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1994 Pontiac Firebird Repair Question


Topics covered: Battery, Spark, Air intake tube.
Mileage: 117,500 miles.

Asked on November 12, 2012

Pontiac Firebird Battery Problem

When running the car (3.4L V6, Auto) there is a noticeable intake backfire coming from the air intake tube. I have checked the spark (looks yellowish) and checked the input voltage at the ignition control module. It is two volts lower than battery output voltage (i.e. battery is outputting 12.5 volts, and the voltage at the module is 10.5 volts). So, I checked voltage at the fuse (under hood) and it is at 10.5 volts too. Why would there be such a large drop? Is there a wiring diagram for power distribution for the fusible links, so I can trace out the wires and check all hidden graounds?
Avatar Asked by mwillie73

Answer

Replied on November 12, 2012

Have ALT tested low voltage and yellow spark will cause missfire

Tiny Answered by Docfixit (expert)
18,420 answers provided
Replied on November 19, 2012

Alt is New (less thatn one year old), but I took it and tested it at a local auto parts store. It tested good. The voltage drop measure was taken with the engine not running.

Tiny Response from mwillie73
1 question asked