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Posted by: Ansbacher Apr 5 2018, 06:20 PM

For the last month or so my '74 2.0L (carbureted) has been getting progressively harder to start, especially when sitting after running. Today it finally will not start hot or cold. I ruled out the carbs and fuel supply. I also replaced the battery when this problem arose. I am measuring 12.54 volts on the battery (static) but am only getting 11.54 volts at the +terminal of the coil with ignition on. Should that be enough to start the car? In addition, as this problem got worse, the engine running just got worse and worse, misfiring, and erratic idle. Any ideas?

Ansbacher

Posted by: cuddy_k Apr 5 2018, 06:40 PM

First I’d check the grounds (behind battery, under relay panel, transsmission ground strap). The slow deterioration sounds like a loose ground that’s getting looser or more corroded over time...

Posted by: Dave_Darling Apr 6 2018, 12:09 AM

The coil needs less than 10V to work. It may even work with much lower voltage than that! You may wind up with lousy high-RPM running if the voltage drops low enough, but I think that would be quite low indeed!

My injected car ran with a non-functioning alternator until the center console voltmeter dropped below 9V. Not sure how much that was at the coil, but I figure that 9V was about when the injection gave up. I think it might have run quite a bit longer with carbs!

--DD

Posted by: falcor75 Apr 6 2018, 12:17 AM

There's no real load on the battery with just the ignition on, monitor the voltage when cranking and see if it goes much lower than the static reading.

Posted by: Spoke Apr 6 2018, 09:29 AM

Also you may read a low voltage if the coil is being energized when doing a static (engine not cranking or running) test. Coil current may be very high (much higher than when running) for a static test resulting in a larger voltage drop than seen when the engine is running or cranking.

Posted by: Ansbacher Apr 6 2018, 02:07 PM

OK, I got 9.5 Volts at the coil + terminal when cranking. I tried a different coil and a different condenser- still no start, just cranks. Points had just been cleaned and adjusted to a good dwell (checked when the engine was still limping). Definitely getting fuel. I cleaned the ground strap connection underneath the rear trunk, but I cannot get a wrench to the bolt that holds the other end of the ground strap to the rear of the transmission. Am I going to have to remove the muffler to get to it or is there a trick somebody knows? It does look a bit corroded and I want to clean it up. HEEELLLPP!

Ansbacher

Posted by: falcor75 Apr 6 2018, 02:21 PM

Could be a dead cell in the battery, if you have a pair of jumper leads try connecting them to another battery and try cranking again.

Posted by: Ansbacher Apr 6 2018, 04:24 PM

OK, tried to jump start the car. Would not start, just cranked. Also cleaned the ground connection above the fuse panel. Cranked a bit better but would not start. Pulled a plug to watch the spark- it is definitely weak, a reddish purple, NOT bluish white like it should be.

Ansbacher

Posted by: jcd914 Apr 6 2018, 04:29 PM

Check your points and the ground wire on the advance plate in the distributor.

Jim

Posted by: Dave_Darling Apr 6 2018, 05:48 PM

Do you know that you are not getting spark? Tape a spare spark plug to a ground, plug a spark plug wire into it, and have someone crank the starter while you watch the plug. Sparks will be obvious if they are happening.

--DD

Posted by: Ansbacher Apr 6 2018, 06:15 PM

Dave, Reference two responses up (the one from me). Yes, I am getting a very weak spark. I also tried some different timing positions of the distributor, advanced and retarded. Still wont fire. Guess it is not enough to ignite the fuel.


Ansbacher

Posted by: Ansbacher Apr 7 2018, 01:48 PM

Well, I got it running. Hard to believe, but it was plugs! Pulled out the NGKs (which looked perfectly fine) and replaced them with my used standby set of Bosch. Fired right up. What I noticed is that all of the little nipple adaptors that screw on to the threaded top of the plugs were loose as a goose on the NGKs. They would not tighten up. They went on nice and tight on the Bosch. I have to use them with the plug wires I have in order for them to snap on properly. Not sure how this happened, as things were fine when I first installed the NGKs. Anyone else run into this sort of thing?

Anyway, thanks everyone for their help on this problem.

Ansbacher

Posted by: rudedude Apr 7 2018, 02:02 PM

My honda v6 outboard motor has a slight intermittent miss and then all of a sudden wouldn't run. Turned out all 6 ngk quit at the same time. Way cheaper than the ecu I thought I was going to need

Posted by: Perry Kiehl Apr 7 2018, 09:03 PM

How old are the points and condenser?