No start after replacing crank sensor

stev0n · Jun 6, 2017

Cliffnotes: 2002 4.7

-Driving truck home & out of nowhere it started bucking real hard like violently shaking. Acting like it was running on 1 cylinder & trying to stall.
-Tried to make it the 7 miles home
-about 2 miles later it dies.
-tries to fire but won't stay running more than 1-2 seconds
- Get CEL/Scanner says crank sensor code
-replace crank sensor & scanner shows no more code
-Truck will turn over, but not fire. No spark.
-Sprayed starting fluid in throttle body to make sure it wasn't a fuel problem & it didn't try to fire.
-Checked all fuses & relays connected to ignition/coils/etc = ALL GOOD

What should my next step be? Try a different crank sensor (that was a job getting the first one out)? Try cam sensor?

Before this happened my oil pressure gauge would randomly drop to 0 at stoplights, then go right back to normal. So i think the pressure switch was going bad. Don't know if it's related.

WilliamS · Jun 6, 2017

unplug the sensor and see if it starts. If it does then the sensor you replaced is bad. Unplugging it will set a fault which will use a base map and sensors to keep it running (well kinda running). If it still doesnt start then there is something else wrong.

bart.warner · Jun 6, 2017

Loosen the throttle sensor and trun it to left with bolts still in and tighten it back down keep holding to the left the whole time. Should start up as far as the oil sensor goes of oil is on it replace as well mine did the same thing and my Uncle is a retired mechanic and he told me to do this and it worked. Hope this helps.

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stev0n · Jun 6, 2017

Unplugging the crank sensor made no difference. Still wouldn't attempt to fire and gave me a p0320 code.

Turning the throttle sensor to the left made no difference. Either

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stev0n · Jun 6, 2017

Ok after plugging the crank sensor back in I AM getting spark. At least to the #1 cylinder. And I tested the fuel rail again & I have pressure.

But still no start. the #1 piston is at the top when the timing mark is at TDC as well

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stev0n · Jun 7, 2017

Bump

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stev0n · Jun 14, 2017

Bump. I've got fuel at the rail, spark at the plug, & it still won't try to fire.

No ideas from anyone? A mechanic told me to test that the crank sensor is getting 5v at the plug, so I will try that the first day it stops raining. he also said to look for the phrase "nobus" on the cluster, but i don't see it anywhere.

I don't have the money for a mechanic or the money for a rental car, so I HAVE to try to figure this out. any input would be a blessing.

Mikecollins · Jul 12, 2017

Mine is doing the exact same thing i thought i had it sorted out yesterday but it is back now, i cleaned all the electric pins and connectors on fuse box and pcm and it was running decent yesterday but now it is hard start again

fastf · Jul 20, 2017

If you are getting fire to the plugs and fuel to the fuel rail.This is a wild guess a mass flow sensor will cause a engine not to start too.You know anyone that has a scanner that can get down into the trucks computer I'm not talking a code reader one a mechanic uses not Autozone.Drive Safe and Be Safe and May God Bless.

rmjmaddog · Jul 29, 2017

Allow me to through my problem in on top of this. After towing a heavy load for several days by tack quit working. I pulled into a gas station to fill up my thirsty V10 shut if off fill it up and it hasn't started since. I pulled codes (P0320 / MIL 11) same code just two different ways to get them, scan tool or key on off three times. I found the tack issue, wire melted to an AC request Relay wire in the wiring harness just down stream from the PCM. I fixed tack wire issue and check the wiring to both the Cam and Crank sensors, no issues there. I replaced both cam and crank sensors with new ones. No change still throws a P0320 and MIL 11 code. I ohm checked the coil packs primary and secondary winding's, all good. The ASD relay works when the wire that is supposed to be grounded by the PCM is jumped to ground. I replaced the PCM and still same problem and same codes.
Any ideas?

Mikecollins · Jul 29, 2017

rmjmaddog said:
Allow me to through my problem in on top of this. After towing a heavy load for several days by tack quit working. I pulled into a gas station to fill up my thirsty V10 shut if off fill it up and it hasn't started since. I pulled codes (P0320 / MIL 11) same code just two different ways to get them, scan tool or key on off three times. I found the tack issue, wire melted to an AC request Relay wire in the wiring harness just down stream from the PCM. I fixed tack wire issue and check the wiring to both the Cam and Crank sensors, no issues there. I replaced both cam and crank sensors with new ones. No change still throws a P0320 and MIL 11 code. I ohm checked the coil packs primary and secondary winding's, all good. The ASD relay works when the wire that is supposed to be grounded by the PCM is jumped to ground. I replaced the PCM and still same problem and same codes.
Any ideas?

Which pin on the relay is the griund to pcm i would like to jump it out to test and see if it will idle.

So far i have replaced pcm with used one, pcm with used one, cam and crank sensor, iac, throttle position sensor, instrument cluster (took it apart and had burnt circuits for sure), new battery. Gnna change out the ignition swith tomorrow, still no idle i have recently found oil in tailpipe im thinking intake gasket not head. Any other ideas

SYKRAMMAN · Aug 1, 2017

If you need a jumper on the auto shut down relay in the tipcm (fuse box ) then you need a new tipcm. Same thing happened to me. They corrode quickly on these 02 4.7's and you really can't tell unless you open it and see all the corroded traces on the board. But a bad tipcm will cause all kinds of ghost in your truck trust me.

Mikecollins · Aug 1, 2017

SYKRAMMAN said:
If you need a jumper on the auto shut down relay in the tipcm (fuse box ) then you need a new tipcm. Same thing happened to me. They corrode quickly on these 02 4.7's and you really can't tell unless you open it and see all the corroded traces on the board. But a bad tipcm will cause all kinds of ghost in your truck trust me.

I realize this which is why i would rather test it with jumper 1st to confirm before just spending 600 buck

No start after replacing crank sensor

stev0n

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WilliamS

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bart.warner

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stev0n

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stev0n

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stev0n

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stev0n

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Mikecollins

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fastf

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rmjmaddog

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Mikecollins

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SYKRAMMAN

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Mikecollins

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