Engine cranks no start

LEE PAPPILLI

MEMBER
1999 DODGE RAM
5.2L
V8
2WD
AUTOMATIC
300,000 MILES

Had to repair a freeze plug that called for removal of the transmission. After doing the repair and reinstalling the truck just wouldn't start. I have checked fuel pump relay and fuse and they are fine, but I don't hear the fuel pump cycle. I keep hearing about a crank shaft sensor maybe being the culprit but not understand how it could have been affected during the process. Please help, I am going nuts. Thanks

Friday, October 8th, 2021 AT 6:37 AM

3 Replies

SQM

MECHANIC
6,383 POSTS

Hello,

As you know you will need spark and fuel to start the engine (and compression).
If the fuel pump is not coming on that could be issue.
Have you tried swapping the fuel pump relay?
You can also test that relay as well:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Just to clarify, you did not have this no start issue before you did the freeze plug, right?

The crank sensor could be the culprit but first make sure that you are getting fuel to the injectors. As I don't see any reason for the crank sensor to go out, unless it was bumped or something not aligning properly.

Have you checked to see if you are getting spark?

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Please let me know what you are experiencing.
Thank you.

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Friday, October 8th, 2021 AT 8:25 AM

LEE PAPPILLI

MEMBER
2 POSTS

Thank you for responding. So, to answer your question, no spark or fuel to fuel rail. Bypassed the fuel pump relay and was able to get fuel that way but only by bypassing otherwise nothing for fuel or spark. I did some further inspecting though and found that a three wire plug that I believe to be transmission neutral safety switch had frayed wires that were making contact with one another. Only by assumption I'm thinking this could also be the culprit. It may have caused this chaos. There was no problem whatsoever though before the freeze plug was replaced and transmission pulled back a little bit while doing this repair. All plugs were pulled before moving transmission, so these are likely suspects now, crank sensor, neutral safety switch. I'm going to repair frayed wires for neutral safety switch then reconnect it after resetting pcm and keep fingers crossed. If that doesn't solve problem, then I will be back to stage one again and in need of further assistance if possible. I'm grateful for all time taken to help me so again thank you. Lee

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Saturday, October 30th, 2021 AT 9:30 AM

SQM