Intermittent starting issues

Welcome to 2CarPros.

The most common cause of a vehicle not starting when it is hot or has been driven is a bad crankshaft position sensor. When they begin to fail, heat causes the internal winding to separate which results in spark loss to the ignition system.

Take a look through these links. The first explains what the component is, the second explains symptoms, and the last shows in general how one is replaced.

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

If that seems to mirror what you have experienced, let me know the engine size and I will provide the directions for replacement specific to your vehicle. If it doesn't seem the same, let me know and we will move to plan B. LOL

Take care,
Joe

Thank you Joe.
I will work with plan A and up date you when have a solid out come or let you know if plan B is needed.

Welcome back:

You're welcome. Let me know and we'll go from there.

Take care,
Joe

Here we go again same issue as last year hot day; many stops and get in turn the key and nothing, the dash lights came on as normal and I knew it wouldn’t start as before due to I did not hear the fuel pump pre load. after reading a lot off post at magnumfourmz, I found someone describing the same symptoms and 1- reply he got was vague but they mentioned something in the ignition didn’t make a good connect not sure if good info or not. As usual 5 minutes later car started with no problem, this is getting fun! Any thoughts?
Thank you!

Hi,

Is the starter engaging? Let me know the engine size as well.

As far as what you described, it could the auto shut down relay or again the crankshaft position sensor. I'm not sure what helped the last time.

I attached a couple pics below. If the starter engages and you don't hear the pump, switch the ASD relay with a different one in the relay box and see if it makes a difference. Also, make sure there isn't any corrosion or a loose connection.

Let me know.
Joe

Okay, thank you for diagrams. Last time you recommended changing the crankshaft position sensor and I did that already, so that shouldn’t be the problem. I will check relays as you recommend, the engine is 5.7 and the starter does not engage at moment of turning key. Again thank you for your ideas. I drive the magnum approximately 2 or 3 times a month. I am in St Louis Missouri, very humid. the car is in a garage that is not climate controlled.

Hi,

Happy to help. I just hope I do. LOL Let me know what you find or if you have other questions.

Take care,
Joe