92a Posted November 29, 2014 Share Posted November 29, 2014 Hi All, I am trying to get a 300 tdi to run after it broke a belt, it starts easily but pumps loads of smoke and revs much too high for tick over and backfires, really had enough of it and would like some advice please it has had a new lift pump and head gasket as we could not find a couple of lash caps and took the head off to locate them all , also new push rods and replacement rocker shaft, tappets have been set no egr any more either, Any ideas would be great Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted November 29, 2014 Share Posted November 29, 2014 Timing set correctly? Quote Link to comment Share on other sites More sharing options...
92a Posted November 29, 2014 Author Share Posted November 29, 2014 Supposed to be, have you had one that was out that ran poorly? we bought an engine that had broken its belt as it must have been running to break the belt, the original ran but would not rev which we thought had the head gasket gone? Quote Link to comment Share on other sites More sharing options...
Tanuki Posted November 29, 2014 Share Posted November 29, 2014 The last one of these I dealt with had a fistful of banana-pushrods. The owner said "So, replace them". I refused to do so without lifting the head and seeing what other mayhem had happened. In this case I was 100% justified - there were messily-serious 'witness-marks' on all four pistons. Further questioning revealed that the owner had been doing 70+ MPH when the belt let-go. At that sort of speed the cam doesn't stop-dead when the belt strips; rather, rotational inertia means it goes-on for another half-rev-or-so and when it stops it leaves valves in inconvenient levels of open/closedness. Quote Link to comment Share on other sites More sharing options...
92a Posted November 29, 2014 Author Share Posted November 29, 2014 We found 3 broken rockers and almost all push rods bent, but these have been changed, if it was going fast enough to smash all those bits then hoped every thing else was good before it let go , ie pump injectors etc I have attached a couple of pictures I took earlier, how do I know the crank is not 1 rotation out? Quote Link to comment Share on other sites More sharing options...
western Posted November 29, 2014 Share Posted November 29, 2014 the attached page, right hand column might help with setting/checking timing, Quote Link to comment Share on other sites More sharing options...
Tanuki Posted November 29, 2014 Share Posted November 29, 2014 Given the smashed-rockers evidence [which means things must have got pretty bad inside] I'd insist on lifting the head and seeing what sort of piston-damage witness marks exist before proceeding any further. Quote Link to comment Share on other sites More sharing options...
Green Bob Posted November 29, 2014 Share Posted November 29, 2014 how do I know the crank is not 1 rotation out? It can't be, the pistons are either up or down (or moving up or moving down)... Quote Link to comment Share on other sites More sharing options...
92a Posted November 29, 2014 Author Share Posted November 29, 2014 Thanks for that Bob, seems so simple when someone explains it like that, will try another injection pump in case that is causing the problem, we had the head off and put a new gasket on when we were looking for the lash caps and I had a good look at the timing (before posting up here) and it looks alright, cant believe that two engines have almost the same problem, hence the new lift pump as it was the only thing we swapped over from the original engine any other ideas would be great? Quote Link to comment Share on other sites More sharing options...
smallfry Posted November 30, 2014 Share Posted November 30, 2014 Ah. So you bought and engine that was already blown, and have never actually had it running properly then ? It might have been running away with itself which caused it to overrev and blow in the first place. If it has over revved due to breather or turbo oil getting into the intake air, it may have reduced the piston rings to cheese, or scuffed the piston ring lands, allowing blowby (low compression) As the pistons and valves have collided, it might have cracked or holed pistons, or possibly a cracked head. 300tdi heads are a bit fragile anyways. If you are sure the timing is correct, I guess a compression test would be a good next step ? On the other hand, the injection pump may have been "modified" by one of these people who know "all about diesel tuning". In which case, good luck with that ! Quote Link to comment Share on other sites More sharing options...
Jode Posted November 30, 2014 Share Posted November 30, 2014 If the engine is "running away" at idle then the idle is incorrectly set. The lr workshop manual for the 300 TDI shows how to set the idle - if I were you I'd do that first in order to eliminate THAT issue. If it smokes regardless of engine rpm and the smoke is grey-black the timing is probably badly retarded. If however it smokes only under acceleration then the fuel screw on the injection may have been fiddled with, resulting in increased fuel delivery. If it looks like retarded timing, you should checke the pump lift at TDC - if this is not set correctly you can align all of the timing marks behind the timing cover and you'll STILL be running off-timing. Quote Link to comment Share on other sites More sharing options...
92a Posted November 30, 2014 Author Share Posted November 30, 2014 Thanks for the ideas put a new(2nd hand) pump on and new (2nd hand ) injectors and it was a bit better, but noticed the top hose from intercooler to inlet manifold was collapsing when it tried to rev so decided to try it as a N/A and found one of the hoses on the way to the intercooler had delaminated and was blocking air flow much better now this hose has been replaced Quote Link to comment Share on other sites More sharing options...
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