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2000 f350 is having a surging at idle problem. I have read through alot of threads and can't seem to come up with a solution. It's not surging drastically but when my icp gets to low I'm getting a annoying vibration in the engine. The vibration is another issue but I need to try and stop the surging problem first. It's going up and down 560 and 640 ( sometimes more),and definitely noticable in the rpms. I have a new motorcraft icp and ipr, both with alliant pigtails soldiered in. Injectors and o-rings only have about 3,000 miles on them and I didn't have the surging after I installed the injectors. It seems like either the icp or ipr isn't working properly (maybe bad out of the box), so thinking I will replace 1 of those (again). if I unplug the icp while the motor is running nothing changes other than I see on forscan that the icp goes straight to 745 since that is the default value. So being that nothing changes you would usually change the icp BUT, being that the pcm is seeing the correct values, would that lead me to replace the ipr? Is there anything else I'm forgetting here? Just trying to avoid having to buy both parts if possible since I just changed them 6 months ago. Thanks for any help
Before you drop 2 bills on another new IPR, I'd suggest some testing. Try unplugging both injector harnesses and crank the engine while monitoring ICP. Fuel system issues can cause several similar problems as hpo issues, and since the pcm can't monitor the fuel, it won't give any codes for it.
Before you drop 2 bills on another new IPR, I'd suggest some testing. Try unplugging both injector harnesses and crank the engine while monitoring ICP. Fuel system issues can cause several similar problems as hpo issues, and since the pcm can't monitor the fuel, it won't give any codes for it.
My fuel gauge reads a steady 70 psi but I will try unplugging the injector harness , good call. Am I basically watching to see if icp builds pressure quickly or if it holds a steady pressure?
Can you post several seconds of idle RPM, FUELPW, ICP, IPR% in a FORScan log or graph? One with ICP plugged in, and one with ICP unplugged, to see how IPR% behaves in each case.
I'm still very much learning how the data in these logs relates to the actual symptoms we are experiencing with these engines, so would like to see what your sensors are reporting.
Does this surging happen more often when the engine is cold or up to operating temp?
725psi is more typical of an unplugged ICP - 745 is different, so wondering why that is. Might be nothing.
From the link below: "There should be a noticeable difference in idle when you unplug your ICP." Makes me wonder about the ICP. Its hard to know for sure, darn it, especially on these slight surge issues.
My fuel gauge reads a steady 70 psi but I will try unplugging the injector harness , good call. Am I basically watching to see if icp builds pressure quickly or if it holds a steady pressure?
You want to see injector duty cycle hold 64% and ICP 3000+ psi pretty quick. If yes, then the pump, IPR, and injector o-rings are doing their jobs. If no, then there is a problem and we start doing more tests.
70 psi fuel pressure is the top of spec, but I'd be looking close for possible leaks. Any where liquid can get out air can get in, and our injectors don't like air.
Can you post several seconds of idle RPM, FUELPW, ICP, IPR% in a FORScan log or graph? One with ICP plugged in, and one with ICP unplugged, to see how IPR% behaves in each case.
I'm still very much learning how the data in these logs relates to the actual symptoms we are experiencing with these engines, so would like to see what your sensors are reporting.
Does this surging happen more often when the engine is cold or up to operating temp?
725psi is more typical of an unplugged ICP - 745 is different, so wondering why that is. Might be nothing.
From the link below: "There should be a noticeable difference in idle when you unplug your ICP." Makes me wonder about the ICP. Its hard to know for sure, darn it, especially on these slight surge issues.
Oil only has 3000 miles on it and is full. Yes I would be happy to post some logs, unfortunately I am not very good at graphs. The surging is there when cold but much more noticable once warmed up. The surging has progressively gotten worse over the past month, it is still not as drastic as armylifers recent thread but definitely noticable. The 745 number I was going off of memory so it very well could be 725 but I will get the true numbers in a log . I was surprised when I there was no change in idle when unplugging the icp as well, it just seems odd because the pcm seems to be seeing the correct values from the icp. There is another weird issue going on I'm hoping the graph may reveal, especially shortly after start up the engine sounds like it has a load on it and then all of a sudden it frees up and runs normally like there is no load. It's not the a/c as I have tried figuring this out when the a/c is off, any idea of what else would be causing a intermittent load on the engine like that? I do have a lower generator code that keeps coming back, but would the lower generator really cause that much of a "load" sound on the engine? It is brand new also.
