bad alternator cause no ignition?

[fsjcowboy]

My question involves a 1987 Four Winns Horizon 180 with a 4.3L OMC. This motor will not fire... A rebuilt carb feeds plenty of fuel to the engine. Even when using starting fluid, I can get no firing. My big question is:Can a faulty Motorola alternator cause a no-spark or a weak spark condition? The starter system operates normally. I have verified spark at the coil wire and plug wires with a test light. Dwell is a bit low right now at 31 degrees. New points, plugs, rotor, and condenser. I have removed and grounded the plugs to the engine to visually see the spark at the plug ends. I HAVE NOT replaced any plug wires or dist. cap.

 

[Bondo]

Re: bad alternator cause no ignition?

Ayuh,... I suppose Anything is Possible,...
But,.. If you've got Spark, At the Plugs, It'll run Without an alternator at All...

What did the Plugs look like,..??
Is it Timed,..??
Compression,..??

 

[gadget73]

Re: bad alternator cause no ignition?

If the voltage is low, that might do it but the alternator does not charge while you're cranking the motor. If you have spark, and you have fuel, it ought to run. The only other question is does it have compression, and is the timing in the neighborhood of where it ought to be?

 

[Maclin]

Re: bad alternator cause no ignition?

This sounds like the distributor is 180 degrees off, but don't go out there and try anything based on my opinion yet. Has it ever started and run for you? What all has been done since the last time it would start and run?

 

[fsjcowboy]

Re: bad alternator cause no ignition?

Ah-ha!!! So it will run with no alternator. Now..Regarding the timing.....the 4.3 GM motors have a reliable timing chain, don't they? The timing was set at 4 BTDC when it was running....I never thought to think about jumped timing...hmmmm? I think I'll go look at the timing and while I have the plugs out, I'll check the compression too. Thanks.

 

[bruceb58]

Re: bad alternator cause no ignition?

Don't use starting fluid. Just pour a little gasoline down the carb throat.

You sure you didn't cross any plug wires? Double check the firing order.

 

[Maclin]

Re: bad alternator cause no ignition?

Ah-ha!!! So it will run with no alternator. Now..Regarding the timing.....the 4.3 GM motors have a reliable timing chain, don't they? The timing was set at 4 BTDC when it was running....I never thought to think about jumped timing...hmmmm? I think I'll go look at the timing and while I have the plugs out, I'll check the compression too. Thanks.

What I am trying to get at is, since the 4 btdc timing was checked and set and it was running like that what all has been done? like were spark plug wires removed from the cap and put back on for any reason, was the distributor removed and put back in, things like that. The timing chain is probably ok. But a compression check should show a problem if it has slipped.