Bronco Not Starting (Firing)

[lucky7_1080]

Not to sound like "that guy", but what you are saying here doesn't quite jive. How are you turning the crankshaft ?

W/ a 15/16" socket and extension directly on the crankshaft, tranny in neutral.

What is your reference point?

TDC (0deg.) is marked well on my balancer, so it's been easy to see when I'm all lined up.

If its really that inconsistent, then you might have an extremely loose timing chain that's jumping on the gears. I don't believe that is the fact here based on the fact that it runs at all.

To add a bit more clarity on the "running". To get it to fire at all I have to keep the starter engaged while its firing and bury the pedal as I let off the key. This wasn't really clear from my videos. I don't believe all cylinders are firing (also not clear from the video).

You mentioned earlier that fuel is coming from the venturis at WOT (I assume while cranking) If that is a fact, then your float level is way too high as no fuel should be seen there until high rpm.

Float is set parallel to the top of the bowl, down 1.3cm (a bit lower than the OEM float by a mm). I pulled the cover back off and bowl is half full. I don't believe that the carb is the issue.

Id go back to the float level until that is proven correct.
You can check the timing chain wear by lining up the 0 deg mark on the crankshaft damper with the pointer, (The rotor should point at 1 or 6 depending on which rotation you are on. (It takes 2 crank rotations to compete the 4 stroke cycle)0.
Next move the crank back and forth with a ratchet and 15\16' socket on a 6" extension. Note how far you have to rotate the crank each way before the rotor starts to move.
This is called timing chain deflection and shouldn't be more than 8 to 12 deg. (its marked on the damper there, so easy to read. Plus if your back and forth measurement is consistent, the chain and dist drive gears are not jumping.

Chain deflection is 20 degrees plus. The play is inconsistent depending on where I am with the full crank rotatation.

All that being said, I'd still stay on that float level until you are positive it is correct. It makes the most sense based on the information we have.
It can look suspicious though as you've been through the carb and the symptom appears to be the same. I believe your initial failure was a bad float or needle and seat and , if the float is set too high, the problem is the same.
Hope that helps.
Good luck
Cheers

I haven't pulled the distributor yet and am EXTREMELY nervous to do so for fear of the oil pump shaft dropping into the pan. After more discussion with local mechanics and on the forums, do you all believe that there is the possibility of the pump gears seizing? I've been researching all the reasons why the distro rotor wouldn't spin 180. When I think back to the initial event I consider what would have changed when it fired normally on the flat, and why I couldn't get it to fire on the slope.

I've ordered the parts necessary to replace the gears, chain, water pump, etc. as I've performed this service in the past. It's unclear whether gears and chain have ever been done, but water pump is at least 20 years old, as I've already had to swap at least one press-in fitting as it rusted in half.

Thanks all.

 

[lynchsg]

Pump driveshaft can drop when pulling the distributor and fall out of pump engagement if the pump driveshaft retainer is not on the shaft. I had that issue once.
Pump gears failing is very rare, at least in my experience.
Depending on how many miles are on the engine, and you probably don't want to see this, you may need to go through the engine and rebuild it.

 

[L\Bronco]

W/ a 15/16" socket and extension directly on the crankshaft, tranny in neutral.



TDC (0deg.) is marked well on my balancer, so it's been easy to see when I'm all lined up.



To add a bit more clarity on the "running". To get it to fire at all I have to keep the starter engaged while its firing and bury the pedal as I let off the key. This wasn't really clear from my videos. I don't believe all cylinders are firing (also not clear from the video).



Float is set parallel to the top of the bowl, down 1.3cm (a bit lower than the OEM float by a mm). I pulled the cover back off and bowl is half full. I don't believe that the carb is the issue.



Chain deflection is 20 degrees plus. The play is inconsistent depending on where I am with the full crank rotatation.



I haven't pulled the distributor yet and am EXTREMELY nervous to do so for fear of the oil pump shaft dropping into the pan. After more discussion with local mechanics and on the forums, do you all believe that there is the possibility of the pump gears seizing? I've been researching all the reasons why the distro rotor wouldn't spin 180. When I think back to the initial event I consider what would have changed when it fired normally on the flat, and why I couldn't get it to fire on the slope.

