71' won't start: fuel or ignition problem, HELP!

[351Boss]

So I bought my first bronco about a month or so ago. I have been reading this forum a lot and using it as a guideline for my projects. I am still in the process of learning and seeing what the PO did as compared to how it should be done. Now my inexperience is getting the best of me and I need some help, please!! The basic low down up front of what I am working with, 1971 Bronco w/ Boss 351, 351C w/ 4barrell Holley Carbs

It started after I changed the motor mounts. I made a really rookie mistake (which I admit I am a rookie). When I lifted the engine to put the motor mounts on, I leaned the engine back on the wiring harness. I managed to crush a few wires in half, the fuel pump wire, primary wire, and the left turn signal wire. This is where the snowball effect started. Not knowing that the wires were crushed, the vehicle started and I went on home (about 4 miles). Next day drove it about 9 miles then parked it. That following day I went to drive her and it wouldn’t start.

After some peaking around I realize that that the carb is not getting any gas. I check the fuel lines and pump; the metal fuel line from the pump to carb is kinked pretty badly. I would say that it was kinked so only about 20% of the fuel was allowed to get through the line. So I just replaced the fuel pump, fuel filter, and fuel lines from the pump to the filter. This is when I noticed the crushed wiring harness, soldered and shrink wrapped them back together. Matched it up wire to wire so I didn’t cross any wires, now its time to try and fire it up. With a little started fluid to the carbs I got it cranked. It was running for about 30 seconds or so. My whole problem was not getting gas to the carbs. So I have my buddy press the pedal a little so I can look at the carb to see what its doing. From what I saw it was spraying gas in the front 2 barrels, not the back two. Then my buddy hit the gas pretty hard once to keep it alive. That’s when it backfired out of the carb and died. This is where I am stuck. Since then I haven’t been able to get it back up. From what I’ve been reading when it backfires like that it’s either the timing or a burnt valve. Now the dizzy did jump about 180*, I found TDC and pointed it back to #1 spot.

I replaced the plugs (autolites). I also found out that I blew the ignition coil accell 4180C. So I put the stock coil back on and it acted like it wanted to start. No blown fuses either. After another can of starter fluid and some hesitation from the engine I was able to get it started (ran really crappy) and then it died again. It was only staying cranked off of the starter fluid. I didn’t notice any gas being sprayed into the carbs. When I installed the fuel pump I put it in at angle and as I put the bottom nut on I had to compress the pump to get it bolted down. Is it possible I installed the fuel pump wrong? What else could be my problem?

My timing has been off since I bought it, but not bad enough to where it wouldn’t start. Just a extra turn or so when it cuts off. It was running rich, and that was with the kinked fuel line. I am thinking that since I replaced the fuel lines allowing a lot more fuel through it really threw off the timing even more. The timing issues then caused the dizzy to popped 180* off, the back fire through the carb, and the blown ignition coil. Does that sound right? What else could be broken? Thanks for reading all of this! I appreciate any help in advance!!!

 

[BRONCROB]

If your "dizzy" moved any at all you have problems.Did you mean the rotor? Never heard of a backfire blowing a coil either.MIGHT BE A GOOD IDEA TO GET A MECHANIC TO CHECK IT OUT.

 

[70_Steve]

Now the dizzy did jump about 180*, I found TDC and pointed it back to #1 spot.

What, exactly, does " Now the dizzy did jump about 180* " mean????:?

If you have to reinstall the distributor, just finding TDC isn't good enough. Being a 4 stroke engine, the crankshaft makes two revolutions for every one revolution of the rotor in the distributor.

So... When you reinstall the distributor, you have to install it (with the rotor pointing to the #1 sparkplug wire) with the engine at TDC on the compression stroke!

To find TDC on the compression stroke, you might want to pull all the spark plugs, to make the engine easier to turn over with a socket and ratchet (the way I do it...). Put socket and ratchet on the harmonic balancer bolt, put a finger over the #1 cylinder spark plug hole, and turn the engine over. When there's so much pressure coming out of the spark plug hole that you can't possibly block it off, you've found the compression stroke. Then just continue to turn the engine unti the timing marks lines up with the indicator. Drop in the distributor so the rotor winds up pointing to the #1 spark plug wire on the distributor cap. I make a mark (Magic marker) on the inside of the distributor that aligns with that #1 spark plug location. Makes getting the rotor aligned that much easier.

 

[351Boss]

If your "dizzy" moved any at all you have problems.Did you mean the rotor? Never heard of a backfire blowing a coil either.MIGHT BE A GOOD IDEA TO GET A MECHANIC TO CHECK IT OUT.

Yeah I'm sorry I got my words mixed up. The rotor was off, not the dizzy. Yeah the dizzy is not moving, it has been seized since I got it. I'm trying to get it free right now with acetone & transmission fluid. Nothing else had worked yet to get it free. When that is done I can adjust my timing..after I get it to crank up.

 

[351Boss]

What, exactly, does " Now the dizzy did jump about 180* " mean????:?

