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Early 1999 F-350 7.3. For a while it would seem sluggish going down the road like you were pushing a weight down the road. This was with no trailer though. So I used Forscan to read codes and monitor PIDS, and I have attached 2 pictures of the PIDS. Then I realized it could be the EBP sensor causing the problems because of what I read on here and other forums. So I unplugged the EBP sensor and sure enough it felt like it had more power again. So this weekend I decided to clean the EBP tube and sensor then plug it back in. Both tube and sensor appeared to be ok, tube did not appear to have any leaks in it. When plugged in, it has very sluggish acceleration and you can hear the loud hiss sometimes at low RPM's. Then unplugged it goes away and has plenty of power again. Is there a way to test the EBP sensor? Would something else be causing the EBP valve to close, something like the EOT sensor or ECT sensor?
The EBPS (tube and sensor on front of motor) has nothing to do with the operation of the EBPV (the restrictor valve on the back of the turbo).
The reading on the EBPS if you are monitoring the PID should be a PSI rating very closely following the MAP sensor reading. It is basically reading the exhaust drive pressure that is bottling up behind the exhaust side of the turbo. The sensor I think looks for this number to get too high compared to the MAP reading and the PCM trims the fuel back a little, which would make sense as many guys who replace a cracked tube and bad sensor report an increase in MPG.
The EBPS (tube and sensor on front of motor) has nothing to do with the operation of the EBPV (the restrictor valve on the back of the turbo).
The reading on the EBPS if you are monitoring the PID should be a PSI rating very closely following the MAP sensor reading. It is basically reading the exhaust drive pressure that is bottling up behind the exhaust side of the turbo. The sensor I think looks for this number to get too high compared to the MAP reading and the PCM trims the fuel back a little, which would make sense as many guys who replace a cracked tube and bad sensor report an increase in MPG.
I believe you're wrong on both statements. The sensor is there specifically to limit the EBPV being closed when it shouldn't be. The fuel is limited by boost pressure and not by exhaust pressure. From what I read from a supposed engineer at International, the EBPS is only for controlling the EBPV and does nothing else. Do trucks made without an EBPV have an EBPS? If they do then the EBPS is obviously doing something else, if not it lends more evidence to it only existing to control the EBPV.
Early 1999 F-350 7.3. For a while it would seem sluggish going down the road like you were pushing a weight down the road. This was with no trailer though. So I used Forscan to read codes and monitor PIDS, and I have attached 2 pictures of the PIDS. Then I realized it could be the EBP sensor causing the problems because of what I read on here and other forums. So I unplugged the EBP sensor and sure enough it felt like it had more power again. So this weekend I decided to clean the EBP tube and sensor then plug it back in. Both tube and sensor appeared to be ok, tube did not appear to have any leaks in it. When plugged in, it has very sluggish acceleration and you can hear the loud hiss sometimes at low RPM's. Then unplugged it goes away and has plenty of power again. Is there a way to test the EBP sensor? Would something else be causing the EBP valve to close, something like the EOT sensor or ECT sensor?
If it's cold enough that your EBPV is being closed and the EBPS isn't working then it would definitely have a lack of power.
On a cold engine, as in setting overnight, KOEO the EPB, MAP and BARO PID’s should read within.5 of each other.
When I cleaned my EBP sensor and tube I didn’t see any change in my EPB PID readings. I ordered a new sensor from clay at Riff Raff Diesel and my readings are now all within .1 of each other. BTW when reading these three PID’s make sure you are in stock tune as some tuners modify these readings through the tunes.
The EBPS (tube and sensor on front of motor) has nothing to do with the operation of the EBPV (the restrictor valve on the back of the turbo).
The reading on the EBPS if you are monitoring the PID should be a PSI rating very closely following the MAP sensor reading. It is basically reading the exhaust drive pressure that is bottling up behind the exhaust side of the turbo. The sensor I think looks for this number to get too high compared to the MAP reading and the PCM trims the fuel back a little, which would make sense as many guys who replace a cracked tube and bad sensor report an increase in MPG.
Originally Posted by '88 E-350
I believe you're wrong on both statements. The sensor is there specifically to limit the EBPV being closed when it shouldn't be. The fuel is limited by boost pressure and not by exhaust pressure. From what I read from a supposed engineer at International, the EBPS is only for controlling the EBPV and does nothing else. Do trucks made without an EBPV have an EBPS? If they do then the EBPS is obviously doing something else, if not it lends more evidence to it only existing to control the EBPV.
