ZD30 intermittent, cutting out under load / boost

[Lieney]

Engine is ZD30, manual GU IV wagon. 3" exhaust EGR blocked and dawes valve set at 17psi.
While driving engine hits about 3500 and shuts down. Releasing the accelerator and re-applying will make power return. No warning lights, just engine power loss for the time your foot is down.
Diagniosis by Hi-Tech diesel was pinched vacuum line at a cost to me of $90.
Still have problem now and is getting worse / more often.
Checked for 'this pinched vacuum line fault' today but couldn't find anything. Connections, plugs & hoses etc all appear good.
If foot is kept flat, engine cuts out between 2000-3500rps randomly. Occasionally plumes of white /grey smoke, but generally engine dies momentarily and then goes again. Almost as if fuel had air bubbles in it.
Boost is at 16-17psi set by dawes valve.
Any ideas as I am stumped

[threedogs]

White smoke not good, have you checked your fuel filter?
I'm thinking clogged or water in fuel, someone else may comfirm this
If possible disconnect the battery for an hour or so as well. Maybe a member in adelaide could check
and clean the MAF. Trying to remember a post recently where fuel wasn't holding pressure, but thats $$$$$
Try fuel filter, fuel lines, MAF and disconnect battery, that'll eliminate most

[mudski]

Engine is ZD30, manual GU IV wagon. 3" exhaust EGR blocked and dawes valve set at 17psi.
While driving engine hits about 3500 and shuts down. Releasing the accelerator and re-applying will make power return. No warning lights, just engine power loss for the time your foot is down.

Reduce the boost to max 15 psi.

Diagniosis by Hi-Tech diesel was pinched vacuum line at a cost to me of $90.

Easiest $90 he's made.

Still have problem now and is getting worse / more often.
Checked for 'this pinched vacuum line fault' today but couldn't find anything. Connections, plugs & hoses etc all appear good.
If foot is kept flat, engine cuts out between 2000-3500rps randomly. Occasionally plumes of white /grey smoke, but generally engine dies momentarily and then goes again. Almost as if fuel had air bubbles in it.
Boost is at 16-17psi set by dawes valve.
Any ideas as I am stumped

Shouldn't have done any damage I think. It's just limp mode kicking in thats why your getting no power and the you aren after you release and then press on the acc pedal...
I had the exact same problem with mine. But i could drive with 17psi if i accelerated hard and quick with full boost almost straight away. If I slowly accelereated and kept the boost up and really dragged out the gears I would hit limp mode. Turned it down a couple of PSI, felt no difference in power and stopped the issue.

[boots]

What mudski reckons ^^^ or dodgy throttle position sensor or common rails with full EGR block give grief / limp mode issues , you may have to look at getting a diesel smart module to prevent this issue or some guys reckon by drilling a small hole in the EGR blanking plate solves the limp mode issue .

[the evil twin]

What mudski reckons ^^^ or dodgy throttle position sensor or common rails with full EGR block give grief / limp mode issues , you may have to look at getting a diesel smart module to prevent this issue or some guys reckon by drilling a small hole in the EGR blanking plate solves the limp mode issue .

Tend to agree with you and Mudski 'cept shouldn't be the EGR. I haven't heard of that triggering limp and I've had mine blocked for about 30,000 now and all it does is throw a code every now and then (which it should). Quick check and reset with the Scangauge to turn the check engine light off and just to make sure it is P0401 is all that the CRD's need as P0401 isn't a limp code trigger.

I didn't see the point of drilling the blocking plate so I just bolted in one the Ferrets mostest awesomest products in and went for it.

[threedogs]

Just Checking if awesomest is a word, and too righty it is, X 2 on The Ferret products.
Now we know its a Di Z30 not a Cr
As for Mechanic, he was there we aren't think $90 for him to stop and check was
sorta ok. why is it everyone puts their hand out, GMF

[BearGUST]

What does the ECU cut when it goes into this limp mode? I always assumed it was boost but that can't be right if it still occurs when a Dawes valve is fitted. So it must change the fuel map, can someone confirm this???
I'm just trying to get an understanding to help diagnose the fault.

[threedogs]

May be the Info you need in one of Chazs {guru} threads in the search engine.
heaps written about this Topic. I thought just cut throttle.

[mudski]

What does the ECU cut when it goes into this limp mode? I always assumed it was boost but that can't be right if it still occurs when a Dawes valve is fitted. So it must change the fuel map, can someone confirm this???
I'm just trying to get an understanding to help diagnose the fault.

Just because there is a Dawes fitted does not mean there will be no limp mode. Well it does, but you have to have it set right. I don't know the exact number but I have found 16 is the limit, absolute, on my troll. I Could run anywhere up to 22psi but I had to drive it like I stole it to prevent it from going into limp mode. Reasons for that I don't know why. I set mine back to 15psi, found no difference is performance between 15 and 17psi so its no loss. Only I don't get limp mode now.
I would bet my left and last nut that if you reduce your boost the problem will disappear.

[threedogs]

X 2 Mudski, I was getting very frustrated with it, found that sweet spot and driving very well now, frisky if you like
Don't even think I get to 15 now but close to it