x2! :)

Jumping across the points would be way-easier than finding a spark plug
through the distributor cap and all that crap! ...without the condenser. :)

"mountain building" on one or the other of the contacts tells you if the
condenser is too weak or too strong. Too weak could be from a not so
good connection also. Building up on the movable point is from weak
condenser "action".

Man it's been so long since I messed with points I had to look it up in
my book again. Mike mentioning the -real purpose- of the condenser
prompted me to reread it and post it. :)

Alvin in AZ

 

Interesting, I didn't know that either. But like I said I replaced mine. Still getting yellow spark coil output, is there a way of eliminating something from the picture to test if I can get the desired spark from the coil?

This is getting crazy. In my pastlife I was a Mopar man. This problem would have been taken care of simply and easily by changing the ballast resistor on the fire wall. On my old 'cuda I mounted and extra one just below the factory one. On a few occaisions, if it wouldn't start, I would just move the plugs down to the new one and drive off.

I know ford uses a resistor wire, I have check mine for both continuity and resistance, both good.

 

That's what I don't get, you're getting spark (weak or not), fuel and you should have compression.

You're getting spark at the spark plugs which means the distributor is turning and didn't lose it's roll pin or the timing gears broke.

You didn't rotate the distributor (or did you?) to make the engine out of time.

You are jumping the battery so the engine will turn over easily.

Kind of grasping at straws now. Bad gas maybe?

Josh

 

You wouldn't happen to live in Northern Colorado would ya?

Josh

 

No, I don't live in CO. I'm in Michigan.

Im going to double check the distributor #1 cyl to the tdc mark on the crank. But that wont tell me if valve timing is correct. Then I'll be pulling the valve cover to check tdc with valves. The timing gears were replaced only a few weeks ago, by a licenced shop and it did run after that. I hope those didn't crap out already.

But that still wouldn't explain weak spark.

After that I'm going to do a compression check.
Some work today, some tomorrow. I'll post my findings there.

Thanks

 

Sounds like a plan. Bring #1 to TDC while watching valves and observe the rotor on the distributor, it should be pointing at #1 terminal on the cap.

It's possible something came loose. I had an FE engine run like a champ and then one day while driving began running incredibly rough. What happened was the camshaft timing gear pin sheared off.

Another time I went into a restaurant and when I came out the truck wouldn't start no matter what. Took the cap off and cranked the engine over and the rotor didn't rotate. Turned out the roll pin for the distributor gear snapped.

Josh

 

Referring to your question about testing the coil - you were told absolutely right. Measuring the DC resistance of the coil windings doesn't tell you anything about the inductance of the coil, which has a giant factor in the voltage output. The proper way to test the coil would be to look at the frequency response on an oscilloscope (which few people have) or to measure it on an LCR meter (which I can't imagine anyone owning at home). And even then, I have no idea where you'd find the specifications for that other than measuring a known good coil and calling it a ballpark number.

But, the DC resistance test will at least identify obvious stuff. The useful one is the primary winding resistance, because it can give you an idea of the voltage divider created between it and the ballast resistor.

This is really strange. It sounds like you've tested pretty much every possible parameter on a points ignition system, and the numbers sound good. Aside from replacing the condensor. I did have one go bad on me before. I hate to tell people to replace parts randomly, but I don't know what the capacitance should be of a known good condensor, so without going and buying one myself I wouldn't know what number to tell you to look for.

Anyway, good job on troubleshooting this much so far. You're much more patient than most people. I do agree with the above suggestions about checking the valves and making sure the rotor is turning.

Speaking of the rotor, if you take the cap off, hold it upside down, and place the rotor inside as it would sit normally, does it seem reasonable? Does the top of the rotor have plenty of length to make contact? Is the rotor approximately equal to the inner radius of the cap, with just a small gap in between? That gap is just as important as spark plug gap. One time I bought a rotor for my 400, and inside the box was a rotor for a 6 cylinder. The 6-cyl rotor is much shorter, and the motor wouldn't have fired if I had tried to install it.

Why not check the firing order while you're at it.

