P0216

I started seeing a p0216 code and random surging/missing on the highway. Swapped PMD but code comes right back. Checked time set and actual timing is around 17-18°. With desired at 12° with time set off and 0° with time set on. Solenoid closure time varies between 2.17-2.21ms, which I know is high.

My question is, assuming the stepper motor is bad (it doesn’t move with time set on / off), would that cause high closure times and higher then desired timing, or am I most likely looking at a bad pump?

How many miles are on that pump ????
My experience with the DS4 pump has been that random timing codes can often be attributed to a failing pump

Before we jump off the deep end lets try a simple task
Disconnect the batteries and make sure all the connections are clean (Both ends)

With the engine running...Make sure both batteries are at 14.5 volts.....

Be sure the Ground wire at the injection pump is connected....Many times these wires get moved when remote PMD mounting has been done... THIS WIRE NEEDS TO STAY ON THE IP....

If all seems well.....Reconnect the batteries and clear any codes..

Run the engine and see wassssup....

If the codes returns.....We need to dig further.....

The fuel solenoid (inside the pump) must respond very fast and over time they wear and or get sticky ....

An erratic solenoid can cause the bump/miss you feel.....

You can try adding a couple quarts of ATF to the fuel tank......The cleaning and lubrication may help loosen a sticky solenoid......

THIS IS NOT A FIX...But may help diagnose/narrow the issue.....

If the issue gets better....Code stays away for a while .....The only fix will be to get the IP rebuilt by a qualified Stanadyne authorized injection shop.....Stay away from online sellers.....Too much junk out there.
There are several things in these pumps that wear out and die...The stepper motor can also fail..
Only a good test stand run can really figure out what the issue is....High miles is a pretty good indicator of possible issues and point the finger at the pump.

When was the fuel filter last changed ?????


IF/WHEN you remove the IP....Scribe a straight line across the top of the pump flange and the timing cover BEFORE loosening the bolts...
This will allow you to get the pump back very close and things will be in the ball park and close enough to work....You can then check the actual timing and see where you are at.

Good luck
Keep us in the loop...

Pump has around 100k on it. Although my other truck has 250k on the pump and runs like it's brand new (engine has 487k and | haven't done a damn thing to it since changing the IP at 247k, and I think it only needed a PMD at that time but wasn't educated enough yet). I own 5 of these things.

The reason I was asking is because there's a lot of internet results saying the stepper motor will cause that code, and considering | cannot get it to move with a tech2, I figured it might be stuck.

The surging/missing didn't happen all day yesterday and I drove about 200 miles. P0216 stayed on though. Other than that I'm not noticing any other drivability concerns except the engine is slightly louder which I’m attributing to the timing discrepancy.

I did dump atf after the 200 mile drive so we'll see. I also ordered a stepper motor. Figure that's worth a try before changing the IP.

Voltages are fine and I changed the filter about 500 miles ago.

Sounds good
See what the stepper does and go from there....

Replaced the stepper and it resolved the desired/actual timing issues.
closure time still varies between 2.17-2.21ms but I think this pump has always been around that range.

My truck with over 200k on the IP holds steady at 1.8ms, but from what I'm reading, anything under 2.5ms should be acceptable.

The stepper I purchased appears to be of low quality, so I'm sure I'll be replacing it again soon. I may just replace the IP at that point

Sounds good.
Glad you got the issue fixed.