I've ordered the parts necessary to replace the gears, chain, water pump, etc. as I've performed this service in the past. It's unclear whether gears and chain have ever been done, but water pump is at least 20 years old, as I've already had to swap at least one press-in fitting as it rusted in half.

Thanks all.

Thanks for the clarity
the pump drive is held in the block by a tinnerman nut just below the block surface near the main cap. the only way they can fall out is if the last guy took it off. I've had it before, but I definitely wasn't the first one in there.
oil pumps do seize on those old fords occasionally. Every one I've seen twists the hex shaft off below the distributor, but they always run fine, they just lose oil pressure
It certainly sounds like your cam timing is dancing around on you. very weird, but not impossible.
The easiest way to verify that I can think of is to pop off the left valve cover, turn the engine by hand until cyl#1's valves are in the rock position, (exh valve just closing, intake just opening, but lined up at the same height.) Does that make sense? When you get there, the timing pointer should be at 0. You can also check that #1 is at TDC through the plug hole with a long tool for turning Spiraled fasteners, (I'd pick a long blade type just for the censors) But the timing marks should line up, unless the balancer has slipped as well.
Hope that helps
Good luck
Cheers

 

[lucky7_1080]

Hi folks. Quick update and some new questions for the group. I finally had some good weather today so was able to pull the front end off to inspect the gears and chain. I did not pull the distributor. I also did not follow the guidance re: pulling the passenger valve cover to confirm compression stroke. Considering how out of whack the rotor was, I anticipated being way out of time. I rotated the crank to TDC when the rotor was as close to Cylinder 1 firing position as possible. Here's what I was left with when I pulled the cover:



You'll note that the timing mark for the cam gear is at about 2:00, or ~120 deg (or 240 deg.) off from where I should be on the cam. You can also see how worn the cam teeth are. Unless someone can confirm that 79's had neoprene cam gears, I imagine this is the original gear. Or even worse, this was a neoprene coated gear and all of the neoprene has shredded off and is settled down in the pan. The teeth were so worn, and chain so loose that I could almost jump a tooth by hand. Here's a quick video:

Timing Chain Play

I ordered some new gears, a new water pump, stat, and gasket kit and am set for a re-install post cleanup. Couple important questions:

1) Now that I've confirmed that the cam and crank are not in time, what's the best way to sync everything back up? Before I pull the gears, should I rotate the crank around until the timing mark on the cam gear is at 6:00, then pull the gears and chain and rotate the crank until its back at TDC? Would love some guidance here on how to get it synced back up, and preferably without having to pull a valve cover.

2) I rented a timing gear puller but it doesnt seem to fit or work with my truck. Any guidance on the best way to pull this gearset? And best recs on installing the new gears? I assume that the gas pump eccentric and harmonic balancer will pull everything back into alignment?

3) The harmonic balancer is showing some signs of wear. There's a rubber? seal between an inner and outer ring that's starting to fail due most likely to oil impregmentation. Would you all recommend that I replace the balancer? (You'll also note the failure of either the main seal or the front oil pan seal or both.) Here's a photo:



4) I pulled the front two (1/2") bolts from the oil pan and loosened the next two (7/16") bolts on each side. This didn't really allow the pan to drop. When I pulled the timing chain cover off, the lower portion was still a tight fit. The gasket did remain on the cover however. Any guidance on creating the clearance needed to properly set the timing chain cover and front oil pan seal during reinstallation?

Thanks all for the help!

L7

 

[lucky7_1080]

Additional update. I did a search for the cam gear part. no. listed on my gear and couldn't find that exact gear, but did find this one on ebay listed for the '79 model year. You'll note the hole pattern is very similar and it is in fact neoprene coated. I suspect that mine was as well at one point and I've lost all the coating. Is it necessary to drop the pan and clean all these bits out? Will this clog (or has this potentially clogged) the filter screen on the oil pump?

 

[lynchsg]

Gear set and chain is supposed to slide off as a set. May need some penetrating oil and a little "help" with a screwdriver or small pry bar?
The cam and crank should be aligned as shown in the picture at assembly. Triangle mark on camshaft sprocket aligning (gear mark on botton towards crankshaft) with crankshaft keyway or mark on crankshaft pointing up as in your picture.

