2001 Dodge Ram P/U magnum v8 turns over but won't start.

CHUCK06

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I am working on a truck, a 01 Dodge ram automatic,209000 mi. with the magnum v8. The owner was told it was likely the crank sensor, if you crank it over long enough will act like it might start but does not. I replaced the crank sensor and nothing changed. He said there was a red light on the dash that came on and stayed on when the starting issue occurred. I found this light is part of a aftermarket alarm/anti theft system, I removed the alarm kit and reconnected the interrupted wires, however there are five wires that had pinch on spade terminals, like you see on trailer light wiring, all the wires there seem to have continuity, the fuel pump kicks on, I have not tested the fuel pressure, have not tested ignition (did not have the tools with me, will do all that tomorrow after work). just looking for some pointers and or common starting issues that may be specific to this vehicle. As always, any advise is greatly appreciated.
 

CHUCK06

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Also wondering, this truck has a timing chain, not belt.....right?
 

Mobile Dan

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It has a chain.

The wire that sends crank signal from ignition switch is the one that usually needs to be refastened after aftermarket alarm removal.
 

billr

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Be sure to take a can of carb-cleaner with you, to try as primer-fuel into the intake.
 

kev2

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Start simple easy things first...

Confirm that the CEL illuminates during start or in run posotion- should come on them go out in @3sec.

FUEL PRESSURE use a gauge....post reading..

Check for spark at several cylinders.

Try BillR's suggestion- spray carb or brake cleam into intake as someone tries to start - give us some info and we aill try somemore
 

CHUCK06

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What fuel PSI am I looking for? There is a shrader valve (test port) on the fuel rail? I will test the ignition and fuel psi tonight.
 

CHUCK06

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I went to the truck yesterday, and got the engine to start and run, with a high pitched knocking that I traced to the crank sensor area. The new crank sensor is identical to the original and don't know of any shimming to be necessary, next time I go to look at it, I will remove the inspection plate and check the flywheel and torque converter. The owner said the transmission was replaced a few years ago (professionally) I'm wondering if maybe something came loose.
 

CHUCK06

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There were no signs of damage to the old sensor, and the depth of the new sensor is identical, but the sound is distinctly coming from that area (most audible at the crank sensor. ) Normally if something is hitting the sensor it will run for only a few seconds before the damage is done and the sensor fails, hmm, mind boggling, I really think maybe something is up with the flywheel, I'll know when I get back over there and look at it.
 

CHUCK06

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Okay, I take it back, upon closer inspection you can see on the tip of the old sensor some signs of rubbing, it is worn down to the point that you can see the two metal prongs on the tip where as the new one is smooth and sealed, it is worn so smoothly that only under good light can you see the rub marks on it, what does this likely mean as far as repair?
 

CHUCK06

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according to the vehicles owner, there was no audible knocking or tapping prior to the no start issue.
 

billr

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The trigger-wheel for that crank sensor is part of the harmonic balancer (HB), right? Can you tell if it is on the hub of the HB, rigidly mounted to the crank, or on the outer ring of the HB, where it might be running eccentric if the HB rubber has gone bad? If you remove the crank sensor and measure depth to the trigger-wheel, with the crank rotated to several different positions, that will give you a clue as to why that old sensor got rubbed.
 

kev2

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I think this chrysler CKP is mounted on the rear block 'bellhousing' area and is triggered by the Flywheel/flexpalte notches, often confusing.

My thoughts woulb be- as mentioned is the CKP showing any contact with Flex plate? It is an OEM sensor? Any CODES? - with sensor OUT is the sound still present?
 

Mobile Dan

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Kev2...won't run with the sensor removed...and hard to hear a noise while the starter is cranking.

Maybe the bellhousing moved if dowels are missing. I know it's a bitch to get to that sensor, but you need to check it for impact. A quick and dirty fix might be to put in a spacer to raise the sensor a bit, if clearance is the problem.
 
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