1996 Dodge Ram engine wont start

Tiny
CSTOKES28
  • MEMBER
  • 1996 DODGE RAM
  • 5.2L
  • V8
  • 2WD
  • AUTOMATIC
  • 168,000 MILES
I just rebuilt the motor and put it back in and was ready to start it and it wont fire. I did have to replace camshaft and crankshaft position sensor connector I rewire them three times and I all of a sudden get power to ignition coil and when I try to start it up I end up losing all power to my ignition coil its like I keep having to rewire the connectors again and again to get power to my ignition coil and then lose it once I tried to start the engine I'm puzzled by it all if I could get wire diagram to both connector I could be able to make sure all of it is set right
Do you
have the same problem?
Yes
No
Thursday, July 16th, 2015 AT 11:43 PM

4 Replies

Tiny
CARADIODOC
  • EXPERT
Sounds like you just need to understand how the system works. The Engine Computer turns on the automatic shutdown (ASD) relay for one second after you turn on the ignition switch. That sends voltage to the ignition coil, injectors, alternator field, oxygen sensor heaters, and fuel pump or pump relay. That is probably what you're seeing when you have voltage to the ignition coil. The ASD relay turns off after that one second, then the computer turns it on again during engine rotation, (cranking or running). It knows that by the signals from the camshaft position sensor and the crankshaft position sensor.

The first thing to do is read and record any diagnostic fault codes unless they were erased by disconnecting the battery. Chrysler makes doing that yourself real easy. Cycle the ignition switch from "off" to "run" three times within five seconds without cranking the engine, leave it in "run", then watch the numbers show up in the odometer display.

The next thing is to determine if the ASD relay is turning on during cranking. It sounds like you were already doing that. Monitor the voltage to the ignition coil or any injector. You should see 12 volts for one second when you turn on the ignition switch, then again during cranking. If it doesn't come back during cranking, the signal is missing from the camshaft position sensor or the crankshaft position sensor. The most common problem is the crank sensor got smashed during engine removal or reinstallation, or a new spacer wasn't used to set the critical air gap.
Was this
answer
helpful?
Yes
No
Friday, July 17th, 2015 AT 1:45 AM
Tiny
CARADIODOC
  • EXPERT
New crank sensors come with a thick paper spacer stuck on the end to set the air gap. When you reinstall a used sensor, you're supposed to get a new spacer from the dealer. A lot of aftermarket sensors have a thin plastic rib molded to the end instead. When those are reinstalled, you're supposed to cut the remaining part of the rib off, then use a new paper spacer. If no spacer is used, the sensor can be pushed in too far and will usually be broken by the ring on the flex plate.
Was this
answer
helpful?
Yes
No
Friday, July 17th, 2015 AT 1:53 AM
Tiny
CSTOKES28
  • MEMBER
Ok I tested it and only way my asd engages is by take the fuel pump relay fuse out but when I put it back in it disengages the asd why is that
Was this
answer
helpful?
Yes
No
Friday, July 17th, 2015 AT 3:11 PM
Tiny
CARADIODOC
  • EXPERT
Reread my reply. The ASD relay only turns on for one second when you turn on the ignition switch. It will not turn on again until you crank the engine, IF signals are coming from both sensors. Removing a fuse is not a test we normally do, so I don't know how anything will react to doing that.
Was this
answer
helpful?
Yes
No
Saturday, July 18th, 2015 AT 3:27 PM

Please login or register to post a reply.

Recommended Guides