1989 D100 3.9L a/t Pinging issue

[PlumCrazy4Mopar]

I just acquired a 1989 Dodge D100. This truck is the 3.9 L automatic. The codes displayed are 12, 23, 55. This truck was described as having a knock. I hear a lifter, but otherwise the truck pings badly. I was hoping for some ideas as to where to look to correct the issue. I know for the most part the computer sets the timing. It shows 38000 miles. Probably 138000 or more. I am thinking about the timing chain. Thank you.

 

[65 sporty]

Code 12 is from battery disconnect, 23 is IAT (intake air temp) voltage too high or too low, 55 is the end of code messages.
This will help
Chrysler Computer Codes, 1980s-1990s

If it's pinging(spark knock) start with the ignition timing. The computer can control timing, but you can set the base ignition timing. I believe you disconnect the coolant temp sensor to set the base timing.

 

[PlumCrazy4Mopar]

Thank you, 65 sporty.

 

[65 sporty]

Glad to help, hope it all works out.