300tdi doughy when cold

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Originally Posted by jskerm

Re-check the timing. I had a defender that was gutless when cold and blew a lot of white smoke, mainly when first started and when engine was coming down from high idle, ie coasting. I did the timing belt and found the engine to be retarded quite a bit. White smoke is unburnt fuel, as long as it's not steam. I have since, whilst tinkering, advanced a 300 tdi too much and found it did the same, went like stink when it was warm but couldn't handle the advance when it was cold. I am not 100% but im pretty sure that these engines have an automatic advance on cold start up. Ie the engine advances itself slightly until warm. If your timing is set up to be advanced, the autoadvance can move it to far forward, making it smoke.
So anyway, that's where i'd start, check the timing.....

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Timing is 100% spot on. I set it up as per the book, and rotated the engine several times and rechecked. Even used a phone camera to take a pic of the cam marks from the right spot - since you can't look straight at them with the AC rad and grille still in place.

Some more info. When you start it without glowing, it still starts quite well, and doesn't blow white smoke until about 10 seconds later. When you try and rev it while stationary it will rev till 1500 rpm, and then sit there for 3 seconds or so before reving higher. As I said it needs to be driven for at least 100m until it has warmed up enough. It then drives normally and doesn't blow any smoke at all under any conditions.

Check your fuel filter isn't sucking air, i gather it was changed when the head was done. Check that no fuel lines were damaged and check your transfer pump. If you are confident that side of it is all good and the timing is spot on (ie hole in fuel pump is in line with groove in flywheel. 3/8 bolt in fuel pump gear) then i would think about pulling off the exhaust manifold, capping the turbo oil feed and starting the engine to see if the problem is isolated to one cylinder or all 4. If isolated to one cylinder try swapping injectors to see if the problem follows the injector. You may have bumped a tip causing the injector to dribble when sitting, filling the pot with diesel. Another option if you have a heat gun is to test the heat of the ex manifold at each pot to see if one is considerably cooler, indicating unburnt fuel coming from that pot. Thats my two bob anyway, sorry if im telling you how to suck eggs.

how'd you go?

Haven't had a chance to sort it yet, however lots of good suggestions to try...