random stalling and valve clatter 73 bronco

[Midnight]

I have a 73 Bronco 302 three speed. Around every six months it just decides it wants to die and not start up again, usually in the middle of an intersection or stop light. I usually end up towing it home and then when I get around to looking at it, It starts up just fine like nothing happened. I have changed fuel filters, pumps, cleaned hoses, put in a Pigtonix electronic ignition and other various items.
This happened last November, since then I have only driven it a few times, because of life stuff. When I pulled it out of the garage to give it a look over. I noticed a clicking noise that I am not sure was there before. Sounds kind of like some sort of valve clatter. I have revved the engine to see if the timing changes the noise, but it is so noisy I can't tell.
Timing issues are little above my pay grade, plus I just don't have the equipment to deal with it.
This leads me to two questions:
1. Any one have an opinion if the timing might be responsible for both problems, the clatter and random stalling?
2. Anyone had any luck with oil detergent or after market additives for the valve noise? I have heard mixed reviews. Oil just changed 400 miles ago, and pressure seems fine. Short of taking off the valve covers which i just did last year (to replace gaskets that were leaking) I am looking for alternatives.

Here are a couple of movies to get peoples opinion. Hopefully they work
Thanks if advance

IMG_1943.MOV

drive.google.com

IMG_1981.MOV

drive.google.com

 

[DirtDonk]

Hey Midnight. Haven’t even read it yet but I wanted to send this back to the top get it back to the first page and more eyes on it.
When I have a few extra minutes, I’ll go ahead and read and hopefully I can offer some help.

 

[DirtDonk]

Hmmm. I watched the videos and of course you hear a lot of other noises as well, but this time the ticking did stand out.
It does sound like a lifter or a rocker arm to me, but it’s well known these days that even a small exhaust leak in a manifold or a coupling, or even a loose spark plug, can make similar sounds.

A noise like that doesn’t usually indicate something that can stall an engine and keep it from restarting.
I’m not sure about that aspect of your problem yet.

Unlike some of the things you’ve read, I’m a huge fan of oil additives. They’ve always worked for me just as advertised, and I have extended the life of several of my engines.
Especially good for engines that spend a lot of their lives just sitting. A solvent based additive can loosen the varnish and gunk and free things up for a little bit more life before they have to be replaced.
The key here, though, is probably to not use them in a case where there is excessive caked on buildup inside the engine.
That can start to dissolve, but also break loose in chunks and cause trouble.
When you had the valve covers off, how did it look?

What oil are you using? And is it a high zinc oil to begin with, are you using a ZDDP additive by any chance?
In spite of some people saying that once a cam is broken in you never have to worry about that zinc again, but I’m not a believer yet.
Far too many older cams have seen an early death since the demise of zinc in the oils.
I like the old “trust, but verify” scenario.
But in the meantime, I’m playing it safe and adding zinc to any engine still running a flat tappet cam.

I’ll keep working on ideas for what’s causing the stalling, but hopefully others here will chime in as well.
In the meantime, the primary detective here is going to have to be you crawling around in the engine compartment and looking for anything loose, broken, miss adjusted, or just plain worn out.
Only you can find that.

 

[Dne007]

Gee, the engine sure purrs despite the noise. I'm curious about the solderless terminals at the coil, the integrity of the crimp unless they're soldered, then there's a long wire coming off you coil going somewhere? Where does it go? I think I'd wear some insulated gloves, while the engine is running, kind of play with wires at the coil, seeing the engine will abruptly die, or do something. Maybe even jiggle the ignition switch and see if any undesirable things occur?

Does the "clatter", taping noise lessen with the engine at operating temp? Kind of dumb, but I've seen a spark plug not completely screwed in making a ticking sound! lol I didn't do it! I use a long skinny screwdriver(about 2' long) as my stethescope, but beware around the fan and pulleys!!! Hey, even a fuel pump can clickity clack!

 

[DirtDonk]

If that other wire is a tachometer, disconnect it the next time it acts up. See if that lets you restart.
But while the tach is working, when the engine dies does the tachometer instantly go to zero while you’re still rolling? Or does it sort of keep going until you stop?
If it keeps going, it’s likely a fuel problem. If it abruptly drops to zero, it’s probably ignition related. Which may lead you back to a tachometer that is acting up.
Happens fairly often.

 

[gnpenning]

Along with the above have you checked for exhaust leaks?

If you have any questions about what good spark should look like or a good fuel shot now is the time to check. Next time it quits you can check both and have a base for what you are checking. This will be a huge help in knowing where to start when it fails.

 

[Midnight]

I will definitely check the connections at the coil to see if they are solid. Not sure what that one lead is. it is not a tachometer, the care does not have one. half to do some digging to see where it goes. As far as the ticking at normal temps, it is hard to tell, while driving that car has so many rattles and other noises going on.
There is a exhaust leak somewhere, I am assuming it is at the muffler, but it has not really been a high priority for me, but it is on the list.

Not sure what kind of oil it is. It is actually cheaper to take it get the oil changed than do it myself. But i will look into additives. see if that helps with the lifters.

it has been a process, trying to figure out the reason for the stalling, try different things here and there, It just seems that it would be much easier to diagnose a problem by making a non running car run, rather than making a running car, non-running.

