1994 Buick Lesabre Electrical / weak spark problem

OLDTIMER10

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1994 BUICK LESABRE

Electrical problem
1994 Buick Lesabre 6 cyl Front Wheel Drive Automatic 175k miles

Spark plugs (new) show weak, arching, yellowish spark. Not a sharp, blue snap as normal.

Tested wires, ICM, coils, crank sensor etc.

Unplugged PCM connector & checked with test light from BAT+ to the PCM connector Pins # B11, B12, B13, &B14. The test light lit bright on each.

Checked with voltmeter from Pins #WC7, WC8, &WC9 to ground and have 11.5V

From whence does this failure come?

6 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Tested wires, ICM, coils, crank sensor etc.

What was the coil primary and secondary windings resistances-what is the voltage on the coil's positive terminal when key at run position

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Sunday, November 9th, 2008 AT 11:58 PM

OLDTIMER10

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4 POSTS

Primary side is zero Ohms with continuity. Secondary's are within range.

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Monday, November 10th, 2008 AT 12:10 AM

RASMATAZ

MECHANIC
75,992 POSTS

Do you have an HEI distributor or DIS See below info and also check the distributor pick-up coil

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Monday, November 10th, 2008 AT 12:25 AM

OLDTIMER10

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4 POSTS

I believe it is a DIS waste spark system.

Coils have been load tested independent of engine with same weak spark. Also tested new coils with same weak spark. I believe I have a grounding problem. Can you tell me the locations of ground straps from engine to body?

Thanks

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Monday, November 10th, 2008 AT 10:48 AM

RASMATAZ