Mindboggling idle issue

[ggzilla]

Just use your old condensor. If it "fixes" the problem, then I'd \think about buying a new one.

[josh_t]

ok. thats what i thought. i dont have that problem any more. i'm just making sure i am not overlooking anything before i go spend another dime on this thing.

[josh_t]

could the "new" condenser be basically out of circuit? like its not shorted but its also not having any capacitance at the same time?

[I'm BLUE]

Just use your old condensor. If it "fixes" the problem, then I'd \think about buying a new one.

 

Ditto. I try to keep a spare set for longer travels.

[josh_t]

and another strange question for you. i got an oscilloscope recently and someone asked me if i got it for analyzing stuff on cars. what exactly could i use my scope for? i'm sure its ignition related and could possibly help in this case. i've even seen a site selling an inductive clamp to put around your #1 plug wire that looks identical to a timing light clamp. it'll connect to my scope. i wonder if that would be useful for this.

[Siempreloco]

Check your wires inside you distributor, make sure none of them are shorting to ground, no wire showing through insulation, tight connections, no direct contact with baseplate, etc. Make sure your condenser is no only connected right, but mounted right on your distributor so it is not shorting out.

[josh_t]

i've checked all the wires in there, as that was one of my first thoughts. if anything is shorting inside it would have to be arcing, which wouldnt be a major stretch as there is a voltage spike when the magnetic field in the coil collapses every time it sparks. i've made the mistake of touching the primary wire going to the distributor while setting timing once and it still hurts.

[ggzilla]

It does not necessarily cause arcing. remember the points are connected to ground, not to +V inside the distributor. Stop overthinking this and try your old condensor. It won't cost you anything.

 

Also you absolutely cannot set used points accurately without a dwell meter, because used points develop pits (even when they are good) so feeler gauges are not accurate. You might have them to close, or more likely too far away. With new points you can use a feeler gauge, matchbook cover or eyesight to set the gap correctly.

[josh_t]

haha. i'll try it tomorrow. i tend to overthink things quite often. i wish you had given me a cool way to use my scope tho. ;)

[ggzilla]

Connect the scope to the coil. But you need a mechanism to step the voltage to the correct input level of your scope. Then you can diagnose all sorts of engine problems, even mechanical or airflow related by the scope of the coil. I don't know of any shadetree mechanic that has done it.

[josh_t]

i've seen someone that said they used 2 1 mega ohm and 2 kilo ohm resistors in series to bring it down to an acceptable level for the scope. i'd rather actually see some results of whats been done to an engine than by seat of the pants or by ear. and thats assuming you dont have a dyno handy lol.

[josh_t]

well whadya know? my old condenser made it work. those points look kinda rough for their short life and the "new" condenser is noticeably smaller than the old one so i think it had the wrong one in it. the two things i had in mind were coil or condenser for my suspects. i wish i had done the switch sooner. it seems to be holding up, its been a few minutes now and it hasnt acted up yet, and the timing is much more consistent. i'm getting within 1 or 2 degrees change in timing where before i was getting about double that when it was running "right".

[ggzilla]

Glad to hear it is fixed.

[josh_t]

me too. its so nice to have the hood down for a while. would you still recommend putting a brand new condenser in it? or should i just buy one and don't fix it till its broke?

[ggzilla]

Id put new points & condensor in now. Replace the points & condensor every 12 months/12,000 miles, or keep the old ones for the inevitable break down.

[josh_t]

ok. thats not a tall order, its only about 13 bucks for both.

[josh_t]

BTW guys, since i was a douche and didnt really tell you guys what happened in the long run, i've had a new job for going on 8 weeks now and its a 30 minute drive there and back 6 days a week. cold in the morning hot in the afternoon, and it has ran pretty much just dandy day in and day out. a couple hiccups but i havent had to drive my lamborfeeti's so it's fine.