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Okay... 03 excursion 7.3 diesel... I have an issue... If I'm on the highway and I come off the accelerator pedal and coast then apply the accelerator pedal again I get no response until I slowly apply the accelerator 2 or 3 times then all the sudden I get a burst of acceleration and lots of black smoke out my tail pipe... Thinking this was my sensor in the accelerator pedal I replaced it with a new Ford unit and still have the problem... I also replaced the icp and fpr with Ford parts recently for a stalling issue at idle... This is a pretty modified vehicle.. All mods in my description... Thanks for your time in responding and your ideas!
You'd need to have Forscan running while you replicate the issue. Have all the usual PID's loaded as well as APP and IVS(idle validation switch), maybe the brake pedal switch also. Once you catch it in the act you can save the file and load it here if the culprit doesn't show itself out right. We can have a look at the data and figure something out.
okay so ive done some data logging with my auto enginuity scanner and had some interesting findings, the problem only occurs above about 67 mph, it only occurs on deceleration after an acceleration above 67... upon application of throttle during this decelaration i have no throttle response for atleast 5 seconds, modulating the throttle does nothing, i have to let the truck coast then i get the ability to accelerate back.. generally the truck decelerates to about 60 before i get the pedal back. ive attached my AE logs and you can see that the injector control pressure duty cycle maxxes out and the ICP and ICP volts stay tanked. The orange line shows me modulating the throttle to try to get acceleration back then with a big puff of black smoke i regain the ability to accelerate again assumingly because my injector duty cycle is pegged at max. after driving the truck for a while and getting logs it also through some check engine lights. p1209 injector control pressure peak delta test fault; p1211 injector control pressre highter/lower than desired. i provided the log and another copy where I circle the episodes in the blue and ive included the CEL log. So far Ive replaced the pedal assembly, two icp sensors and the IPR valve, all genuine ford parts. With this log it appears that the truck is calling for injectors to open with the application of the accelerator pedal but the icp is showing low oil pressure and volts. Am i correct in interpreting this as the hpop is falling on its face after any accelerations above 67mph. Maybe it just cannot keep up with the bigger injectors? Any other ideas? I have another fuel pressure gauge on order as mine has failed. Once i have this i can confirm that i have fuel pressure during these episodes, the bosch and fass pumps are fairly new. Any ideas on my interpretation would be great, anyone who knows or has any ideas here would be really helpful. circled areas are when the issue was happening
Normally I’d guess this as an IPR issue but you’ve already replaced it and it only occurs after being at speed. Strange indeed.
Does it act the same with the ICP disconnected? It will use the default tables for ICP and ignore the supposed low pressure.
Have you checked the IPR wiring way back into the harness? Could have a short where it’s commanding % but it’s not getting to the solenoid.
The wiring seems to be intact... the old connector on the IPR did look kinda janky... I replace both the ipr and icp pigtails with ford pigtails and soldered the connections. I'll try disconnecting the icp and see what happens.
If I am reading this right, your IPR duty cycle is maxed out and your ICP is not keeping up. Your HPOP may be on its way out. The lag after high speed cruising may be the HPOP reservoir emptying out as the leaky HPOP attempts to keep up with commanded ICP. The APP seems to be reading okay so it's not a potentiometer dropout.
If I am reading this right, your IPR duty cycle is maxed out and your ICP is not keeping up. Your HPOP may be on its way out. The lag after high speed cruising may be the HPOP reservoir emptying out as the leaky HPOP attempts to keep up with commanded ICP. The APP seems to be reading okay so it's not a potentiometer dropout.
Could it be that the LPOP is not filling the reservoir fast enough to keep up with the HPOP or is it more likely that its an issue with the HPOP?
What is the best way to go about diagnosing this issue? I don't want to throw parts at it but the LPOP is relatively cheap and easy to replace. a definitive diagnosis would be better as I've already spent a lot of money replacing sensors.
okay, ive done some stuff, i had a riffraff hpop reservoir spacer, i installed that thinking maybe the hpop was draining the reservoir on WOT pulls, after a nice long lengthy pull and a nice speeding ticket i found that it still has the problem, i also took the plug off of the top of the hpop reservoir after installing the spacer and oil went all over the place so it seems like the LPOP is functioning fine. Seems like its one of two things, either a bad NEW IPR valve from ford or my HPOP is on the outs, of course the two most expensive parts to replace. Thoughts? Your time and feedback is much appreciated!
Can you post your raw data (CSV file would do it). I'd like to graph and scroll through it to better see what's going on. Would like RPM if you have it, in addition to ICP, ICP duty cycle, pedal position and speed. Other PIDs that can be helpful here are mass fuel desired MFDES, Manifold gauge pressure MGP, BARO and MAP.
When this lack of pedal response occurs, do you get any other lights on the dash, like WIF or ABS? Wondering if the PCM is resetting due to a short. The harness over the driver's side valve cover shorting out can cause this - how do the wires look in that area?
Do you have an auto? Have you done the chaffed wire fix in the shift handle? That can cause the PCM to reset for a few seconds as well.
