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engine startig question

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JPSmit

JPSmit

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elsewhere you have been following the adventures of my new alternator.

all of a sudden it is much harder to start. it backfires some, then starts and dies. Last night, I had it running for 20 minutes and it was OK - but even there, I had to adjust the idle.

the only thing different is the alternator (and yes, it is colder out ) any thoughts anyone?
 
Loose vacuum hose.
Choke not strong enough, but that shouldn't cause a problem after 20 minutes.
I've heard of some alternators having a bad diode and causing AC current to infiltrate the otherwise DC system. This can cause electronic ignition problems. Easily measured with an AC voltmeter. If anything above zero, bad diode.
 
If this all started after putting in the Alt maybe you disturbed a connection somewhere that was ify and made it worse, coil lead, tach lead vac hose.I would poke around there first. Simple things first.
 
racingenglishcars said:
Loose vacuum hose.
Choke not strong enough, but that shouldn't cause a problem after 20 minutes.
I've heard of some alternators having a bad diode and causing AC current to infiltrate the otherwise DC system. This can cause electronic ignition problems. Easily measured with an AC voltmeter. If anything above zero, bad diode.
Click to expand...

what/ where do I measure?
 
vacuum is hooked up - will check connections later. back to the AC - help?
 
1-3-4-2 counterclockwise

(don't ask me how I know)
 
I think what they are saying about the AC is to connect across + and - while your meter is reading AC volts. Should be zero.
 
Has the timing been changed?
 
I think I would look into a spare coil, roter, and condencer at this point.

Just get em off the shelf at your local parts place JP, cheeper is better.
 
OK - had it running tonight (Oh - and I will check everything else I promise) was a rough idle in that it took a bit to settle down - would race a little and then loose a little. the longer it ran the better it got (the idle that is) when I shut it down after 5 min or so, it started instantly. some seems to be needing to take a look at the throttle return spring. - will check that also.
 
Well done JP. It's all golden now.
 
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