1994 Buick Lesabre Electrical / weak spark problem

Tiny
OLDTIMER10
  • MEMBER
  • 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?
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Sunday, November 9th, 2008 AT 11:33 PM

6 Replies

Tiny
RASMATAZ
  • MEMBER
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
Tiny
OLDTIMER10
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Primary side is zero Ohms with continuity. Secondary's are within range.
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Monday, November 10th, 2008 AT 12:10 AM
Tiny
RASMATAZ
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Do you have an HEI distributor or DIS See below info and also check the distributor pick-up coil


http://www.2carpros.com/forum/automotive_pictures/12900_d1_3.jpg




http://www.2carpros.com/forum/automotive_pictures/12900_d2_3.jpg




http://www.2carpros.com/forum/automotive_pictures/12900_d3_1.jpg

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Monday, November 10th, 2008 AT 12:25 AM
Tiny
OLDTIMER10
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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
Tiny
RASMATAZ
  • MEMBER
Check ground point G120 above the AC compressor


http://www.2carpros.com/forum/automotive_pictures/12900_pcm_ground_1.jpg

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Monday, November 10th, 2008 AT 2:01 PM
Tiny
OLDTIMER10
  • MEMBER
Removed wires, cleaned and applied dielectric grease at G120.

Also, checked b11-b14 with multimeter which check ok.

Thank you
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Monday, November 10th, 2008 AT 2:10 PM

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