help me find an electrical gremlin, please

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Steveh if I were you I'd run with what badsport is telling you. All the gm parts in the world aren't going to help you if the pickup coil is bad. They are $20.00 bucks at autozone. Noting that I'd buy it somewhere else because thats probably where you got the switch that doesn't work right. The GM stuff will give you a better spark in the long run, but it won't cure your problem if the pickup is bad.
You could test all the wires by sticking straight pins through the insulation at either end and use the ohms setting on your meter ( should read infinity). Tape over the holes afterwards to avoid more problems.
 
Bruce,

I could pull the distributor of the barracuda and try it but i got a 1000 alignment appointment. I'm thinkin I will just go see my friends at napa and buy another pick-up coil.
 
dovercrossing,

sorry dude, didn't hit the refresh button before I posted. I agree, gonna try a new pick-up coil...I'm determined to sort this thing out once and for all
 
steveh said:
Bruce,

I could pull the distributor of the barracuda and try it but i got a 1000 alignment appointment. I'm thinkin I will just go see my friends at napa and buy another pick-up coil.
Click to expand...


Well it's an inexpensive part, and a little time to put it in. You will need to set the gap on the reluctor to .008 DO NOT use a regular metal gauge, use a brass one.

I hate to see you throw parts at it if that isn't it, but the symptoms you describe are very familiar, I have had it happen to three different vehicles.

Also, before you change part out do the two tests and then do them again after you change it. I'd be curious to see if in fact you get different results.
 
Bruce, from your earlier post: check the air gap, it should be at .008, BE SURE TO CHECK WITH A BRASS FEELER GAUGE.

Next check the OHM's by putting your leads in the wire coming from the distributor, it should be in the neighborhood of 300 to 600 OHMs. Next check the voltage output, set your meter to the lowest AC voltage setting put the leads in the same spot and spin the distributor, it should show at least 1 volt AC.



1) If the gap is more or less than .008, how do I adjust it, assume there is a sloted screw that allows me to move it in or out???

2) On the ohms test, are saying to put both leads on in the male and one in the female connection of the pick up unit after seperating the weather proof connector that leads to the ECU? Not sure I understand correctly.


Dude you have been a big help, thx again

Steve
 
steveh said:
Bruce, from your earlier post: check the air gap, it should be at .008, BE SURE TO CHECK WITH A BRASS FEELER GAUGE.

Next check the OHM's by putting your leads in the wire coming from the distributor, it should be in the neighborhood of 300 to 600 OHMs. Next check the voltage output, set your meter to the lowest AC voltage setting put the leads in the same spot and spin the distributor, it should show at least 1 volt AC.



1) If the gap is more or less than .008, how do I adjust it, assume there is a slotted screw that allows me to move it in or out???

Yes. It is on a moveable plate. Loosen the screw slightly and move the plate with a screwdriver. You will be checking the gap between the high spots on the reluctor and the pickup.

2) On the ohms test, are saying to put both leads on in the male and one in the female connection of the pick up unit after separating the weather proof connector that leads to the ECU? Not sure I understand correctly.

Yes. The two wire connection coming out of the distributor base.


Dude you have been a big help, thx again

Steve
Click to expand...
..
 
Just for giggles I went out and tested three of the dist.'s I have on the shelf.


1. Ohms 317 AC volts 1.3

2. Ohms 490 AC volts 1.2

3. Ohms 503 AC volts 1.2

Just an example of acceptable ranges.
 
tested pick us suggested,

.295 omhs w/mm set to 2k so thats almost within the 300-600 range

got .01V w/mm set on 2V setting

appears as if the pick up is shot

as for the gap testing I assume the is between the reluctor and the contact on the wiring and not the magnet right??? No way im ever gonna get .008 between magnet and the ridge on the reluctor
 
steveh said:
as for the gap testing I assume the is between the reluctor and the contact on the wiring and not the magnet right??? No way im ever gonna get .008 between magnet and the ridge on the reluctor
Click to expand...

Yup, between the magnet and the high point on the reluctor. That's why it is important to use a brass feeler gauge.

I just got to thinking about what you said. The piece in the center of the black fiber block is a magnetized. That is where you want your .008 not on the flat part next to it. Sorry if I confused you.

Something else you will want to check once you get it set is shaft movement. Make sure the shaft is free of any lateral movement.
 
Pop never said I was the sharpest tool in the shed, but after fiddling with my current set up...I dont think I can ever get it to .008. Adjusted it out as far as it will go and its a long way from .008
 
steveh said:
tested pick us suggested,

.295 omhs w/mm set to 2k so thats almost within the 300-600 range

got .01V w/mm set on 2V setting

appears as if the pick up is shot

as for the gap testing I assume the is between the reluctor and the contact on the wiring and not the magnet right??? No way im ever gonna get .008 between magnet and the ridge on the reluctor
Click to expand...

