EGR Bypass constant reading of 100%. Poor acceleration

[ImNoExpert]

It depends on what sort of warranty you have with it and how long you've had it. I mean you have the evidence that the filter is blocked / end of life, so will soon be undriveable in this state.

Be careful around exclusions relating to the exhaust - as the DPF should be looked at as a separate item to an exhaust system. It would seem if original, that it is at end of life.

OK, Marc thanks once again for stepping in.

I'm currently trying to find the numbers relating to the exhaust/DPF pressure and what they should read. I have always remarked that there seemed very little pressure coming from the tailpipe.

It's not so much a Warranty Issue as a Seller Issue. He can't sell me a £6k van that has an almost blocked DPF, Slipping Clutch, Leaking Injector Seal, Cabin Blower not connected, Exhaust resting on rear axle afterMot, Drop Link busted and un-disclosed crash damage at the front.

I've been collecting the evidence for 3 months and all of it from Day 1 of driving away. My trouble has always been the lack of Engine Light or Codes, which I think is quite suspect. To be this slow and 91% blocked suggests there should have been some kind of message by now?

My next step is to confirm the Back Pressure and consider a Clean On the vehicle. However, I'm not convinced a Clean will sort it.


If you could tell me what the pressure should be I'll greatly appreciate it. Thanks.

[GiveMeABreak]

I don't know if I'll have that data for this vehicle, but pop your VIN up (automasked on post submission) and I'll have a look.

[ImNoExpert]

Thanks. I'd be happy to make a donation to the forum.

VF3**************[VIN obfuscated, can be read by forum staff]

[GiveMeABreak]

This is based on the DW10CTED4 engine which is more or less the same:

This is how the particle filter differential pressure sensor operates and the pressure range is further on.

(1)Particle filter differential pressure sensor.
"b" Pressure take-off downstream of the particle filter.
"c" Pressure take-off upstream of the particle filter.
"d" Piezoresistor sensor (or accelerometer).
"e" Integral electronics.
The sensor is a passive sensor with integral electronics, supplied by the engine ECU ( as +5V).
The piezoresistor sensor receives the pressure upstream of the particle filter on its upper face and the pressure downstream of the particle filter on its lower face.
The difference between the pressure upstream and the pressure downstream of the particle filter causes the resistance of the piezoresistor sensor to vary.
Depending on the resistance of the piezoresistor sensor, the integral electronics generates a voltage that is proportional to the difference between the pressure measured upstream and the pressure measured downstream of the particle filter.

"U" Output voltage of the particle filter differential pressure sensor.
"dP" Difference in the pressure measured between upstream and downstream of the particle filter.
The output voltage of the particle filter differential pressure sensor is proportional to the difference in pressure between upstream and downstream of the particle filter.

"B" Percentage error.
"T" Ambient temperature in which the sensor is operating.
The graph shows the percentage error as a function of the ambient temperature of the particle filter differential pressure sensor.
The least precise ranges of use (from ± 4 % to ± 2%) are between -30°C and - 15°C, and between + 100°C and +135°C.
The most precise range of use (± 2 %) is between -15°°C and + 100°C.

Designation	Value
Supply voltage	5 ± 0,25V
Exceptional supply voltage	6V
Maximum supply current	20 mA
Range of differential pressure measured	0 ? Differential pressure measured ? 100 KPa
Maximum pressure admissible without irreversibly damaging the operation of the sensor	Maximum pressure upstream: 220 Kpa
" "	Maximum pressure downstream: 100 Kpa
Maximum pressure admissible without mechanically destroying the sensor	Pressure upstream: 310 Kpa
" "	Pressure downstream: 110 Kpa
Environmental temperature in use	- 30 ? temperature in use ? +135°C
Environmental temperature not in use	- 40 ? temperature in storage ? +145°C
Maximum temperature of exhaust gas entering the sensor	125 °C
Output impedance	<10 ohms

[ImNoExpert]

Thanks @Marc.

3 months ago the back pressure was showing as pretty high (can't remember the figure) but the mobile mechanic whom specialises in Hydrogen Carbon Cleaning remarked with concern.

However, we completed a half hour CC and the it worked a treat, though not for my acceleration issue. Before the CC it would struggle to rev up to or past 3000rpm. After the clean it freely rev'd to 4k, but it was still very slow. We never did another test afterward as we assumed all the problems were to do with the leaking injector seal on 1 cylinder. Using my FAP app I can see Live data of the FAP PRessure which is showing a max of 211mbar which i've translated as to around 3psi. From what I can gather this is normal pressure?

This brings me to todays question. I have done a very rudimentary Smoke Test. I was only able to access the Air intake after the MAF, the Intake after the intercooler into the Air Doser, the main crankcase vaccum pipe leading to the back of the engine and the EGR bypass pipe and the Air Doser pipe. The only signs of smoke came from the Air Doser pipe that leads up the top left side of the engine. Smoe was coming out of the Breather? 9black plastic box with a filter underneath)

I never expected to see any spoke from this point. I've attached a Vacuum hoe to both the EGR Bypass Valve and the Air Doser but can't seem to pull any readings from it. However i have seen both working when the engone is turned off. The EGR bypass opens and closes several times and the Air Doser closes to cut off the air.

3 months later and I'm as stumped as ever. I've not idea what to try next.


However, there is a very obvious (farting) Blowing, sucking air that i can't find. The exhaust smell is toxic, especially at startup and I still have a jerking at low revs or throttle position. Still no codes.

[atarilol]

Interestingly, on the DW10CTED4 engine fitted with this module, programming is required if fitted or replaced.....
.

How exactly do this programing? I have problem with egr in my engine. Is only reset learn values or I must do something after reset?

[GiveMeABreak]

This would be done via a professional level diagnostic tool, Diagbox in the case of PSA vehicles, but as you have a Ford Mondeo listed in your profile, that would not work in your case. You would need a diagnostic tool capable of this function for Ford vehicles.