After running it for a little while it starts spitting and sputtering and loses power

Hi,

What you are describing sounds like it could be related to the crankshaft position sensor. When these sensors begin to fail, they are affected by heat. When they get hot enough, the engine loses spark and shuts off or runs poorly. Then, if you give it a chance to cool a bit, it runs again.

Do me a favor. Take a look through this link. It describes the most common symptoms related to the crankshaft position sensor.

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

If you feel that mirrors what you experience, you can check if spark is lost when the engine won't start. You can do that using a live data scan tool, watching if the RPM gauge moves a bit when cranking (it won't if the sensor is bad), or you can check for spark at the plugs.

Here is a link showing how to test for spark:

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

If you find no RPM signal or no spark, the first suspect is the sensor. Here is a link that explains in general how it is done:

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

If you look at the attached pics below, they provide the directions specific to your vehicle for replacement.

Let me know if this helps or if you have other questions.

Take care,

Joe

See pics below.

This does sound like a fuel issue but if it is vapor locking then the engine would normally stall. What I would do is start with checking the fuel pressure while the engine is running so that you can monitor it while it starts to run poorly.

Here are a couple guides that will help with this issue and checking the fuel pressure:

https://youtu.be/U1RoG3I-Oww

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

You are correct that this is a returnless system but only way you would be getting a possible vapor lock is if the fuel is overheating and atomizing before it gets to the cylinder.

Take a look at the info attached for this system and let's check the pressure when this is happening and that will tell us what steps to take next. If this checks out, I am thinking we have an ignition issue and possible crank sensor issue. Here is a guide that will cover that but we can get there is this checks out:

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

Thanks