Thanks for all your input.

 

[DirtDonk]

When you have the oil changed, do you ask the place if they are using what has basically become a specialty type oil for older engines?
Not just "high-mileage" stuff, but oil with the right stuff already in it.
If not and they don't have access to it, then I would definitely be putting the ZDDP additives in at each change.

That's separate from the other additives designed to clean things up inside of course.

 

[Dne007]

Totally agree!

, It just seems that it would be much easier to diagnose a problem by making a non running car run, rather than making a running car, non-running.

 

[Midnight]

Revisiting this issue again, at least the random dying part. Since my last post I have had a couple random stalls, had the bronco towed home and after a few days it would start no problem. Drove it to a local mechanic I trust and he thought it might be the coil overheating and then failing. Replaced with a fancy pigtronix coil. no problems until last week, another random stall. This time had it towed directly to a repair shop. He ran all the tests, said ignition was fine, Carb was getting fuel, but it looks like it is flooding. so now the suggestion is to rebuild the carb, which he does not do, and I don't trust myself with all those little parts.
Which leads me to....should I just switch the truck over to EFI? After looking around the forum, there seems to be a lot of contradicting opinions.
So I thought i would ask for some more opinions to muddy the water more. thoughts?

 

[DirtDonk]

...should I just switch the truck over to EFI? After looking around the forum, there seems to be a lot of contradicting opinions.

Of course! That's because, while EFI is generally "better" than a carb, it's a whole new set of problems waiting to rear their ugly heads!
I would NEVER recommend changing to EFI to avoid cleaning a carburetor. Needing a $15 rebuild kit and a screwdriver and maybe a couple of other tools, does not equal spending thousands of dollars (multiple thousands if you have to have all the work done by someone else), much time, and then much more time diagnosing new problems.
Try to expand your mechanical knowledge first...

But if you're just not that mechanically inclined in general, and don't really have access to tools much more than household stuff like a hammer and big screwdriver, and maybe don't even have a workbench at home (lots of people don't), then even still, having someone rebuild a carburetor is money ahead.
But have it rebuilt. Do NOT have it swapped out for a cheap imported carb. Find someone that can actually do it.

But even before that, you may still be throwing good money after bad, since the mechanic sounds like they're just guessing like the rest of us at this point. Yes, they're guessing from a much more edumacated level, but still guessing until it's actually fixed.
When it died this last time, did you note whether the tachometer needle just dropped like a rock while you were still rolling? Or did it slowly go to zero? Or did you not happen to notice?
Or maybe you were sitting still, still?

When mine had intermittent die-off events, at least I was able to determine right away it was an ignition problem. Still took me a long time to finally just dig into the harness and find a splice had failed where I had installed new wires to a new style ignition. Water got into it and corroded the conductors inside the butt-splice. Darn thing fought me for months.

So do you have a way to post up some images of the area under your hood? We won't be able to see most faults, but we might see some non-original stuff that might be causing you trouble.

Good luck.

Paul

 

[Dne007]

HI! I'm still around

I've gotten incredibly good at overhauling Edelbrock carburetors, but a Holley isn't my thing. So, what do you have for a carburetor? I had a lot of trash in my tank that I apparently didn't get out wound up with a new tank, filters, overhauled the carb. All is well.
dne'

 

[Oldtimer]

I went thru a random stall season in my carbed Bronco.
Took a while, but finally determined the Run contact in ignition switch had worn down enough that it would occasionally open and stop engine.

 

[m_m70]

When it died this last time, did you note whether the tachometer needle just dropped like a rock while you were still rolling? Or did it slowly go to zero? Or did you not happen to notice?
Or maybe you were sitting still, still?

Great question but I don't think he has a tach. It would be nice to know the circumstances when it's stalling though. Cruising? Accelerating from a stop, coming to a stop??

This time had it towed directly to a repair shop. He ran all the tests, said ignition was fine, Carb was getting fuel, but it looks like it is flooding. so now the suggestion is to rebuild the carb, which he does not do, and I don't trust myself with all those little parts.

Concerns me that the mechanic can diagnose flooding but does not/can't rebuild.

But if you're just not that mechanically inclined in general, and don't really have access to tools much more than household stuff like a hammer and big screwdriver, and maybe don't even have a workbench at home (lots of people don't), then even still, having someone rebuild a carburetor is money ahead.
But have it rebuilt. Do NOT have it swapped out for a cheap imported carb. Find someone that can actually do it.

This!!!^^^^^^^ is the best advice.

Which leads me to....should I just switch the truck over to EFI?

I would say a big no. You're looking at thousands of dollars to "maybe" solve an issue that hasn't been proven to be "the" issue (if that makes sense).

So happens when it stalls and you try to re-start it?? Do you smell gas?? Does it seem like it wants to start?? Does it turn over at all??

