Testing Wiring Harness

tripleD

New member
Apr 18, 2017
15
0
1
2003 lb7 California model with EGR removed. New motor installed, new injectors, rebuilt CP3, etc. lots of new parts

Symptoms : bogging, white smoke, excessive fueling, odd jerky shifts, low on power. The truck idles well, no smoke. I only see excessive smoke while driving. I have only taken it around the block and up to 40mph max for a second or two. I have otherwise parked the truck since it’s over fueling.

DTC: p0103 code, MAF reading high voltage. No other codes.

Ruled out injectors, balance rates are all in spec. It’s unlikely the new stock injectors are bad. The motor has less than two miles on it and maybe a total of 45 minutes of run time.

See below for images from Autel showing MAF reading. It is holding at a constant vs fluctuating with pedal inputs. What can cause this issue: wiring, bad MAF, both?

879ECA37-6FF1-4FD9-BBAA-F0D22AFF6C04.jpeg5FEBECDD-3A3F-4633-A1C8-0EC40036B8CC.jpegCC4E1E73-F708-48C6-9D58-179C46612DA2.jpegD15864F3-5963-4625-8626-87686973F12C.jpeg3E3582BC-152F-4EF5-A368-73513E67E508.jpeg
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,677
1,944
113
Mid Michigan
According to your signature, is this "new motor" an LBZ or another LB7? If LBZ, did you install everything LBZ related underhood?
 

Ron Nielson

Active member
Oct 11, 2009
773
147
43
Berryton, KS
Check your 5V ref and ground at the MAF connector. Appears you have a circuit problem. See attached.
 

Attachments

  • P0103.pdf
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