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  View original topic: '71 problems and spark is one.
bacod253 Wed Oct 01, 2014 12:52 pm

So let me start from the beginnings of the situation, in case things are related.
I was driving back to Portland from Eugene when my generator pulley cracked around Albany. Didn't have a spare, so I went without for the rest of the drive. Tracked down a replacement, slapped it on, but the generator light remained on, flickering sometimes at highway speeds. Replaced the regulator after charging the battery. She worked for about a week, and then the revs wouldn't get past ~1200, or so it seemed whereas I don't have a tach. She idled well, but put any sort of load, or tried to rev her up and she'd die. Changed the plugs, cap, rotor, condenser, points oil change/valve job. Cleaned the carbs/jets, and when that didn't work swapped with a another set that I had laying around. Still idled/died under load. Compression test showed 130 lbs on #3, and 145lbs on the rest. I got it into my mind that maybe it was the mechanical advance of the 009 that was goofed up, and thus died when any advance was put on the engine, so I pulled the distributor and swapped it with my spare that I carry around. Now no start. swapped back to the first one that was on it when it was running. No start. Tried the Muir coil test and no spark came out of the coil wire. (I can see the points moving along the dist. cam, so that should work even if the dwell isn't spot on, right?) Got a new coil installed, but lost my garage assistant, so can't do it again...

So. My only thoughts are, 1) Battery. Could it have enough juice to crank the starter, but not enough voltage to spark the coil? 2) Maybe the coil ignition wire is now giving out? Voltage reads at 12-14v with key on. Could try a jumper directly from the battery. 3) Ground strap? 4) Coil ignition wire. My multimeter continuity test doesn't show continuity, but with resistance loaded in them nowadays wouldn't that show a false negative? Ohm test reads at 5.6 on the old wire and 5.5 on a type 1 wire I have laying around, but isn't long enough. What should that wire read at, and how would one know it's bad if you can't use a continuity test? 5) Maybe I should try yelling at/kicking it?

Cranking it over and over gives me a slight gas smell, so I assume the fuel pump is working and it's not a fuel delivery problem. The bowls have always been full every time I've removed the carbs. Seriously at my wits end. About to buy a tow bar, and pay the local ACVW garage however much they want to do exactly what I've been doing...

KTPhil Wed Oct 01, 2014 3:02 pm

bacod253 wrote: Tried the Muir coil test and no spark came out of the coil wire.

This is the smoking gun. Check the coil and all low voltage wiring connected to it. Disconnect your choke and/or pilot jet wires, in case they are causing a short in the ignition circuit.

bacod253 Wed Oct 01, 2014 4:14 pm

Replaced the coil, and no effect. I'll have help tomorrow morning to check this coil as well, but it's new out of the box. Considering getting an in-line wire checker to see if voltage is flowing down the wires, or stopping further up.

KTPhil Wed Oct 01, 2014 4:24 pm

Did you disconnect any choke or other wires connected to your coil?
You can even remove the wire to the points and use a jumper to open and close the 12V circuit, and then see if the spark jumps, to where it fails form the coil to the plugs.

bacod253 Wed Oct 01, 2014 5:09 pm

It's got ICTs. No fuel cutoff solenoids or chokes. Only the condenser oat the 1 terminal, and the ignition wire to the 15. I've left off the reverse lights for the time being. I'll try and jump the coil next.

KTPhil Wed Oct 01, 2014 9:18 pm

Process of elimination. Remove and bypass all you can, and if it then works, add back your components until it fails again.

mastermisery Sun Oct 05, 2014 5:04 pm

I had the same issue when my last 009 ended up shorting itself internally and didn't have a solid ground on the breaker plate. No ground in the distributor will cause no spark. Also when i installed a new 009, it fried the power wire to the coil, not just blow a fuse, as everything else on that circuit still worked. I bypassed and installed a new switch with a inline fuse to the coil, now i basically can turn off the motor 2 different ways.

I also had the idle problem that ended up being intake manifold gaskets. either it idled OK at start then progressively got worse, or i couldn't give it any gas as it would take too much air. check the intake bolts as compression is not affected there.

Slow 1200 Mon Oct 06, 2014 3:24 am

being a 71 the ignition switch is always a prime suspect!



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