PCM LACKS POWER SCANNER SHOWS NO CODES

Tiny
SPORT454
  • MEMBER
  • 1991 GMC SUBURBAN
  • 30 MILES
HEY. V2500 5.7 & 4L80E WITH THE "7060" PCM LACKS POWER. SNAP-ON "BRICK" SCANNER SHOWS NO CODES. DATAMASTER ALDL DATALOGGER SHOWS ONLY 11 TO 24 DEGREES OF SPARK ADVANCE. REFERENCING MY '91 454SS W/THE SAME TRANS & PCM SHOWS FROM 22 TO 40 DEG]

Changed engines twice, rebuilt trans, tried high stall & low stall converters. Every component has been changed at least twice. Until I found the data logging software I had no idea what else to do?
Monday, January 30th, 2012 AT 7:33 PM

1 Reply

Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
If this is tbi then check for a blown gasket at bottom of tbi unit. Fuel pressure should be 9-11 psi as well. Cross A&B on aldlandcount flashes to see if anything other than 12 comes up.
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Monday, January 30th, 2012 AT 8:44 PM

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