 

[lynchsg]

Another possible issue here is with the cam timing so off to the crank in your picture. There could be bent pushrods or valves. Hopefully the hydraulic lifters absorbed the bad valve timing to the pistons?

 

[lynchsg]

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[lynchsg]

To get the cam in the correct relationship with the crank, you need to pull both valve covers. Then remove all the rocker arms , noting where each rocker arm came from. Then you can turn the cam without any issue of valve to piston interference.
With the rocker arms removed, I would pull each pushrod, again noting where each came from, and roll the pushrods on a flat surface to see if any of them are bent.
After putting everything back together, you should turn the crankshaft a couple of times to verify if any valves might be stuck (which usually means they are bent).
Sometimes if you have a collapsed hydraulic lifter a valve may not move much.

 

[Tiha]

At least you found it. That is great news.

Just move the cam gear back pointing where it needs to go. Don't have to get too fancy getting it lined up.

Not sure if this is an interference engine, but I doubt it. So not likely there is valve damage.

Just line up the timing marks and install the new gears and chain.

Worst case problem would be the distributor is 180 degrees off. Not a big deal.

I would leave the balancer. Yes it is getting bad. But depending on how much you drive it, probably has a lot of years left in it.

 

[lucky7_1080]

At least you found it. That is great news.

Just move the cam gear back pointing where it needs to go. Don't have to get too fancy getting it lined up.

Thanks. Does the method I outlined in prior post make sense? Rotate cam with both gears still on, pull gears and rotate crank until Tdc?

Not sure if this is an interference engine, but I doubt it. So not likely there is valve damage.

any way to confirm?

Just line up the timing marks and install the new gears and chain.

Worst case problem would be the distributor is 180 degrees off. Not a big deal.

wouldn’t I know this is the case based on rotor position when gears aligned properly? Any way to correct this?

I would leave the balancer. Yes it is getting bad. But depending on how much you drive it, probably has a lot of years left in it.

cool thanks.

 

[wyo58]

I'm pretty sure as well it is not an interference engine as well. I am also pretty sure you would have heard that while you were trying to start it. Line the crank up like the picture and it looks like your there right now. You are probably going to have to loosen up all the rocker arms enough to be able to spin the cam by hand (use the new cam gear your getting for more torq, no chain). once you have the cam lined up where the picture shows it to be, slide the gears off and install the chain on the gears and go back on the two shafts. Do not replace that nylon toothed animal with another one, all steel. Ford did that for engine noise and it was a disaster as you can see. Usually the wear on that isnt in chuncks but fairly fine particles that are more than likely already mostly in your past oil filters, either way they have already done any damage that they could ( usually none). The crank gear can be tough to get off as a film builds up on the crank. Scotch brite pads and some elbow grease will get it off enough to slide off easily. The balancer is deffo starting to come apart. You can use it again but always keep in mind if it does come apart while running some RPM could cause some damage up front there, belts, hoses water pump, radiator. Tough call could last a long time or if you have my luck it takes all the fore mentioned. I believe if you leave the distributor alone it should line right back up, however it might also not let you spin the cam back to the correct position for timing the two shafts, so you might have to remove it anyway. Try to leave it and see if you can spin it. I am somewhat surprised that they used that POS cam gear this early and on a modified block, I always thought they were on the windsor blocks only, but you proved that wrong. Great job btw, your doing great so far. Patients and stick to it and you will be up and running in no time! Also if you do use the old balancer you will need to get a seal sleave (speedy sleave) that installs over the seal journal, that one is going to leak even with a new seal installed.

 

[lynchsg]

Yes, my bad. I have a high performance Windsor 351 engine in my '82 and forgot the smog Modified 351s are not a valve interference engine.
wyo58's direction is good, except I think he meant to say DO use steel gears...

 

[lynchsg]

Oh and one more thing, run some emery cloth on the seal riding surface of your harmonic balancer to take any rough edges off. That way a new front seal may not leak prematurely.

 

[johnnyreb]

View attachment 30978

To make sure you are getting the right amount of power (voltage) out of the coil---INTO the distributor at ALL times. Couldn,t a person put a spark plug tester and watch the gauge or brightness of the spark in the tester--to see if it would change any or not?

 

[wyo58]

To make sure you are getting the right amount of power (voltage) out of the coil---INTO the distributor at ALL times. Couldn,t a person put a spark plug tester and watch the gauge or brightness of the spark in the tester--to see if it would change any or not?