Going to have to go with Brandon on this one. The EBPV is controlled based on temps and nothing more. It is there to help the engine warm up quicker.
Going to have to go with Brandon on this one. The EBPV is controlled based on temps and nothing more. It is there to help the engine warm up quicker.
What exactly does the EBP sensor do then? I'm still confused as to what it does and why unplugging it causes the EBP valve to stay open. It seems like the PCM is taking the pressure reading from the EBP sensor along with the oil temp. sensor and then decides whether or not to close the EBP valve on the turbo. So I guess that if the oil temp AND the exhaust pressure are both low enough, then the EBP valve closes, but if one of the two is high enough then it will stay open. So as an example, if the oil temp is low but you are driving and accelerating the engine, then it sees that the exhaust pressure is high enough to warrant opening the EBP valve, as to not hamper engine performance while driving. But if you let the engine idle back down again, either in park or sitting at a stop light, then it will close again, so as long as the oil temp is still low enough. I thought I read somewhere that it primarily works off of oil temp. I may be wrong but that is how I understand it.
What exactly does the EBP sensor do then? I'm still confused as to what it does and why unplugging it causes the EBP valve to stay open. It seems like the PCM is taking the pressure reading from the EBP sensor along with the oil temp. sensor and then decides whether or not to close the EBP valve on the turbo. So I guess that if the oil temp AND the exhaust pressure are both low enough, then the EBP valve closes, but if one of the two is high enough then it will stay open. So as an example, if the oil temp is low but you are driving and accelerating the engine, then it sees that the exhaust pressure is high enough to warrant opening the EBP valve, as to not hamper engine performance while driving. But if you let the engine idle back down again, either in park or sitting at a stop light, then it will close again, so as long as the oil temp is still low enough. I thought I read somewhere that it primarily works off of oil temp. I may be wrong but that is how I understand it.
I may have opened my mouth a little too quickly. I know low temp activates the ebpv system and that others have had low mileage issues with a bad ebp sensor. I've always assumed the 2 were separate systems. Now I have some research to do.
From the article
If your 7.3 EPB sensor's bad or malfunctioning, it can cause sluggish performance. A bad EPB 7.3 sensor can cause sluggish performance buy telling the exhaust back pressure valve at the turbo outlet to close at times that it should not close.
I still have more reading to do. You would think if the engine was at operating temp the valve should not close at all. I could see the defueling part but not the valve opening.
The exhaust back pressure valve on the turbo I am pretty sure operates off the EOT sensor data (cold oil=close the valve to help warm the motor up. Hot oil = open the valve)
I am not sure if the PCM uses the EPB sensor data to effect valve operation, but it is possible. (Whoever designed the powertrain control module would know that.)
As for what the PCM actually does with the EBP sensor data I am not 100% certain either. Everything I have ever read suggests it affects fueling trims in some way. The truck will run with the tube completely missing or failed. Mine had a crack/hole in one of the bends and would not hold any pressure at all if I put my finger over one end and blew into the other. Other people have suggested it did improve fuel economy noticeably when they replaced the tube and sensor. (I didn't notice anything drastic when I did, but, maybe a little. Probably depends on how hard the truck is driven and mine is not driven very hard)
What exactly does the EBP sensor do then? I'm still confused as to what it does and why unplugging it causes the EBP valve to stay open. It seems like the PCM is taking the pressure reading from the EBP sensor along with the oil temp. sensor and then decides whether or not to close the EBP valve on the turbo. So I guess that if the oil temp AND the exhaust pressure are both low enough, then the EBP valve closes, but if one of the two is high enough then it will stay open. So as an example, if the oil temp is low but you are driving and accelerating the engine, then it sees that the exhaust pressure is high enough to warrant opening the EBP valve, as to not hamper engine performance while driving. But if you let the engine idle back down again, either in park or sitting at a stop light, then it will close again, so as long as the oil temp is still low enough. I thought I read somewhere that it primarily works off of oil temp. I may be wrong but that is how I understand it.
It might work that way. If the PCM is seeing high enough pressure from the EBP sensor it would make sense that it would override the EOT data and cause the valve to open. probably not a great idea to be pushing the motor that hard with the oil still cold though would be my practical observation. When the exhaust drive pressure starts to drastically spike higher than the intake manifold pressure that means you're really womping on it.