You do have it on AC volts?
 
steveh said:
I dont think I can ever get it to .008. Adjusted it out as far as it will go and its a long way from .008
Click to expand...
This confuses me. 8 mils is a very small gap, like a few sheets of paper. Does "as far out as it will go" mean you can't get the gap big enough? If true, the magnet pickup would be hitting the reluctor teeth.

You want to get the pickup as close to the teeth as practical. The 8 mil gap specified is to allow for shaft wobble and temperature growth so the teeth don't hit. You would get the strongest signal with no gap.
 
Yeh.....8 THOUSANDS, not 80, and not millimeters I haven't "miked" any credit cards lately, (example) but they are way more than .008"

(Goes to basement, comes back with caliper, mike)

Several credit cards run about .030"

Several business cards run from .010 to .015

I have a ream of Staples "multipurpose" so called "20 lb" paper.

10 pages runs .040", so TWO thicknesses is almost exactly .008"

ALSO important when you check the gap is to inspect for debri and strike damage, shaft wear and bushing play, and AFTER you set it, check that the reluctor won't strike the pickup.
 
When I talked to Steve yesterday he thought the gap was between the reluctor and the flat metal, that is where the confusion came in. He was on his way to get a pickup and a brass feeler gauge.


:happy1:
 
So I put a new pick up coil in and got noda...no spark no nothin. I've never replaced a pick-up coil before but every time I tried to set it at 008, the magnetic field was so strong that it pulled the contact into a lobe on the reluctor regardless of how hard I tightened the adjustment screw.

Took it apart again and tweaked the three prong retaining clip (bent the legs down so it would get more bite on the alignment pin. Now there is no slop and I was able to set it at 008 with no problem...stuck it back in...had a beer and went to bed ok more than one beer and went to bed.

Educate me pls...
1) obviously you don't want the reluctor bumping the contact, but will this result in no spark from the coil wire?

2) if the gap is incorrect but not touching, what are the symptoms?

3) I think I got it right now, but (tryin not to jinx myself, but I am a realist) if I still get no spark, where should I turn?

pulled the OEM coil of the barracuda so I know its good. wondering if I should swap ECUs but its a 5pin and the dart is a 4 pin
I've tinkered with it for two days now and introduced more variables so if it don't fire this morning when i try, I probably need to get back to a baseline and start troubleshooting again by the numbers from the start.

Special thanks to Bruce for all the help...

Will post again in a few
 
Did you run the test on the distributor before you put it in??

Might be a silly question but did you plug the wire together?
 
yeah, ran the ohm and volt tests on the pickup leads...300 ohm and no volts...but I was pretty tired and it was getting dark. Didn't test it after finalling getting the gap right at 008 and the pick up firmly attached so it wouldn't jump over and grab one of the lobes on the reluctor.

Bushings seemed to be good...little to no play in the shaft

Slapping it all back together now and will try again in a sec
 
oh yeah...found 67dart273's guide on troubleshooting an ECU. Will do that next if I get not spark...is that the next logical step?
 
Badsport said:
Did you run the test on the distributor before you put it in??

Might be a silly question but did you plug the wire together?
Click to expand...

Ditto. Spin the distributor by hand first and see if you get a spark. That is much simpler than cranking the engine. Best to have a spark tester, otherwise pull the coil wire off the distributor cap and arrange it to sit ~1/8" from a metal ground.

On Badsport's 2nd point, insure you have a tight, solid connection to the distributor pickup. I got a new one that had the wrong double bullet connector with a shorter male terminal that made erratic contact. A regular hardware store connector is a bit different than the Mopar connector and the manufacturer (Chinese?) must have thought it was correct.
 
I don't know if this works with some of the import/ aftermarket relacement ECU's but the originals could be triggered by shorting one or the other of the dist. connections to ground. This at least would check the rest of the system in a rudimentary way

The simple answer to the pickup gap is, if you get it too tight, it will strike and damage the coil/ reluctor, and if you get it too wide, it won't generate enough voltage to trigger the ignition. I suspect this gap depends on how good the pickup coil is, and how strong the magnet is.

I found one tune-up guy who CLAIMS to have replaced several pickups which evidently had weak magnets. I don't work with enough of these to get a good enough sample.
 
67Dart273 said:
I found one tune-up guy who CLAIMS to have replaced several pickups which evidently had weak magnets. I don't work with enough of these to get a good enough sample.
Click to expand...

in all honestly, in all my days, i have yet to lose spark over a bad pick-up in any electronic distributor even being 35 years old. maybe its luck, i dont know, but 99% of the time its been a bad ECU or ground thats caused my issues.
 
73AbodEE said:
in all honestly, in all my days, i have yet to lose spark over a bad pick-up in any electronic distributor even being old 35 years old. maybe its luck, i dont know, but 99% of the time its been a bad ECU or ground thats caused my issues.
Click to expand...


Luck, I have had three of them go out on me in 30 years. :-( The symptoms he described were identical to mine, might drive 25 miles and die, might drive a hundred and die or it might die three time in ten miles. No rhyme or reason to it.

The last one was on my 02 ram van.
 
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