Roverdrive Posted May 24, 2016 Share Posted May 24, 2016 Hi all, After a couple of pointers, rather than he complete " how to adjust your pump" from the archive. I have no idea if the pump was adjusted by the previous owners, so cannot be sure of the base line. It is a 97 300tdi in a 110 station wagon. It looks as though it may have had an EGR at some point as there is a flat plate on the exhaust manifold. There is also an electric a plug on the Fip that is not connected, and there is no harness to it. If I accelerate gently there is no smoke. If I apply more than (say) 75 % throttle, there is black smoke. If the throttle is held steady, this smoke gradually diminishes as the vehicle speed / revs rise. The vehicle has always felt fairly spritely, though other people say it is normal ! A new turbo was fitted last year, but the issue has been there since I bought the vehicle. Can anyone suggest the first thing to adjust to reduce the smoke? Fuel consumption with brownchurch rack is about 26mpg, and vehicle will pull well up to *ahem* 70 mph. Cheers for any pointers. Mike Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted May 24, 2016 Share Posted May 24, 2016 Change air filter, change fuel filter and check all the air intake and intercooler/turbo pipework is ok. Flush the intercooler if you feel up to it. Then see if there's any improvement. Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted May 24, 2016 Share Posted May 24, 2016 But PS - a bit of black smoke under load is normal. but if its like a scene from Apocalypse Now and is a black coil curling behind you there's a serious problem! Quote Link to comment Share on other sites More sharing options...
Roverdrive Posted May 24, 2016 Author Share Posted May 24, 2016 Should have added that the air filter had been changed previously. I just think there is more smoke than there should be. My 200tdi Disco was clean burning in comparison. Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted May 24, 2016 Share Posted May 24, 2016 I had my fuel pump overhauled recently (and reset to 'standard') although it had previously been 'tweaked' a little as part of an overhaul by a well-respected engine builder/tuner, as part of which overhaul the turbo was replaced with a hybrid unit. After the recent pump overhaul it smoked very badly and was down on power. Long story short - after tracking down the low-power problem to an unusual internal pump failure despite it being overhauled, power was restored but it smoked too much. I was advised by the engine overhauler to increase the turbo boost a tad which I've slowly been doing and its decreased the mid range smokiness considerably but is still operating within the recommended boost range of the turbo (I fitted a boost and EGT gauge to be safe). It might be that a simple turbo boost tweak will remedy it. If you dont have the boost gauge, fitting one is easy, and you can easily fit an EGT gauge too on a 300 if you remove the flat plat on the manifold and drill and tap it and fit the probe there. I will add though that I'm no expert - I'm learning as I go! And there may be other real experts who'll chip in with their advice! Quote Link to comment Share on other sites More sharing options...
Roverdrive Posted May 24, 2016 Author Share Posted May 24, 2016 EGT gauge is on the "to do" list when I have some spare cash. I am not happy to tweak the pump upwards until I can monitor the temps, especially given a sudden turbo failure last year, though that was bearings not blades. Will look at a boost gauge to see what it is actually doing, and clean out the intercooler in the mean time. Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted May 24, 2016 Share Posted May 24, 2016 I dont think you need to tweak the pump - black smoke is over-fueling (unburnt fuel) so no need to increase fuel delivery I'd suggest, though increasing turbo boost a tad might help increase air/fuel mix and give a better (cleaner) burn. I fitted the EGT and watched what was happening when the pump was misbehaving and coincident with chucking black smoke out the back the EG temps were very high. Now that the pump is fixed*, at the same engine revs and speed the EG temps are 100 degrees lower and much less smoke out the back. * The pump problem I eventually discovered was that the boost pin in the pump was jammed during the cyclic bench test when being overhauled by the Bosch agent, so after overhaul the fueling didn't alter according to engine load and turbo boost. The result was it was running lean and down on power in some areas and way rich in others with the unburnt fuel getting dumped out the back. Surprisingly it was the first time the pump engineers had seen such a jammed pin problem in 30 years of working on Bosch pumps. Strangely enough they had another come in three weeks later - same problem - and they suspect (with no hard evidence though) that it might be down to lubricant deficiencies in modern low-sulphur diesel. Check all your piping to make sure there's no holes and that all the jubilee clips are intact too. Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted May 24, 2016 Share Posted May 24, 2016 Just a thought - you might want to check the boost pin is operating properly. I discovered mine was jammed - and did it easily enough - take 4 screws out of top of pump, lift off top, and the black rubber diaphragm attached to the boost pin should be 'springy' and able to be pushed down against the spring pressure, and easily lifted out (may need a slight turn to 'ping' in the fuel pin that butts against the boost pin). If it doesn't move (mine didn't) then the boost pin is jammed and as a consequence the diaphragm will not move relative to the turbo operational demands, and the fuel delivery will not be altered accordingly. That can lead to over-fueling and black smoke at certain speeds/revs - so its an easy thing to check and discount from the possible causes. Quote Link to comment Share on other sites More sharing options...
Roverdrive Posted May 25, 2016 Author Share Posted May 25, 2016 Just had a look at the fuel pump, and the boost pin is free to move, however I noted that the cheese head screws were damaged, and the anti tamper plug missing. When examining the taper of the central gizmo, there are two distinct wear marks, so it looks as if it has been turned clockwise by 90 degrees. Mike Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted May 25, 2016 Share Posted May 25, 2016 Hmm - someone has been in about it then. Might want to try returning it to the original witness mark and see what happens. Maybe in between both is the sweet spot! Quote Link to comment Share on other sites More sharing options...
Roverdrive Posted May 25, 2016 Author Share Posted May 25, 2016 Well I had a look in the technical archive and made an adjustment to the diaphragm stop screw. I have taken it back in steps about one full term. The smoke seems to be less and while there is some visible it is certainly not as antisocial as it was before! I did a quick boy racer acceleration run and got about 16 seconds to 60 over two directions. Not bad for a 17 year old 110 with a roof rack. Now to find an ETG Quote Link to comment Share on other sites More sharing options...
Leaky40 Posted May 29, 2016 Share Posted May 29, 2016 Sounds like your going in the right direction. I adjusted mine after buying and fitting a egt and it certainly gives you comfort knowing your not about to melt your engine internals? I got a cheap one of eBay from China I think. It was about £18 and took about a week to come and has been working great since. I did however have trouble with which wires go where but the seller was extremely helpfull? It came with all the wires and I just needed to drill out my egr blanking plate and weld the probe in? It's been in use for 2 years and done approximately 15,000 miles. Mine is now set to hold 60mph uphill with minimal smoke (for a Landy? ) It's a 300tdi 90 on 184,000 miles. Quote Link to comment Share on other sites More sharing options...
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