If you have to reinstall the distributor, just finding TDC isn't good enough. Being a 4 stroke engine, the crankshaft makes two revolutions for every one revolution of the rotor in the distributor.

So... When you reinstall the distributor, you have to install it (with the rotor pointing to the #1 sparkplug wire) with the engine at TDC on the compression stroke!

To find TDC on the compression stroke, you might want to pull all the spark plugs, to make the engine easier to turn over with a socket and ratchet (the way I do it...). Put socket and ratchet on the harmonic balancer bolt, put a finger over the #1 cylinder spark plug hole, and turn the engine over. When there's so much pressure coming out of the spark plug hole that you can't possibly block it off, you've found the compression stroke. Then just continue to turn the engine unti the timing marks lines up with the indicator. Drop in the distributor so the rotor winds up pointing to the #1 spark plug wire on the distributor cap. I make a mark (Magic marker) on the inside of the distributor that aligns with that #1 spark plug location. Makes getting the rotor aligned that much easier.

Thanks for the info! I plan on replacing the distributor in a month or so. I'm pretty sure you just saved me headache!

 

[351Boss]

I am going to switch to an electric fuel pump. The mechanical pump is pulling but I think electric would suit me better and a little upgrade. Hopefully that will help. Rechecked my ignition coil, turn out it is still good. But for now I am going to stick with the stock coil.

Is it possible that my fuel sending unit went out? Maybe when the fuel pump wire was crushed??

 

[broncnaz]

I think you need some help from someone a little more familar with engines and how stuff works. Not sure on what model of holley carb you have but only double pumper carbs will squirt fuel into the secondary side of the carb and even then you have to push the throttle past half way. Another question do you have one carb or 2 carbs? As you said carbs.

If the rotor was not on correctly or popped off then you may have damaged it or the cap. You might consider replacing them as damage could be causing missfire/crossfiring. Also do you have points or electronic igintion? If points they may need adjusting or replacement. As the gap changes it causes the timing to change.

I really wouldnt be using starting fluid to start your engine with. You can do a lot of damage to a engine with that stuff. Id suggest pouring some gas into the carbs fuel bowl vent to fill it up. That should allow the engine to run for a minute or two. Which should allow the fuel pump to start working.
Fuel sending units can go out but not because the fuel pump wire was crushed. its a seperate wire. If the gauge is not working just put say 5 gal in the tank and you will know you have gas.
Running rich will not throw the timing off nor will A backfire thru the carb. Unless the timing chain jumped a tooth. but thats not very likely to happen. A back fire wont cause the igintion coil to go bad either.

 

[351Boss]

Point taken on the starter fluid! I didn't know that. It's only 1 carb Holley 4777, not sure why I said carbs. I don't have an electronic ignition I have points. This is the second time the rotor has been pointing to the wrong spot. Every time I move it back it seems solid and not loose. I was going to replace the distributor in a few months with a ready to go unit. Looks like I should go ahead with that and get it sooner!

 

[BRONCROB]

No offence,but you should get a mechanic to check your bronco out.It may save you a lot of cash,headaches, and maybe an engine.You may only have a simple problem that can easily be corrected.

 

[broncnaz]

Well Id check the points gap and make wsure the rotor has a little nub on the inside so it doesnt spin. But like I said maybe it would be a good idea to change the cap and rotor. they are fairly cheap. Of course if you pull the trigger on a new dizzy then disreguard.
I just wanted to be sure on the carb thing. That should be a double pumper so it should have squirters on the secondary but like I said it wont squirt back there until the secondary throttle blades start to open. But I wouldnt worry much about the secondary side until you get the engine running decent. The carb will work but its usually not the first choice for a 4x4.

 

[jw0747]

No offence,but you should get a mechanic to check your bronco out.It may save you a lot of cash,headaches, and maybe an engine.You may only have a simple problem that can easily be corrected.

x2...it kinda sounds like some of the things you're doing to get it running are maybe making it worse than it really is. Sounds to me that it's probably a timing/ignition problem

 

[DirtDonk]

For some reason, stuck distributor bodies are a very common issue with the 335 series engines. I have no idea why they would be any more prone to it than others, but even here in CA mine was stuck pretty good when I bought my '79.

I've walked through it with many a member over on projectbronco.com and the more active 7879blueovalbronco.com.
Since they came stock with the 351M engines, it comes up a lot over there.

Basically though, especially for a HI truck, your best bet is to keep soaking the joint with penetrating lubricant of some time or another. Then maybe some of that Locktite "Freeze-Off" stuff. Then some heat!

Unfortunately, I know several who have literally had to beat theirs into submission with bigger and bigger hammers until they actually broke the distributor.
This is obviously not the most desirable outcome, as the likelihood of getting chunks of aluminum down in the engine go up exponentially, as you have to chip away at what's left.

Good luck on it all. But especially that stuck distributor!

Paul

 

[351Boss]

I believe I am just going to replace the whole dizzy and bust out my new timing gun. I've been soaking the dizzy, got a weekend project now. Then I will take the heat gun & mallet to it. Hopefully that will get it running again. I'll keep y'all updated, thanks for all the help!!