Restart engine
Set based spark timing at 10deg Before TDC, some prefer 12deg BTDC, drivers choice
Then tighten up distributor Hold Down bolt
Shut off engine
Reconnect SPOUT
Start engine and drive vehicle to see how it runs under load

 

[eightynine4x4]

Ok thanks.
All i have done is take off the distributor cap. The base was already exactly as loose as it is in the video. I think maybe it just happened to be sitting in a somewhat functional position, by luck, for a long time now.
I see that i do have the washer in that spot.
I didn't look for, or touch, any other connectors so I'm assuming that if i have a SPOUT connector that it's connected.

I think this is my method..
1. Put cap back on, mark with a Sharpie both the distributor cap for position 1 and also the base for position 1, with the mount screws holding it cleanly together.
2. Remove the cap
3. Get engine in TDC
4. Observe the distributor base marking for position 1, and turn the distributor base so that it lines up exactly with the rotor point, and bolt tighten it down.
5. Put cap and wires all back in place

After that the engine should in theory be at least running as intended, if coarsely. Then I'll look into the SPOUT stuff and any other timing refinements. I don't have a timing light though.

Bolt and forked "washer" setup seen here: http://www.dodurango.net/images/books/509/4/index.147.gif


On the 2.9l TFI spark system there is a SPOUT connector, looks like this: https://www.fordforumsonline.com/attachments/spout-jpg.866/

 

[Uncle Gump]

It already runs... you don't have t do any of that.

Find the SPOUT connector and do what RonD described. Just have the proper tool to tighten the distributor down once you have the timing set.

 

[eightynine4x4]

It already runs... you don't have t do any of that.

Find the SPOUT connector and do what RonD described. Just have the proper tool to tighten the distributor down once you have the timing set.

I haven’t tried running it since discovering distributor base was loose and turning it by hand this way and that. If yesterday it was decently aligned, that alignment is totally gone right now. I think that means I have to find TDC again, and put the distributor into position 1 and clamp it down. Right?

 

[Uncle Gump]

No... just turn it to a position until it fires up... then turn a bit until it stays running the best you can get it. Warm it up and follow what RonD said.

 

[eightynine4x4]

No... just turn it to a position until it fires up... then turn a bit until it stays running the best you can get it. Warm it up and follow what RonD said.

I think I understand, but my issue is that I have no idea how the distributor should be first aligned for the engine to even run. The looseness allows me to rotate it up to like 90 degrees. It could have been in nearly any spot, as the video shows.
By the way, isn't there supposed to be some marking on the front of engine somewhere for TDC?

 

[RonD]

Yes, there will be TDC marks on harmonic balancer(crank pulley) and on the Front engine cover

There are two types
A single line/mark on the harmonic balancer, and then Before and After degrees on the cover, like this: https://www.speednik.com/wp-content/blogs.dir/1/files/imp/TDC-02.jpg

And then a single pointer on the cover, and before and after lines/marks on the harmonic balancer, like this: https://www.scottysretroworkshop.co.uk/wp-content/uploads/2020/11/Ignition-timing-marks-may-be-found-on-the-crankshaft-pulley-at-the-front-of-the-engine.-Here-the-scale-is-marked-on-the-pulley.jpg

You often have the clean these up with emory cloth(sand paper) or ??, to see the marks
Wiping the marks with paint on a cloth will leave the paint only in the recessed areas to make them more visible

You can get a distributor engine running without a timing light
But you can't get it running well without one, especially when its fuel injected and computer controls the idle

Once engine is warmed up you could unplug the IAC Valve so idle is not adjustable by computer, and then with SPOUT unplugged use a Vacuum gauge to adjust base spark timing

Timing light is BETTER and EASIER, lol

 

[eightynine4x4]

Thank you! I attempted to clean stuff up to get a good pre stamped reading on TDC but it became it’s own project (of course).
So I just ended up installing a fresh rotor and distributor cap and approximating where jt should be and got the engine to fire up pretty nicely. I don’t have the right size wrench/handle to get in and tighten the bolt so will do this soon and also start planning to be able to do a proper timing adjustment with a light.
question.. do we need dialectric grease in the rotor/cap points? I can pop it back open and put in some in. Just forgot that step.

 

[ecgreen]

This forum is awesome.

 

[gaz]

89,
If your engine weren't already @TDC, it wouldn't run.

Just warm it up, turn it off, disconnect the spout. Then start it and set the distributor timing with a timing light. Once correct, turn the engine off, reconnect the spout are you should be running well enough to perform any further needed troubleshooting.

 

[eightynine4x4]

89,
If your engine weren't already @TDC, it wouldn't run.

Just warm it up, turn it off, disconnect the spout. Then start it and set the distributor timing with a timing light. Once correct, turn the engine off, reconnect the spout are you should be running well enough to perform any further needed troubleshooting.

I have some irradic surging and dipping rpm action so I’m positive it’s not very well aligned. But it runs and doesn’t stall.
I did discover the core issue though.. the bolt is in some way F’d. It turns a bit but doesn’t come even close to tightening enough. I will need to inspect it a little further. I’ll take it fully out tomorrow and see if it’s just rust and grime inhibiting it. If I can’t get the bolt to ever tighten, maybe there’s a bottom part of the clamping section that’s broken or missing.
What’s interesting is that just tweaking the rotation of the distributor cap, I can get some wildy different results in the engine performance. In one particular go at it, engine ticking disappeared, making me think that my “ticking” is not every mans 2.9 ticking, and may relate more to poor timing than to oil flow in the upper engine.