Never thought of it like that but I suppose you could put that in line of the coil output wire to the distributor cap. It would pulse every time it collapsed and fired. But you would only want to do it for testing not all the time as it would decrease total output? Oil filled coils of that era only put out so much spark. The later versions called "e-core" coils, put out a lot more voltage and could jump to ground before the cap. So again only for testing.

 

[johnnyreb]

Never thought of it like that but I suppose you could put that in line of the coil output wire to the distributor cap. It would pulse every time it collapsed and fired. But you would only want to do it for testing not all the time as it would decrease total output? Oil filled coils of that era only put out so much spark. The later versions called "e-core" coils, put out a lot more voltage and could jump to ground before the cap. So again only for testing.

 

[johnnyreb]

Another thing that you might want to checkout really good is the cap--with a magnifi glass. Alot of this junk made in China can throw you off. Check your parts really good. Their is alot of bootleg parts on the market .That look American made ,but is not. Check the plug wires. Especially where they go on the plug. Some are off a good bit.

 

[johnnyreb]

Hi folks. Quick update and some new questions for the group. I finally had some good weather today so was able to pull the front end off to inspect the gears and chain. I did not pull the distributor. I also did not follow the guidance re: pulling the passenger valve cover to confirm compression stroke. Considering how out of whack the rotor was, I anticipated being way out of time. I rotated the crank to TDC when the rotor was as close to Cylinder 1 firing position as possible. Here's what I was left with when I pulled the cover:

View attachment 31048

You'll note that the timing mark for the cam gear is at about 2:00, or ~120 deg (or 240 deg.) off from where I should be on the cam. You can also see how worn the cam teeth are. Unless someone can confirm that 79's had neoprene cam gears, I imagine this is the original gear. Or even worse, this was a neoprene coated gear and all of the neoprene has shredded off and is settled down in the pan. The teeth were so worn, and chain so loose that I could almost jump a tooth by hand. Here's a quick video:

Timing Chain Play

I ordered some new gears, a new water pump, stat, and gasket kit and am set for a re-install post cleanup. Couple important questions:

1) Now that I've confirmed that the cam and crank are not in time, what's the best way to sync everything back up? Before I pull the gears, should I rotate the crank around until the timing mark on the cam gear is at 6:00, then pull the gears and chain and rotate the crank until its back at TDC? Would love some guidance here on how to get it synced back up, and preferably without having to pull a valve cover.

2) I rented a timing gear puller but it doesnt seem to fit or work with my truck. Any guidance on the best way to pull this gearset? And best recs on installing the new gears? I assume that the gas pump eccentric and harmonic balancer will pull everything back into alignment?

3) The harmonic balancer is showing some signs of wear. There's a rubber? seal between an inner and outer ring that's starting to fail due most likely to oil impregmentation. Would you all recommend that I replace the balancer? (You'll also note the failure of either the main seal or the front oil pan seal or both.) Here's a photo:

View attachment 31049

4) I pulled the front two (1/2") bolts from the oil pan and loosened the next two (7/16") bolts on each side. This didn't really allow the pan to drop. When I pulled the timing chain cover off, the lower portion was still a tight fit. The gasket did remain on the cover however. Any guidance on creating the clearance needed to properly set the timing chain cover and front oil pan seal during reinstallation?

Thanks all for the help!

L7

the chain and gears need replaced. The plastic is wore off of yours. You can get the steel teeth ones.

 

[Tiha]

Thanks. Does the method I outlined in prior post make sense? Rotate cam with both gears still on, pull gears and rotate crank until Tdc?


wouldn’t I know this is the case based on rotor position when gears aligned properly? Any way to correct this?

Your thought process is fine. I would imagine you are probably done by now anyway.

The most important thing is that the timing marks are lined up when you put the new set on. However you get there is not a big deal but your plan is sound.

As far as a puller. Not sure I have ever used one. Can't think of a gear ever being that tight. Sometimes you take a hammer and a punch and beat on them to loosen them up a little. There is some gunk build up that always sticks them a little. The crank gear especially can be a little tight, but those gears are junk now anyway. so you can get a little rough with them.
Pry on them a little. Get them started.