Unplug the Fuel bowl heater. Caused my surge, without popping the #30 underdash fuse which is more common
Thanks wes444 but I already have the heater unplugged. I never thought the fuel bowl heater would cause surging but these trucks definitely do some weird things. Like the 3rd brake light affecting the cruise control
You want to see injector duty cycle hold 64% and ICP 3000+ psi pretty quick. If yes, then the pump, IPR, and injector o-rings are doing their jobs. If no, then there is a problem and we start doing more tests.
70 psi fuel pressure is the top of spec, but I'd be looking close for possible leaks. Any where liquid can get out air can get in, and our injectors don't like air.
Sounds good I will check that out. As far as the fuel system, I went through everything about 6 months ago when I did the h/h mod but I will double check
The good thing about the new PID charting tool https://www.ford-trucks.com/forums/1...d-version.html is you don’t have to be good at graphs. If you can get the data logged with the requested PID’s, we can help you get it graphed. @Sous and @BWST are very good at this! I’m even passable now. Once graphed, the smart guys here can get your issues pinned down.
Oil only has 3000 miles on it and is full. Yes I would be happy to post some logs, unfortunately I am not very good at graphs. The surging is there when cold but much more noticable once warmed up. The surging has progressively gotten worse over the past month, it is still not as drastic as armylifers recent thread but definitely noticable. The 745 number I was going off of memory so it very well could be 725 but I will get the true numbers in a log . I was surprised when I there was no change in idle when unplugging the icp as well, it just seems odd because the pcm seems to be seeing the correct values from the icp. There is another weird issue going on I'm hoping the graph may reveal, especially shortly after start up the engine sounds like it has a load on it and then all of a sudden it frees up and runs normally like there is no load. It's not the a/c as I have tried figuring this out when the a/c is off, any idea of what else would be causing a intermittent load on the engine like that? I do have a lower generator code that keeps coming back, but would the lower generator really cause that much of a "load" sound on the engine? It is brand new also.
the load at startup could very well be the alternator playing catch up because of a parasitic draw. I don't think there all that uncommon on these trucks. I have one caused by the factory head unit. It draws 5 amps even when it's powered down and the ignition is off. The test for parasitic draw is pretty simple I'll go ahead and post a link in case you're not familiar with it
jstihl was having some issues identifying the log files on his local machine, so I offered to help him out. He sent the log files to me via email and I have attached the "jstihl ICP Plugged In" chart and the "jstihl ICP Unplugged" chart. I have also snipped a bit of each chart and pasted them below.
This image is from the "jstihl ICP Plugged In" chart.
This image is from the "jstihl ICP Unplugged" chart.
Just looking at the chart and the PID's that were logged, jstihl I need you to double check your settings and selected PID's against what I have indicated in the instructions for creating a log.
Not a big deal, but if you can pay close attention to page two in order to set the csv delimitator to "comma" as shown in the instructions, that would help for future logging charts.
Proceed down to page 9 where I have indicated some of the PID's that are critical to select when logging data. A couple of them are a bit tricky, but they have all been identified very specifically on page 9. In my opinion, I believe this is why your EOT end EBP were all over the place in the charts. Once we make sure the correct PID's have been selected, we can start to pinpoint the problem.
Thank you for taking the time to chart these logs sous, I do appreciate it! I will double check but I'm almost positive it was on the comma setting. I will also go through the instructions and figure out what I did wrong. I did notice the engine oil temp was very rapidly going all over the place when rewinding through the log slowly but did not notice this at all when the log was being recorded.
Would you like me to log all the pids that are on page 9 of the instructions?
. I was surprised when I there was no change in idle when unplugging the icp as well, it just seems odd because the pcm seems to be seeing the correct values from the icp. There is another weird issue going on I'm hoping the graph may reveal, especially shortly after start up the engine sounds like it has a load on it and then all of a sudden it frees up and runs normally like there is no load. It's not the a/c as I have tried figuring this out when the a/c is off, any idea of what else would be causing a intermittent load on the engine like that? I do have a lower generator code that keeps coming back, but would the lower generator really cause that much of a "load" sound on the engine? It is brand new also.
