Jeff_E Posted September 16, 2008 Share Posted September 16, 2008 Well I've got one from another dealer that gave up on it after replacing just about everything. It is a 99 F350 7.3, and I have most of the problems figured out, but I have a hard fault P0476 (exh pressure control valve range/performance) and a continuous code P0478 (exh pressure control valve high input) The previous dealer already threw the following parts at it: injectors, pedestal, ebp sensor, ebp tube, used engine, and on, and on. I've been following the PPT for the P0476, up to-and including removal of turbo and pedestal to inspect the butterfly valve and linkage adjustment. The adjustment was way off, but I corrected it and reinstalled everything. Guess what, I still have the same hard fault P0476 /forums/images/%%GRAEMLIN_URL%%/banghead.gif My ebp readings seem normal, the valve moves during the KOER, but I'm running out of ideas. Any help would be appreciated. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted September 16, 2008 Share Posted September 16, 2008 If she runs good and makes rated boost then punt it. /forums/images/%%GRAEMLIN_URL%%/grin.gif Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted September 16, 2008 Share Posted September 16, 2008 I won't disagree with Brad, 'cause this DTC doesn't turn on the money light. Has the PCM been reflashed? Are there any non-OE modifications? /forums/images/%%GRAEMLIN_URL%%/grin.gif Quote Link to comment Share on other sites More sharing options...
Jeff_E Posted September 16, 2008 Author Share Posted September 16, 2008 I have already reflashed the pcm and the code still sets, the only aftermarket thing I found was a K&N air filter. I'm sure I've seen these codes on 7.3's in the past, and never really figured out the root cause so punting on this one definitely crossed my mind. I've been putting extra effort in to this one though, because it was sent over from the Other Ford store in my dealer group after they repeatedly failed to figure out what's going on. (The owner of the truck actually thinks his truck is at the other dealership 30 miles away /forums/images/%%GRAEMLIN_URL%%/eeeesh.gif) I spent all morning on it and found several problems ie: 5 of the 8 glow plugs are open, the intake air heater element is open. I'm sure that replacing these things will at least improve the low power cold condition of this truck, but I'm kinda under the microscope on this one, and our sister store is depending me to put out their fire discretely - so my stress level is pegged on max. When I cold drove it this morning... besides the massive amounts of smoke, it just felt like the ebp wasn't opening like it is supposed to when the throttle was pressed, so I'm worried about that due to these ebp related codes that keep setting. It runs fine when warm. I'll let you guys know how it cold starts and runs tomorrow, but till then, if you guys have any other suggestions I'm all ears. Thanks, ~Jeff Quote Link to comment Share on other sites More sharing options...
Rickster42 Posted September 16, 2008 Share Posted September 16, 2008 Jeff, does baro & ebp match koeo? Does the ebp go up on accell? You said the epr linkage moves on koer test right? If those things are ok I would forget about the p0476. Saw it many times and mostly led to nothing... The p0478 could be nothing also, as key may have been cycled with ebp disconnected as parts have been replaced recently(hard to say yet..) Eot low? below certain temp(I forget now what it is but it is quite warm..) that epr comes on alot under low power cruise. Fixed quite a few with a thermostat. Smoke bothers me though... Quote Link to comment Share on other sites More sharing options...
Jeff_E Posted September 17, 2008 Author Share Posted September 17, 2008 Yup, Static EBP-MAP-Baro all within .3psi of 14.2 EBP does increase with acceleration EPR linkage does move during a KOER test, however I don’t know if it actually makes a full sweep or not, nor do I know if it’s supposed to during a KOER, and I will add that with the engine off, it is all the way open (tang against its stop), but while running it is slightly off the stop, but not nearly closed. As of now, the linkage is adjusted properly because I just did it myself per the instructions in the pedestal tsb… It takes 10 pounds of force to cause the .010 feeler gauge to drop from between the tang and the stop which is spec. I found the ssm listed below. It states the EBP should open when the accelerator pedal is depressed, but based on my test drive this morning it sure didn’t feel like that was happening. The truck just fell on its face. As far as the smoke is concerned, I’m hoping that having 8 working glow plugs and a working intake air heater will alleviate that part. I’ll find out tomorrow. The truck runs beautifully once it warms up, but I will check the operating temp tomorrow to see if the thermostat is operating properly. Quote: 16697 1994-2003 F-SUPER DUTIES, 1995-2003 ECONOLINE AND 2000-2003 EXCURSION 7.3L DIT ENGINE MAY EXHIBIT LOWER POWER WHEN COLD, AND AN AIR RUSHING NOISE NORMAL OPERATION - EXHAUST AIR RUSH NOISE AND LOWER POWER. SOME 1994-2003 F- SUPER DUTIES, 1995-2003 ECONOLINE AND 2000-2003 EXCURSION WITH 7.3L ENGINE MAY EXHIBIT LOWER POWER WHEN COLD AND AN AIR RUSHING NOISE. THE TURBO