My truck is am early 99 F-350 with 268K BONE STOCK right down to the factory exhaust. Noticed the truck was surging while driving home the other day and it had a rough idle when I came to a stop. Borrowed a scan tool from a friend and pulled the following codes: P1690 (wastegate solenoid), P0381 (glow plug circuit malfunction), P0269 Cylinder 3 Contribution/Balance Fault, and P0284 Cylinder 8 Contribution/Balance Fault.
I did some research and everything I read said it was most likely the CPS. I changed the CPS and cleared the codes. Drove the truck about 30 miles and it ran great but when I did a cylinder balance test it still gave me P0284 Cylinder 8 Contribution/Balance Fault. Drove it today and it ran great for about 20 miles and then it started the surging and rough idle again. I did a full scan, buzz test, and cylinder balance and the only thing I got was P0284 Cylinder 8 Contribution/Balance Fault but after about 5 miles it smoothed out and ran fine again.

 

Do some research but I believe the Grey CPS can give #8 balance faults. Just saying it can send you on a wild goose chase.

1. Condition and level of oil?
2. Condition of batteries and ground connection? Week batteries can cause a lot of issues.
3. Check the wire harness for rubbing over the valve covers. Especially the one over the drivers side. You may need to pop off the valve covers and check the harness as it likes to come loose.
4. Surging makes me feel like it's oil pressure related. While it's idling rough pull the connection to the ICP sensor and see if it helps. Also look inside the sensor for oil. Oil= bad sensor.
5. Another part of the High pressure oil is the IPR valve. If you have access to an Android device you can run Torque App and monitor the sensors I mentioned in real time that could help narrow down your problem. Here is the link to set it up.... https://www.ford-trucks.com/forums/1...-in-bacon.html

 

Thanks snknby123. I installed new batteries and added extra ground cables not too long ago but she still seems to turn over slow and start hard. I plan to change the starter but I will check the other stuff you mentioned.

 

The Ford Grey CPS is indeed known for the cylinder 8 & cylinder 3 codes. I get them intermittent when I run a CCT.

IPR issues can cause rough running and hard starts when hot. Unplugging the ICP sensor is good advice from snknby123. If that doesn't help, an IPR rebuild might be in order. Being able to monitor PIDs while the issue is occurring would be a big plus.

 

My slow crank times were corrected after I swapped out the starter. I installed the short body one that is supposed to be like a high output version.

Here is a great link on a starter replacement.. https://www.ford-trucks.com/forums/1...sd-w-pics.html

 

When I changed my CPS I installed a Duralast (part #SU2159), I think they are made by Wells. I've still had the surge & rough idle issue and #3 & #8 cylinder codes since then. The truck starts fine when it's warm but I did notice this morning that it starts easier if I give it a little throttle when its cold. That could be because it cranks over kinda slow if I don't plug it in at night. Oil level is good and it only has about 2000 miles on it since it was changed. HPOP oil level is good also. ICP sensor looks good (no oil leaking out of it).
1 other thing to note, once the surging & rough idle starts occurring it continues until I shut the truck off. If I shut the truck off and re-start it the surging & rough idle goes away, maybe for a few miles or maybe for a few days.

 

It sounds like something is "sticking". I've heard of a "sticking" IPR before, but I don't know how to describe what that means. The fact that it will run rough and continue until you shut it off and restart leads me to think something is getting stuck, and then possibly resetting itself until just the right circumstances, when it sticks again.
I wish someone else would chime in, as I've never had an IPR apart so I'm not even sure if this possible. But it sounds realistic, no?

 

I read a thread where several people had problems with a certain brand of Cam Pos Sensor acting up & causing problems when the windshield wipers are on the delay setting. After reading that anything seems "reasonable" with these trucks. lol

 

Lol! Yes, the CPS and windshield wipers share a grounding point on these trucks. Aftermarket sensors have been to known to cause negative reactions in the rain.
Radio waves, such as around large cell towers can interfere with aftermarket CPS and ICP sensors as well.