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7.3 surging problem under load
I have a 2000 7.3 F-350 6-speed with 195k miles. It is bone stock, no chip, and I believe original injectors. I'm having a couple problems with it, they could be related, but I'm not sure. Let me start off by saying that I just replaced the IPR and ICP with good Motorcraft parts. I thought this was the problem but didnt solve it.
1) When the engine is cold and hasn't been running after sitting all night, it is very rough idle and doggy, shakes real bad. You have to take off in Low gear so it doesn't die. Once you drive down the road for a while, and you drive it somewhat hard, it is like the flip of a switch and clears out and runs just fine. It will be just fine for the rest of the day and until it sits overnight.
2) The other problem is when driving down the road, and get rolling to at least probably 35 mph, the truck will start surging and jerking. If you get into the throttle it usually smoothes out and runs fine. But as soon as you ease off the throttle it starts surging and jumping and jerking again, until you let off or hammer on the throttle. It tends to be worse when we have our 36' enclosed gooseneck trailer behind it, which is a good bit of weight. But it still will do it without the trailer.
I scanned it with a good snap-on scanner, and it gave me the codes:
-P0107 map/BP sensor circuit low
-P0118 ECT circuit high input
-P1249 wastegate control valve
-P0475 exhaust pressure control
The reason for the wastegate code I believe is because I unplugged the wire that's on the front of the turbo mount I believe it was because the wastegate would stick open driving down the road and hiss real bad. I need to clean the tube that I read about on here and hook the wire back up.
The map sensor code is what my thoughts are right now, but I also thought and have read a lot about the Cam Position Sensor. Could it cause these problems?
And I also thought about the throttle position sensor.
Any ideas guys? Thanks in advance!