» » »

Dodge Q&A

Ask Your Question

1996 Dodge Dakota Question: distributor advance bouncing

 

Question

jjddii77, 3.9L V6, Central Point, OR, November 17, 2013, 19:14
 Rookie

hooked up a real time scanner to my truck and it looks as though im getting distributor advance that bounces from 13 to 17 at idle. also changed injectors again but still get misfires codes 300 and then 301 303 305 on 1 3 5 . mostly 3 an 1 . I can drive for about 20 mins before the randoms show up they don't usually turn on the mil light. also the o2 takes a long time, over an hour before the tests get finish if they finish at all. mostly the heater on the o2. just driving down the freeway 65 mph. any ideas?

2 Answers
Flag This
  • Answer #1

    cardocIII from Gillespie's Auto Service, November 17, 2013, 20:18
    Profile_thumbnail
     Master

    The ignition timing changing is part of the PCM's strategy to keep the idle speed as close to the desired level as possible. Some IAC systems can overshoot and you end up with surging as the computer keeps changing the IAC counts. By using the ignition timing, small changes can be made on almost a cylinder by cylinder rate.

    If the system is detecting misfires, it might suspend the O2 sensor testing. You have to look at the code description and code set criteria to know for certain. Chrysler tests the O2 sensor at a very light throttle and iirc about 25 to 30mph. With a DRBIII scan tool you can command the monitor to run, and a screen is displayed that has minimum and maximum values that the driver has to stay in-between and the test will run in a few seconds, so long as there are no suspending or blocking conditions in play.

    Flag This
  • Reply

    jjddii77, November 17, 2013, 21:33
     Rookie

    thank you. I drove for almost an hour until the misfires came up as codes and I was going 65 mph on the freeway. now I am getting misfires on all but cyl 6. this triggers the ck eng light. also noticed the alternator bouncing voltage. new battery only holds a 12.7 charge. alternator is putting out 14.75 when checked. maybe the alt is going too , its the original one. I did see the volt meter in cab bouncing at night while driving. awwwwh. what next!!

    Reply
    Flag This
  • Medium-star Best Answer
    Greg's Orange Auto (14194 Answers) , Orange, CA - (714) 361-9386
    globalhelper November 18, 2013, 06:05
     Master

    poss loose timing chain?

    Flag This
  • Reply

    jjddii77, November 28, 2013, 18:28
     Rookie

    replaced timing chain and gears still have misfires.

    Flag This
  • Reply

    cardocIII, November 28, 2013, 19:07
    Profile_thumbnail
     Master

    Can you feel the misfires, or does the check engine light just flash or come on reporting some?

    Flag This
  • Reply

    jjddii77, November 29, 2013, 08:51
     Rookie

    the pending code usually comes up on the scanner with 300 first and then 301 303 305. I don't really feel them I notice that it usually happens when the road is rough leading to think loose pcm connections. the only time it sets off the check light is after there are more then 4 cyls. this is while I drive with the scanner attached to the system.

    Reply
    Flag This