Mustangmike, I think he is still using stock points. He had mentioned in one post the point gap was set at 0.016". It should be a simple diagnosis, 15 minutes or so. It's more difficult to diagnose on the internet because you cannot see everything that is happening. And I don't know if he has the tools needed available to him, test light, DVOM, spark tester. Something simply is not quite right, timing off a little too much, bad plug wires, bad condenser, rotor, cap, etc. I'm sure you know how reproduction stuff is these days. Many times the quality is not very good.
(11-25-2018, 02:40 AM)1969_Mach1 Wrote: Mustangmike, I think he is still using stock points. He had mentioned in one post the point gap was set at 0.016". It should be a simple diagnosis, 15 minutes or so. It's more difficult to diagnose on the internet because you cannot see everything that is happening. And I don't know if he has the tools needed available to him, test light, DVOM, spark tester. Something simply is not quite right, timing off a little too much, bad plug wires, bad condenser, rotor, cap, etc. I'm sure you know how reproduction stuff is these days. Many times the quality is not very good.
Yes, I understand completely. Over the internet can be difficult It sounds like no or very little spark at all based on how fouled the plugs are. I know he has power to the coil. If the distributor is installed correctly with the number 1 piston at TDC and the rotor pointing to number 1 spark plug on the cap and the spark plug wires follow the correct firing order it has to be a faulty coil, condenser or possibly the distributor.
My70Mach1 have you ruled out a faulty ignition switch? I am not sure I know the complete history of the car or your experience working on cars.
Here is a picture of the ground wire in the distributor I was referring to.
So I have plugged a spark plug in number one wire and touched it to the shock tower and it has a spark but it's a red orange color spark, so tool out all the plugs so that the cylinders can dry out thinking that may be way it's not starting bc they are flooded out,
Mustangmike, I don't recall ever seeing that. That means nothing because it looks very original.
My70Mach1, How large of a gap did the spark jump? Do you have a DVOM to test the spark plug and coil wires like I mentioned earlier? If not, for a quick test at least get a different coil wire and test the spark coming out of the coil. Take it off another car if you can. Basically, if the tools for testing different items are not available, eventually, you have to start swapping out parts.
Here is some spark information I found on another website. It might be helpful. The 7/16" gap mentioned below is for stock low output ignition systems like the old stock points type. High output electronic ignitions will jump gaps of about an inch.
Quote:On an automobile ignition system the spark should be bright blue. That's because the compression ratio is higher than that on an air cooled small engine. An automobile engine operates under a transient condition where the RMP's change so fuel demand changes. Where with most air cooled small engines they operate under a static condition or a steady state.
Compression ratio of an engine and the amount of fuel being delivered can have an effect on how well the spark plug fires. This is called quenching the spark. A low compression engine running at a steady state with a constant fuel supply won't quench even a spark plug with a yellow spark. But on an automotive engine with a higher compresssion ratio and under transient conditions the yellow spark can get quenched thereby causing a misfire.
Quote:The recommended 7/16" gap has always worked for me on outboard motors. I use mine in line between the spark plug installed normally in the engine and the plug wire. This means that the spark must jump the 7/16" gap and the spark plug gap in the motor while running. You can then also increase engine rpm to verify spark at higher speeds. My experience has shown a strong blue spark with a noticeable popping noise in a healthy ignition. The gap is determined by the amount of voltage generated by the ignition, spark plug gap, and the compression ratio. Most manuals will give an air gap recommendation for a spark test. An air/gas mixture at high pressure creates a much denser gap for the spark to jump then in out in the open.
I'm not sure of the gap on the plugs I will have to check them, I want to say I just took them out of the box and installed them...I know I should have che jee them before but it ran with them in for about 25 minutes the first time I got the engine back together. I keep thinking if I have a valve adjustment issue? Is that possible to have a no start issue. Man newer cars are nothing like older cars. I do have a multi meter I used it today to check the black wire off the distributor to make sure it was not ofl and it was not ohm load was low.
Hey guys, I have to run out to a fund raiser pretty soon but I found this article on another site. I didn't have time to read it in its entirety but you look like it may by more helpful describing some of the tests that need to be performed.
(11-25-2018, 06:28 AM)My70mach1 Wrote: I'm not sure of the gap on the plugs I will have to check them, I want to say I just took them out of the box and installed them...I know I should have che jee them before but it ran with them in for about 25 minutes the first time I got the engine back together. I keep thinking if I have a valve adjustment issue? Is that possible to have a no start issue. Man newer cars are nothing like older cars. I do have a multi meter I used it today to check the black wire off the distributor to make sure it was not ofl and it was not ohm load was low.
I missed or you had not mentioned it ran for 25 minutes. How did you adjust your valves? Is it a hydraulic or solid lifter cam? They would have to be so tight there is little or no compression to not run.
270 MAGNUM 400 FORD comp cam, hydraulic lifters roller rocker arms. I righted them one at a time with an engine bump starter switch, and adjust each one just before compression stroke just enough for the push rod to not have movement rolling it in my fingers, ya it ran when I first put engine back in car and when it was on engine stand is when I adjusted valves bc I was told to do them cold so they would not change as much when it gets hot. Started it up ran just the valve where making alot of rattle, shut it down adjust then again, started engine, it ran for 15 minutes or so then shut down as if it lost power like the battery drained out, readjusted them again feeling that they where too tight, now wont start and run, but once in a while it will try to run and then is when all of the fouling out of plugs and seems to not firing correctly has happened.
I like Comp's Magnum series cams. The Magnum 270 not too aggressive and is a good cam choice for a reliable daily driver. Your power brakes will operate just fine with it. Also, the lobes on Magnum cams are a little aggressive but not as much as their Xtreme series so it is easy on valve train parts. I don't know if valve adjustment is your issue. But I would definitely readjust them following the method outlined in the Comp Cam instructions. It takes more time but it's a sure fire method to be certain the lifter is on the base of the cam lobe when adjusting the valve for it. Even if it doesn't fix your issue, you will know it's correct and can rule it out as part of the problem.
If valves are too tight you sometimes start hearing popping through the carb or exhaust and the engine will run rough.
How does the motor sound when it cranks? It should have a nice even rhythm.
During that 25 minutes of running, was the choke open or closed on that Holley 750? If closed, it would definitely flood the motor and the motor will eventually die.
***** I am guessing you have a flat tappet type cam and lifter, these NEED break in oil. Comp offers it, Joe Gibbs Racing offers it, and maybe some others. It has a high zinc phosphate content to protect the cam and lifters. Otherwise, you are at risk of ruining the cam and lifters. The cam lobes and bottom of the lifters literally grind away. Then you can imagine the other damage after metal gets into the oil. Most of todays oils have the zinc phosphate removed. After break in you still need a high zinc phosphate oil like Lucus Hot Rod and Classic Car oil and I think Valvoline Racing oil. There are likely others as well. If you have the hydraulic roller version of the Magnum 270, break in oil is not necessary.
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