 

[Midnight]

Of course! That's because, while EFI is generally "better" than a carb, it's a whole new set of problems waiting to rear their ugly heads!
I would NEVER recommend changing to EFI to avoid cleaning a carburetor. Needing a $15 rebuild kit and a screwdriver and maybe a couple of other tools, does not equal spending thousands of dollars (multiple thousands if you have to have all the work done by someone else), much time, and then much more time diagnosing new problems.
Try to expand your mechanical knowledge first...

But if you're just not that mechanically inclined in general, and don't really have access to tools much more than household stuff like a hammer and big screwdriver, and maybe don't even have a workbench at home (lots of people don't), then even still, having someone rebuild a carburetor is money ahead.
But have it rebuilt. Do NOT have it swapped out for a cheap imported carb. Find someone that can actually do it.

But even before that, you may still be throwing good money after bad, since the mechanic sounds like they're just guessing like the rest of us at this point. Yes, they're guessing from a much more edumacated level, but still guessing until it's actually fixed.
When it died this last time, did you note whether the tachometer needle just dropped like a rock while you were still rolling? Or did it slowly go to zero? Or did you not happen to notice?
Or maybe you were sitting still, still?

When mine had intermittent die-off events, at least I was able to determine right away it was an ignition problem. Still took me a long time to finally just dig into the harness and find a splice had failed where I had installed new wires to a new style ignition. Water got into it and corroded the conductors inside the butt-splice. Darn thing fought me for months.

So do you have a way to post up some images of the area under your hood? We won't be able to see most faults, but we might see some non-original stuff that might be causing you trouble.

Good luck.

Paul

I don't have a Tach, so I can not see if the rpms are dropping or not, but it does see like most of the time that it happens the car is slowing down. (I am usually coming to an intersection) It is not that I am not that mechanically inclined, I just know my limits, and when it comes to all the pins and needles in the carb, I just don't trust myself. The carb was cleaned/rebuilt about 8 years ago, and I think that fixed the problem for a few years. after that I focused on electrical, after rulling most of that out, I am back at fuel. Since the car runs beutifully when running, and the carb is getting gas, I am back at the carb situation.
As far a pictures, I posted some videos in the orignal post. so you can get a good view of the engine and hear it running.

 

[Midnight]

I went thru a random stall season in my carbed Bronco.
Took a while, but finally determined the Run contact in ignition switch had worn down enough that it would occasionally open and stop engine.

interesting, I will have to look into that, I have had some issues with the ignition switch, (guages and lights not working, but car is running. ) definitly worth looking into, thanks

 

[Timmy390]

Get a cheap tach. Easy install......Battery pos, batter neg and wire to the neg side of coil. easy peasy lemon squeezy

You can't tune a carb without a tach and a vacuum gauge.

Idle RPM is critical when you have a stalling issue when coming to a stop.

Tim

 

[Midnight]

HI! I'm still around

I've gotten incredibly good at overhauling Edelbrock carburetors, but a Holley isn't my thing. So, what do you have for a carburetor? I had a lot of trash in my tank that I apparently didn't get out wound up with a new tank, filters, overhauled the carb. All is well.
dne'

It is the stock Motorcraft carb, nothing fancy. I tried rebuilding about 9 years ago, just don't trust myself with all the little pins and other little parts. basically just switched out a lot of gaskets, then called it a day. Then and had a profesional do it. Most of the fuel system has been replaced, pump, filter a lot of tubing, over the years. I am pretty confident that the problems lies somewhere in the carb or intake manifold. Then again I was pretty confident it was electrical about 6 months ago

 

[Midnight]

Great question but I don't think he has a tach. It would be nice to know the circumstances when it's stalling though. Cruising? Accelerating from a stop, coming to a stop??


Concerns me that the mechanic can diagnose flooding but does not/can't rebuild.


This!!!^^^^^^^ is the best advice.


I would say a big no. You're looking at thousands of dollars to "maybe" solve an issue that hasn't been proven to be "the" issue (if that makes sense).

So happens when it stalls and you try to re-start it?? Do you smell gas?? Does it seem like it wants to start?? Does it turn over at all??

basically I rolling to a stop and then the car feels like it is running out of gas, then dies. Pretty much a drop to zero RPMS in about 3 seconds. When trying to restart Gas is going to the carb, in fact so much it floods and gas comes out the side. Which led me to think it was an ignition thing, but the plugs are getting spark, so back to the carb flooding issue. Also the fact that after leaving it alone for a few days it starts right up with out a problem, to me at least reinforces the flooding/gunked up carb theory.
the cost of EFI is the big reason not too, I agree, I feel like at this point I am just throwing darts at the board, filters, pumps, tubing, coil, Electronic iginitino, etc....and EFI is an expensive dart. I am trying to figure out how long it took for the issue to start again after the last rebuild which was in 2016 or 2017.

 

[m_m70]

I have changed fuel filters, pumps, cleaned hoses, put in a Pigtonix electronic ignition and other various items.

Were you having the stalling out problems before you put the Pertronix ignition in?? That system is known for problems if the resistor wire is still being used and the module is not getting 12v.

I have had some issues with the ignition switch, (guages and lights not working, but car is running. )

I'd just replace that since you know it has issues and should be replaced anyway. Could very well be part of the intermittent issues.