D40 diesel stumble at 1000-1500 rpm

[Sean H]

Hi all, I have a D40 which breaks down/misfires between 1000-1500 rpm. After that it revs smooth and strong. The car has been sitting for a while after engine swap (used). Has new timing chains, fresh fuel, new fuel and air filter. I have cracked the fuel lines to bleed any air out of the lines. Interested to hear from anyone who has experienced this problem and found the cause.

 

[Old.Tony]

It would be interesting to see if this still occurred with the EGR blocked. If so, your EGR valve may be momentarily letting too much exhaust gas in causing the engine to choke until the valve settles into position better. If not, this is the RPM area where the D40 turbo starts spooling up, perhaps there's some old oil lying in the intercooler and it just needs a clean? Petrol does the trick, just sit it in the sun while you consume 2 beers (no less, and no more) before reinstallation.

 

[Sean H]

Thanks Tony, Responded a couple of times but I can't see it. For the moment I think it's o.k. Connected vacuum direct to the turbo actuator and took it for a run. Spools up o.k. Reinstated the plumbing and it seems much smoother now. Low idle lumpiness has gone away and now has steady idle. maybe re-learned?? Only an ABS,check engine and handbrake light to eradicate now.