Mechanics

3.9L MANUAL TRANSMISSION 4X4 INTERMITTENTLY RUNNING ROUGH STARTED DYING WHEN IDLING NOW WON'T START

1992 Dodge Dakota • 181,000 miles

1992 Dodge Dakota 3.9L Manual Transmission 4X4 Intermittently Running Rough For A Short Time, Started Dying When Idling, Now Won't Start After Dying A Week Ago.

I recently bought the truck and it seemed to run and drive without any issues. I soon noticed that if it had been running in the last couple hours it would usually run rough when started. I would drive it for about a minute before it would smoothen out. I then noticed if it was idling for a few minutes it would stall. It would previously always start right back up. I checked the diagnostics codes and got a 12 and 62. The dealership salesman said the vehicle runs excellent and has no issues. He also stated the older gentleman who previously owned the truck kept up on maintenance and recently put new spark plugs and wires in. I then gathered that the salesman mislead me and there was probably an issue that the previous owner didn't want to deal with. I put in a new distributor cap and rotor being that they looked a bit old and hoping for an easy fix.

After 8 days of owning the vehicle it again died while idling and has yet to run again. I had the vehicle towed home and have spent the last week hoping to again have the truck running. I have been researching online looking for suggestions of what may be wrong. I have been testing parts trying to find something bad before putting money into something that doesn't fix it.

Here is the current symptoms/issues:
Engine cranks but does not fire/start.
Check engine light no longer illuminates when vehicle is in the run position.
Doing the on-off-on-off-on routine no longer gives any codes.
Maintenance required light is now illuminated majority of the time.
No spark in ignition system.
I have not found any bad splices in the wiring harness but have not found all the junctions that might need to be checked.
Pin 30 of OSD relay and Fuel pump relay is about 12.5 volts.
OSD relay pin 85 and 86 is just under 12.5 volts with ignition in "Run" position.
OSD relay pin 87 is 0 volts in run and start position, -12.5 volts when checked with battery positive, 0 ohms resistance with coil Dark Green/Orange wire.
Coil Dark Green/Orange wire no voltage, -12.5 volts when checked with battery positive while in "Run" or "Start", Black/White wire on coil no voltage & no negative in "Run" or "Start"
Coil input terminals approx. 0.8 ohms, input terminals to High tension is 9,500 ohms.
Pin B & C of camshaft position sensor & crankshaft position sensor has infinite resistance (open circuit).
PCM connector and pins had corrosion, some pin outs were full of corrosion. I cleaned it the best I could until I get some contact cleaner and dielectric grease.
Cleaned battery terminals.
All fuses under hood and under dash check good except under dash #13 4 amp for accessories lights has no power on either terminal.

I am stuck as to the cause of my truck not running. I am guessing Cam Sensor, Crank Sensor, Grounded/Loose wire somewhere, and/or PCM.

Any suggestions/guidance would be greatly appreciated.
Avatar
Nickextra
April 15, 2013.



Check your fuel pressure first, or spray some choke cleaner into engeine and see if it starts. You only need the key on to get fuel should be 39 psicheck your auto shutdown relay by switch ing a like relay fuse 13 comes form headlights and grounds on other side of fuse so check for a blown fuse there it is the tan wire leading from headlight switch


Hmac300
Apr 16, 2013.
I do not have anything to check the fuel pressure. I forgot to mention I put gasoline in the throttle body yesterday to be sure I have been dealing with an ignition issue and not a fuel problem. The truck did not start with fuel in the throttle body.

I have previously tried switching the ASD relay with the others. It as well was a no go.

Fuse 13 is the only fuse that is abnormal. It does not have power on either terminal and there is zero blown fuses under the dash or under the hood. I don't understand what you mean by it grounds on the other side of fuse. Is there sometimes a rogue wire that grounds it out? Fuses have power coming in and power going out when not blown. There should be no negative in that part of the circuit.

Is fuse 13 a possibility for the reason my truck won't start?


Tiny
Nickextra
Apr 16, 2013.
Fuse13 is for taillights, it's the tan wire from headlight switch to the fuse so no this won't effect running but you might check the tan wire to seeif it is giving power to fuse. Check fuse 16 under dash and the fuse in power dist box underhood that I've pointed out. Check gray wire on coil to see if poweris coming to it. It could be a bad crank or cam sensor or if coil is putting spark out the rotor in dist cap or dist cap can be shot. Also check the three fuses fusible links I have pointed out in 1st and 2nd pics. Also if this has a ballast resistor( I don't remember) replace it as they fail and truck will try to start on start cycle but will quit when you let off key.


Hmac300
Apr 16, 2013.