Blocking the EGR Valve

[the evil twin]

My updated after some more fiddling. I have the 2008 CRD with diesel gas fitted. I fitted a boost guage which noted normal levels up to 15max. I did the EGR block which saw occasional boost up to 17 but by and large the boost seems well controlled by the ECU as I was told to expect in a CRD.

I have just added a 2.5" mandrel exhaust and a pyro gauge and now I am seeing frequent over boost up to 19-20 under light load in 2nd or 3rd gear, on a slight incline. EGT 350-450.

Should I now just adjust the actuator a little? Will this level of boost be likely to do any harm to my engine?

cheers
Harry

An extra 5 PSI of boost pressure (20 instead of 15) multiplied by the ZD30 Compression ratio of 17.9:1 means you are now banging off at significantly higher chamber pressures of maybe mid 600's instead of around 550.

Up to you, cobber but I was pretty sharpish in winding my VNT down. I did, however see higher spikes on mine (22) than you have recorded so far.

[nallington]

hi guys im new to this forum already learning, i have GU 4.2 turbo and heard that a CRD valve would help with power but didnt have a clue where it was is it possible does the 4.2 have similar valve and can the same be done on 4.2 we tow a 23 foot caravan and a little more power would be appreciated

Thanx

Neiul

[the ferret]

Hi nallington, If you mean EGR, then your truck will have one if is a 4.2 TDI. ( Exhaust Gas Recirculator)
Welcome to the forum mate

[nallington]

thanx ferret will be out first thing in the morning looking for it much appreciated

Neil

[the ferret]

thanx ferret will be out first thing in the morning looking for it much appreciated

Neil

Looks like this.

[nallington]

Hi ferret regarding the EGR i have a 4.2turbo none intercooled there is a vacuum operated valve that looks like it operates a butterfly valve on the turbo but doubt if it is an EGR any further info would be appreciated

Neil

[nallington]

Thanks for that tony i will check to make sure its working as it seemed quite stiff this may be causing a loss of power.

Neil

[Gert B Frobe]

Just a question about the ECU's on the CRD engines.

If the ECU is so smart and limits the boost, why is it after fitting the shim does boost spike so much? I thought the whole idea of modern electonics was to make things simpler and more controlled......

My two cents

[Timbo]

Just a question about the ECU's on the CRD engines.

If the ECU is so smart and limits the boost, why is it after fitting the shim does boost spike so much? I thought the whole idea of modern electonics was to make things simpler and more controlled......

My two cents

Ok, in my opinion, the factory ECU isn't designed to figure out why 2+2 is equaling 5.
There may be codes in there that equal 4 for a particular type of part.

The EGR might have a sum like, 2+2=4 and this is based on a calculated amount of air running through a sensor around that part. The part is designed in such a way that it will always read as 4. So then we go and block it off. The ECU now doesn't get an air reading form the sensor. 5 may be a code for "add more boost", and 3 might be a code for "engine no start".
So all of a sudden, the sensor returns the number 5 back to the ECU.. 2+2=5.. shit, "add more boost".. nope, can't do that. 2+2=3. I'm not starting this engine because something is wrong.

Sometimes this is how I look at problems with engines.. in a real lay-mans way.

I would imagine it's because the ECU's are programmed from the factory to monitor standard parts. When you go altering things, the ECU doesn't know this and would just be making normal calculations. Sometimes when a calculation doesn't add up or a particular set of numbers appear to be outside of a certain range, the ECU may try and correct this by adding more/less fuel, more/less air and I guess, more/less boost. This may appear as a spike in an electronically controlled boost engine. Other time the engine may just refuse to start due to the ECu not being able to run it's programming etc.

Probably not a correct answer but hey, it's maybe its along the right track.

[CoR]

Hi guys,

I know it's recommended to fit a EGR gauge (or Pyro) when blocking the EGR valve, but has anyone actually had any problems by blocking the valve with or without a gauge?
I mean in general has or is there any overheating for normal use of the vehicle etc (not going extreme 4wding)?
Or are we talking problems with boost and overtemp?

Just looks like a prick of a job to fit with the standed exhaust.

Thanks,

CoR