TRUCK CRANKS BUT WILL NOT START...

  • Tiny
  • thbrann
  • 1990 Dodge Ramcharger
  • 130,000 miles

5.2 318 2WD

I have determined that I am not getting a spark from the coil to the distributor cap. I changed the coil, distributor cap, rotor button, Hall Effect pick-up, verified power to coil positive terminal. I did note the voltage from the number one (of three) connector to the Hall Effect sensor is reading 9V, according to Haynes manual it should read battery voltage. Tried to trace wire for shorts and from what I can see there are none. Battery is fully charged and reads 12V. I am at a complete loss. Could it be the Computer?

Tuesday, March 13th, 2012 AT 12:46 AM

9 Answers

  • Tiny
  • billymac
  • Expert
  • 2,240 posts

Most likely crank sensor

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Tuesday, March 13th, 2012 AT 12:48 AM
  • Tiny
  • thbrann
  • Member

Do you mean crankshaft position sensor? Manual states it's on MPFI systems only. I have a carb'd system. Could it be the ASD relay?

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Tuesday, March 13th, 2012 AT 1:21 AM
  • Tiny
  • billymac
  • Expert
  • 2,240 posts

Sorry didn't notice the year. The asd relay is a possibility. Switch with another one in the relay center to try. This sounds like an ignition module. Possibly a computer.I believe the ignition module is integrated inside the computer.

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Tuesday, March 13th, 2012 AT 1:49 AM
  • Tiny
  • thbrann
  • Member

I cannot find all components to the ignition, so that would lead me to believe you are correct about the module being integrated in the computer. So, would it be best to replace the whole computer? In other words, even though the ignition module is integrated in the computer, is it still a separate module, could I possibly get away with installing a whole new ignition?

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Tuesday, March 13th, 2012 AT 3:11 AM
  • Tiny
  • billymac
  • Expert
  • 2,240 posts

No you have to have computer salvage yard can give you a good deal usually have a replacement warranty for 30 days.

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Tuesday, March 13th, 2012 AT 4:58 PM
  • Tiny
  • thbrann
  • Member

Ok, new development. I installed a mechanical ignition system, to include points distributor. In my mind this would take the computer completely out of the loop. I get fuel to the carb, so fuel pump is working. I now have fire at the coil, but no spark from distributor cap? Nothing in the distributor seems to be grounded out for the spark to just disappear. Still a computer issue? If so, what else does the computer control regarding the ignition system?

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Wednesday, March 14th, 2012 AT 5:52 PM
  • Tiny
  • billymac
  • Expert
  • 2,240 posts

No if you have points and fire. Nothing comeing out of distributor cap AND MOST IMPORTANT DISTRIBUTTOR IS TURNING. All that is in between cap and distributor is rotor

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Thursday, March 15th, 2012 AT 1:04 AM
  • Tiny
  • thbrann
  • Member

Distributor is turning. Brand new rotor, although, I will try another one. I'm thinking ground issue, but can't seem to find anything grounding out that shouldn't be. With the key "on" but not running when I manually open the point I get a spark at the point which tells me the point works. Could it be a bad condensor? Also, I feel like this is a silly question, but the orientation of a points dist. Vs. The Hall effect dist. Should be the same right? In other words, speaking in extremes, this distributor wouldn't need to be oriented up to 180 degrees the other way or anything would it? Starting from TDC the rotor should always point roughly to plug #1?

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Thursday, March 15th, 2012 AT 12:27 PM
  • Tiny
  • billymac
  • Expert
  • 2,240 posts

HI YES TIMEING IS SAME pointing to no 1 you eed to have wire from dist on neg side of coil.

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Thursday, March 15th, 2012 AT 10:25 PM

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