 

Did you try pulling a spark plug to see if it is fouled?You have been cranking and cranking and cranking and cranking and cranking and probably have fouled out the plugs.when you pull the plugs just do a compression test just to see where you're at.If the plugs are clean and dry(I would personally throw in a new set of good plus since I had them out)try a shot of ether.BE CAREFUL!don't lock the engine up and don't set yourself on fire.I personally crank the engine while giving it little shots of ether.

 

Also did you check the voltage at the coil while you are CRANKING?It should be 12 volts.If you don't have 12 volts check the solenoid terminal first(remember to close the solenoid).When the key is in the run position then you get the 9.6 or so volts at the coil.

 

Answers for all.

WarWagon, Yes I have 12v at coil while cranking. My plugs are pretty carboned up (black) but are in good shape. None the less, I'm goinig to put in a fresh set tomorrow, since I have them all out.

fmc400, Thanks for backing up what I was told, it makes my purchase more justifiable... even though it appears I didn't need it. I sold my O-Scope last year, but I would have needed to retake a class on how to use it! It's been about 20yrs since I used it.

Bullitt390, I removed plugs and did a compression check, all cylinders measure between 130 & 135psi. I hope this is within specs. I moved the crank manually to #1TDC and compared it to the mark on the distributor body I made below the #1 tower. I removed the cap and found that the rotor was about 1/4in. behind the mark. I marked the base of the distributor (just in case) loosened and rotated the distributor to line up the center of the rotor tip with my mark. I put the plugs back in and gave it a try... still nothing. It took the plugs back out (I know double work... I goofed) and removed the valve cover. I put my ratchet on the crank and watched the rocker arms and put finger in plug hole. My distributor coming around to my mark and the valves were closed and my finger was being pushed by the compression. Compression stopped, the valves still closed, timing mark right on the money and so was the rotor. I did this several times, watching the other cylinders as well in the order they fired. All looked good. I took my cap with the wires into the house for a closer inspection.
I found some chaffing on the #5 wire and white powdery corrosion in a cap tower. So while I'm at the store getting plugs, I'm going to get wires, cap and rotor. Oh yea, a valve cover gasket too.

I'm hoping my carboned up plugs were the main culprit... due to the other carb dumping too much fuel. But I'm probably wrong, with my luck. It makes life less boring!

If it starts, I'll blow off the old timing light get her running right.

Then I'll come pick up all you guys and a keg and make it a party bus for a night. (Parked of course.)
I'll check back tomorrow.

 

Well, I put it back together. Valve cover, then plugs, wires, cap and rotor. The new plugs I got were autolites like I took out, but a completely different length, the new ones were longer. I didn't even put the belt on or check the quality of spark. I pulled the choke and turned the key and it started and ran! I turned it off, put the belt on, restarted it and adjusted the timing to spec. Had to adjust curb idle speed and when I got it to 600rpm, I adjusted the idle enrich screw. I didn't notice much difference though, just a very tiny bit. I drove it a bit and she's running strong!

What is the standard setting for the idle fuel enrichment? Is it roughly 1 1/2 turns out from the seat? I messed with it, now I don't where I started from.

Other than that, I got the keg, but its gonna take me a few days of travel to get to you all.

Really, I do appreciate everyones help. I'm sure I'll have more questions and hopefully I can help others too.

Thanks Again!

 

So after all this it was simply a case of fouled plugs? a $10 fix, this thread should be a case study for never overlooking the simple stuff, glad to hear you got it up and running again.

 

I hope some guys on here remember this,that no one knows everything.More than once I have seen someone put down and other guys were quick to jump down someones throat!

 

Awesome!

I gotta give you props for not only hanging in there, but also giving updates along the way. All too often a fellow will post a problem and get 20 responses on what to look for or fix and you never hear from the dude again.

As for mixture screws 1 1/2 turns sounds good, but rather setting them with a vacuum gauge is much better, but I wouldn't sweat it.

I had something similar happen once. Installed new spark plugs and a week later engine wouldn't idle for crap. Couldn't figure it out and went ahead and reinstalled the old plugs... problem solved. That was 15 years ago. I suppose quality control hasn't gotten much better.

Josh

 

BTW,this truck is not a dentside!This should have been posted in the engine forum.Why do I say this?Because the last time I posted a few things on this forum about my 428 someone cried like a little girl that my post was not chassis related and had my thread moved!