Hello I have 1976 highboy with a 360 in it and have been having some problems as far as starting and staying running. I have replaced fuel pump fuel lines, put a new carburetor on a year ago. I had the old unilite points distributor on it before I replaced it with the hei distributor and it would start up but only with a jump so I was told the hei distributor would help and fix that. I put the distributor in and i finally got it to start it ran pretty good. I took it for a test drive brought it back and I didnt even make it up the hill before it died. finally got it back in the driveway to work on it and couldnt get it start back up. I then went and got new spark plug wires the spark plugs are fairly new. I then made 100% sure that it was top dead center and set the plug wires to where it started on #1. It still wouldnt start, but will back fire through the carburetor and spit fuel out of it all over the place. It will also sometimes backfire through the exhaust. I have checked pretty much everything but if there is something that I am forgetting I would really like the advice. Thanks in advance

 

These are random things that come to mind, in no particular order and maybe not even related.

I've had a bad condenser cause backfiring and flames out both ends.

A neighbor swore up and down he had the firing order correct, it took me a couple hours to convince him to try a different order and it started right up.

Timing chain jumped a tooth can cause all sorts of trouble. Especially if you still have the plastic tooth crank gear.

I regularly install the distributor 180 out. In fact, so often that sometimes, I'll just pull it right back out and turn it 180. Usually to find that I had it right the first time.

Spiting fuel makes me think there is way too much fuel in the manifold but then the plugs would be wet.

Michael

 

I dont think I jumped the timing gear because the marks on the harmonic balancer line up perfectly with top dead center.

I have tried 2 different carburetors because I thought when it spits gas up the carb it could have been the carburetor but I tried my old one and it does the same thing. Could have something to do with the choke on either of the carburetors?

It did start up and run really good then it died before I got in the driveway and now it wont start. I have the firing order going counter clockwise and its on the #1 cylinder so I dont think its 180 off but I could be wrong.

 

If the timing gear jumped, the timing mark and the piston will still be in time but the cam and thus the distributor will be out of time with the crank.

I'm sure there is a way to test for this but am drawing a blank at the moment. When all the teeth fell of my crank gear, the truck started losing power pretty rapidly then coasted to a stop. That was the first time I had it towed home from Military Road. The second time was when the tranny failed last November. I still drive Military but with fingers crossed!
Michael

 

There is absolutely nothing wrong with a stock distributor ignition system, should not be necessary to install a gee-whiz bang ignition system to get it to run well.

Generally, backfire through the carburetor is almost always a timing issue of some sort or another. Firing order, crossfire, distributor installed out of phase, etc.

 

It did start the first time and I dont think it was on top dead center when it first started. If I rearrange the wires to where it does fire but is not on top dead center would this be the cause of it jumping the timing gear?

 

You can check for jumped timing by pulling the valve covers and watching the valves. If it's way off they will be out of sink with the crank and easy to see. If the look good I'd pull the distributor and re run all the plight wires.

 

It's really hard to get it to jump and just to clarify, when I say timing gear, I really mean sprocket and chain. With a new chain and sprockets, there is enough tension that there would have to be a catastrophic jam or back fire to jump the timing but with enough wear, a back fire or some other kick back could cause the chain to skip a tooth.

Ford used nylon on the one of the gears teeth to reduce noise or something like that. With age the nylon gets brittle and that's not really a good thing when you are counting on things happening at a specific time.

As far as TDC goes, I'm assuming that you have somehow checked that the #1 piston is at the top of it's stroke and that the timing mark is lined up at TDC. What you have to remember is that there are two times that the piston will be at the top with the mark lined up. One is on the compression stroke which is what you want, the other is the top of the exhaust stroke.

Are you finding TDC by putting your finger over the spark plug hole while cranking and feeling for the puff of air that indicates it's on the compression stroke? As soon as you can feel the puff of air, you can then pay attention to the timing marks to get it lined up just right. This is a two person job unless you have a remote starter push button or really long arms so you can reach the key to bump it.

You can check for timing chain stretch following this . This works great for old school OHV pushrod engines with chains but I'd be real careful with OHC engines. If I did this on my '76 450SEL, I'd be replacing parts.

Here is a link to a pic that shows the position of the rotor when it's at TDC on the compression stroke.

Michael

 

What do I need to look for when I pull the valve covers off? What do you mean by out of sink and easy to see?

 

Haha I like the really long arms comment. I didn't think about it being on the exhaust stroke. I will check to see if it is on the exhaust stroke or on the top of the compression stroke. Is it possible that the harmonic balancer could be 180 degrees off or upside down? The guy that put this motor in had to replace it with the old one off of my 390 motor which may mean it doesnt line up.

 

Also thanks for the video that will be helpful when I am checking for slack later tonight.

 

I wouldn't think you could put it on incorrectly but the inner and outer parts are connected with rubber and it's been known to slip, causing the timing marks to be inaccurate. Also, I don't know if a 360 uses the same balancer as a 390.

Michael

 

Im not sure either but my buddy looked at it and said the same thing. He didnt think it could be put on wrong either.

 

All I can do is tell you what fixed my crazy back fire through the carb. I had a combination of cheap plug wires that wouldn't seat correctly, a new cheezy Dizzy and a blown out carb mount hole that needed to be re-tapped causing a vacuum issue at the carb base gasket... After I bought some good plug wires, put the old Dizzy back in and tapped the intake manifold hole, put a new carb gasket on, it fired right up, no probs....... and I checked my timing and firing order about a dozen times......

 

Ok I got it up and running found out I was 180 degrees off. set the timing to where it starts extremely good but when I drive it it is really slow and has almost no power. it takes forever to get up to 25 mph. I shut it off when I got back and it acted like it wanted to keep running. It also idles around 1100