1968 Impala won't start

Chuck

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Location
Billings, MT
Make
Chevrolet
Model
Impala
Year
1968
Miles
78,000
Engine
5.3L 327 cid
I started my 1968 Impala yesterday and it ran for about a minute before it died like the ignition had been shut off. When I tried it again it wouldn't restart. I tested the coil and the ohms between positive and negative was stayed between 4.3 and 3.8. When I tested the center point and the positive it stayed at 12.4 kohm. I then used a test light and cranked the motor. The test light stayed on but it blinked as the motor cranked. It's been a very lo g time since I messed with a points ignition system and it wasn't extensive, so my knowledge is very limited. Any help would be appreciated. Thanks.
 

dabunk

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Is this an HEI distributor you are working with or a separate coil and distributor setup? I am assuming you checked if it had fuel at the carb first, fuel pump working?
 

Chuck

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No, it's the original points distributor with the original drop coil. Yes, I made sure it has fuel coming into the carburetor
 

billr

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Do you have any spark at the plugs? Have you checked compression? Tried starting-fluid? Checked spark timing with a light? A timing light is also a good way to check for spark... kill two birds with one stone!
 

Chuck

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No spark at any plugs, compression is all between 140 to 144, I put in 6 gal. A month ago and it was running then. The fuel tank was empty beforehand.
 

billr

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OK, have you checked for 12V at the coil + terminal? Checked the point gap (should be about .019")? If those are both OK, I would throw a new capacitor/condenser at it. Still no joy? Then it will be time to check whether current through the coil primary is being turned on-off by the points.

I gotta ask... with the dizzy cap off, you do see the rotor turning, correct?

Compression in the 140 psig range is kind of low for that engine; are you taking compression with all plugs out and the throttle held wide open?
 

Chuck

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Like I said, my knowledge of points ignition is very limited. I never learned how to check or adjust point gaps. No, I checked each cylinder individually. Removed and replaced each plug at a time and didn't hold the throttle open.
 

billr

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OK, that compression is probably reasonable when taken like that.

Adjusting points on that GM dizzy is extremely easy. There is a screw with hex-socket drive that is simply turned one way or another. With the rubbing block of the points on the high point of a lobe of the dizzy cam, you should see a slight gap between the fixed and movable points. A Coke can is about .005" thick; cut out a piece and fold over to make four thicknesses and hammer the folds flat. That will give you a "good enough" feeler gauge for now.

The best way, and easiest with that GM dizzy, to set points is with a dwell-meter and the engine running. However you may have trouble finding a dwell-meter these days.

The capacitor/condenser is cheap, and they do go bad with just time.

How about the 12V at the coil + term? That may be 12V, or more like 6V, depending on if you are cranking or where the dizzy has stopped if not cranking, but should definitely not be "near zero".
 

nickb2

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for informational purposes HEI started in 1974

@ billr hilarious we posted again at same time

proof it aint dead yet

Yeah points, test light blinking should be be a good thing

as billr wrote. First things first.

I'm just jealous your working on a 68 327

very rare gem.

Starter fluid is maybe a bit over kill, but these 327 back then came out stock with forged rods so might take the hit.

Also, check spark KV.

On point based system should be able to crank 25 KV.

Again, @ Chuck, I know you know this, just putting that out there for other ppl who have the chance yto get thier grubby hands on that sweet ride.

winks

:bat:



If gas is old, not enough juice to ignite.

I know you know this, I am just putting this info out to revive here a bit. Not every day you see a thread on a 68 impala with a OEM 327

So here is a link for those who want to learn.

 

Chuck

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Like I said, not well versed in the points ignition, will listen to anyone who knows. Will definitely need help with lingo. The gas in it is only a month old. Before this it ran like a champ. I wanna keep it as original as possible.
 

nickb2

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also old trick fold a match book cover in two, is pretty much normal point gap if you dont have a feeler gauge.

Also, you can charge the condensor slash CAP and ground it with your body, if it snaps and hurts, it fine. But it may disrupt your pacemaker.
 

Chuck

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Location
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also old trick fold a match book cover in two, is pretty much normal point gap if you dont have a feeler gauge.

Also, you can charge the condensor slash CAP and ground it with your body, if it snaps and hurts, it fine. But it may disrupt your pacemaker.
Good thing I don't have one.....yet
 
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