CHARGER EXHAUST IS RESTRICTED BY THE EBP TO HELP INCREASE ENGINE COOLANT TEMPERATURE QUICKER FOR CAB HEAT. THIS IS CONTROLLED BY THE PCM & THE EBP REGULATOR LOCATED IN THE TURBOCHARGER PEDESTAL. THE EBP DEVICE WILL OPEN WHEN THE ACCELERATOR PEDAL IS DEPRESSED CAUSING EXHAUST BACK PRESSURE TO INCREASE. WHEN EXHAUST BACKPRESSURE DECREASES OR THE VEHICLE IS AT A STEADY STATE THE EBP REGULATOR CAN/WILL ACTIVATE THE EBP DEVICE AGAIN EVEN DURING HIGHWAY DRIVING AS LONG AS THE EOT TEMP IS BELOW SPECIFICATIONS. PCM CONTROLLED ON THE FOLLOWING PARAMETERS: IAT BELOW 10C(50F) & EOT BELOW 70C(158F) EFFECTIVE DATE: 03/17/2003 In other interesting news, I Googled this problem and found that not only are there many people experiencing these concerns, but there exists an entire array of aftermarket devices which have been developed to defeat the EPR system. CLICK HERE And scroll down to the last 6 items. Although they won’t show up in time to help me, I did place such an order from that site, so the next time I have a 7.3 with a similar concern I can experiment. (Insert Jim bitching here) /forums/images/%%GRAEMLIN_URL%%/grampy-jim.gif Now however, there is another issue. This vehicle is equipped with a junkyard engine, so I don’t really know if the PCM calibration is actually correct for the specific 7.3 in this truck anyway. I found a list of calibration tear tag numbers and their descriptions for 99 model year trucks, and there are calibrations for “warm winter” and “cold winter” package trucks. Does anyone know if the “warm winter” package is simply a non EPR equipped truck, and if so, would blind flashing it with a “warm winter” calibration deactivate EPR and eliminate my problem???????? Keep the input coming fellas, my brain hurts as I prepare for battle tomorrow /forums/images/%%GRAEMLIN_URL%%/crybaby2.gif Quote Link to comment Share on other sites More sharing options...
DwayneGorniak Posted September 17, 2008 Share Posted September 17, 2008 Just another little side note or hopefully a helpfull pointer: When I adjust the back pressure linkage, I back them off from what they say in the book. Meaning that I don't like to see them close as much they want them too. I have seen them stick shut from rust and carbon. And it seems to have been succesfull for me. /forums/images/%%GRAEMLIN_URL%%/2cents.gif Quote Link to comment Share on other sites More sharing options...
Rickster42 Posted September 17, 2008 Share Posted September 17, 2008 I would just unplug the epr solenoid and r/test it cold and see quickly if I was chasing my tail or not.. I`m a bit surprised that it doesn`t have cold start issues with that many glow plugs out - but that may be a good thing as far as base engine goes... Try buzz test cold - see if any sound different. check mfdes cold idling. Open the fuel drain when idling cold - does it run better? = bad injector/s Run a cyl cont test cold ( with a resistor in the eot connector to fool pcm so that it will run a cont test cold)I will have to measure my resistor cause I forget values.. As you can see I`m thinking fuel/injectors, but it`s early yet. Bruce has alot of great tips on these, perhaps he will chime in... Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted September 17, 2008 Share Posted September 17, 2008 I would just unplug the epr solenoid and r/test it cold and see quickly if I was chasing my tail or not.. I`m a bit surprised that it doesn`t have cold start issues with that many glow plugs out - but that may be a good thing as far as base engine goes... Try buzz test cold - see if any sound different. check mfdes cold idling. I look at MFDES hot idling, and like to see it below 12 grams. Open the fuel drain when idling cold - does it run better? = bad injector/s Run a cyl cont test cold ( with a resistor in the eot connector to fool pcm so that it will run a cont test cold)I will have to measure my resistor cause I forget values.. IIRC, a 2K resistor gets you 218F. As you can see I`m thinking fuel/injectors, but it`s early yet. Bruce has alot of great tips on these, perhaps he will chime in... I'd backprobe the EBP and see what voltage you get during the KOER vs. what you get commanding the EBP closed. There's a threshold that must be reached during KOER. You say it blows a 476 immediately on KOER, try plugging a spare EBP in the harness and blowing into the bottom of it with a rubber tip blow gun when the KOER is running to trick it into thinking the EBP is causing good backpressure. Do you hear the "vacuum cleaner" noise when KOER is running? You're going to a lot of trouble for a ghost code....... /forums/images/%%GRAEMLIN_URL%%/coffee.gif Quote Link to comment Share on other sites More sharing options...
Jeff_E Posted September 17, 2008 Author Share Posted September 17, 2008 Well, I cold started it this morning and all was good, no smoke, and had much more power. It's amazing what working glow plugs and properly adjusted linkage can do. I ran the KOER again after my road test, and the first time it passed. I ran it again and the second time it failed with the P0476 again. Time to drop back 30 and punt. Thanks for all the help guys! /forums/images/%%GRAEMLIN_URL%%/cheers.gif Quote Link to comment Share on other sites More sharing options...
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