I'm sure there are threads that answer my question but I'm not quite sure how to describe the problem in search terms.

In short, I have a start and stall problem. If I cold-start the D1, it starts up just fine. However, when I get to my destination and turn the engine off, I have to wait about 10 minutes before it will start again. Otherwise it'll just spin (I assume the starter motor is doing its thing but the engine never engages). Sometimes it'll engage and the engine will shudder as though the fuel mixture is wrong.
The other half of this problem just came up last week. I cold-started, drove to get a quick bite to eat, and the D1 stalled out in the drive-thru lane. Had to get a push to a parking space. Again, 10 minutes later, no problem starting up.

Fuel pump? Vapor lock? Sensor issues?

 

Sounds like it could be a problem some folks describe, being a partially faulty Crank Position Sensor (CKP Sensor), although it has not happened to me. When the CKP sensor fails completely, the truck will not start at all. I read some folks splash water down there to cool the sensor down.

The CKP sensor resides down on the left side near the exhaust down pipe, so it can get very hot there, especially if the heat shield is degraded or missing. The original heat shield is made of foil covered fiber, which can loose the foil and become all frazzled. I replaced mine with some sheet aluminum, attached using a spare bolt hole on the underside. Some folks simply use aluminum foil. At any rate, it is handy to have a known good spare CKP sensor. I keep my old one in my trail bag after it was replaced with a new NTK model.

 

I'd bet a few dollars on the crank sensor. It resides on the opposite side of the block as the starter motor. When they start to fail they become heat sensitive.

When you replace it, be sure to take a close look at how the spacer is situated. You will need to put it back the same way and it can be confusing.

 

Besides the CPS I have also seen the Fuel Temp Sensor on the fuel rail go bad. When it does it makes the ECU think the fuel is hot so upon a restart the engine just turns over, but it doesn't start. You can simply unplug that sensor to test it the next time it won't start after being warmed up on a drive. If it still doesn't start I'd go with the CPS. A lot of the D1's running around these days probably don't even have the little heat shield on the CPS which shortens their lifespan.

 

This is all fantastic information and I will check all of the items mentioned. Thank you for the guidance!

 

FYI - You can hear the fuel pump running (in a quiet area) with the key turned to on but without starting the engine. Note: it will shut off after several seconds if engine is not started.

 

Here are some pics of the heat shield thingy.






Hope the tip of your sensor doesn't look like this.

 

Replaced the CPS today with a part from AB. Installed, no start. Cranking but never engaging. I put the old one in and I got a sputtering start. Died a few times but then finally settled down and ran.

I had this thing in the sun on tire ramps, so I’m wondering now if it’s a fuel issue. Tank nearly empty and pump bad/weak plus incline = sputter?

Yet, why did the new CPS fail to do anything? Tried both spacers. Spent all afternoon. Nothing to show for it.

 

Sorry to hear that. Unfortunately, just because a component is shiny and new does not mean it is functional, could be bad out of the box. I had good luck with a new CPS from NTK (on sale now for under 40 bucks). I use the old one, which was still working well, as my "known good" spare. Maybe you could get help from another owner to swap in a "known good" CKP sensor from a working vehicle. Did you leave the fuel rail temp sensor unplugged (suggested above)?

 

I had similar issues with mine. I ended up replacing the wiring and then enshrining the wiring in some heat resistant tape. My issue was that the wiring itself was faulty because of the heat and making the wiring brittle. If your heat shield looks like the one pictured below, the wiring cannot be much better.