Sluggish acceleration

Hi milt e,

Reading your description of the issue, I suspect one of two things. Fuel or spark. Sputter at higher RPM is usually timing but with this engine you will need to verify your timing is set up correctly. The history of this issue would be telling because in my experience, I would bet they have recently had some work done that required timing to be reset and if it is not exactly correct then you will have these types of issues. I attached a document that shows your timing marks to make sure it is set up correctly.

Before you take it apart, if you have a scan tool, please drive it so that it acts up and monitor your injector pulse widths and see if they are increasing while the sputtering occurs. Next monitor your short term fuel trim while it is sputtering and see if you are running lean. These will point to a fuel issue. If you find anything here, then put a fuel pressure gauge on the rail and see if you are losing fuel pressure at higher RPM.

The way this one should work is the PCM will see at the higher RPM that there is no crankshaft acceleration as expected and should start adjusting to try and achieve that. The fact that the speed does not pick up tells me it is most likely a timing issue.

Lastly, if you have a lab scope, you can look at your crank signal pattern and ensure it is a good square wave pattern because if this is not good then it could cause a sputter. This is less likely because usually a crank issue causes a stalling but if the tone wheel is cracked it could cause this sputter. This tone wheel issue will show on a scope pattern.

https://www.2carpros.com/articles/how-camshaft-variable-valve-timing-works

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