blowmeover Posted January 10, 2020 Share Posted January 10, 2020 Getting air in the leak off, coming up from the pump to the injectors leak off, causing white smoke and missing on start up, clears after about 5 minutes, when the engine is shut off I can hear the return drain down into the tank, with the engine shut off if I open the throttle I can see air rising into the leak off (clear pipe from pump to injectors). No sign of leaking, engine performs as normal, new filter fitted. Any ideas? This is a replacement engine, It didn't have a lift pump so I fitted the pump of my old 19J, its a sealed Delphi unit and worked before the engine transplant so although it still could be the problem Its unlikely, especially as it worked fine before and the engine runs as normal. Fuel pipes could be the issue but no leaks, I will check them today, they probably are due replacing anyway, injectors seem OK but cant vouch for them, I have a spare set so can always swap them out if I have to, The thing is, if the system is draining down to allow air in , where is the diesel going? If air is getting in the diesel has to be going somewhere? Quote Link to comment Share on other sites More sharing options...
monkie Posted January 10, 2020 Share Posted January 10, 2020 For air to get in, it doesn't necessarily mean diesel will be leaking out. It sounds very much like it is getting in at the spill rail and the diesel will just return to the tank as the air gets in. I would first check all of the unions on the spill rails in terms of washers and no loose connections. It is also possible for a split in the boost diaphragm to cause this. Have you checked the boost diaphragm or do you hear a hiss of pressure escaping from the fuel tank when you stop to fill up? Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 10, 2020 Author Share Posted January 10, 2020 From past experiences when the boost diaphragm splits diesel leaks out of the housing, I will check by pressurizing the pipe to the turbo, see if its letting past, there is no diesel in the pipe from the boost diaphragm to the turbo. I dont think its the spill rails, its air in the pump passing up into the spill rail, I can see the bubbles coming up from the pump, I have a clear pipe from the pump to the spill rail. Quote Link to comment Share on other sites More sharing options...
monkie Posted January 10, 2020 Share Posted January 10, 2020 The split diaphragm doesn't necessarily result in leaking diesel, it just allows direct access for the air from the turbo to get past the diaphragm and into the fuel pump. The spill rail is a poor design on pre-tdi engines as it feeds into the filter head and back to the pump so the air can go from the spill rail, to the filter and up from the pump again making it tricky find the leak and to bleed the air from the system. Check all unions in a methodical way, starting with the injectors back to the filter and pump. Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 10, 2020 Author Share Posted January 10, 2020 So here is what I have found, boost diaphragm pipe off at turbo end, if I put a vacuum on it, it holds steady. If I put positive pressure into it, it just allows air through and I can see the spill rail filling up with air. So I tried the same on my old engine, it holds a vacuum and when positive pressure is applied it will allow some air through then it will gradually stop. So, something is wrong down there, if the boost diaphragm were split surely it wouldn't hold a vacuum? Its a long time since I changed one so Im struggling to recall how they worked. Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 10, 2020 Author Share Posted January 10, 2020 I see now how it works, I pulled the old one off the old engine and the one off the current engine, the current one is indeed split, the one from the old engine however is different, could be none genuine, anyhow, some careful measuring I reckon to get the pin right? Or do I go flush like it was on the split one? The split one is on the right. Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 10, 2020 Author Share Posted January 10, 2020 (edited) Done, The difference was one has a shim and the other doesnt! no more air coming through though, I didn't bother measuring the pin, what I did was disassemble the whole thing and switch the diaphragms, this meant the pin stayed intact in the body and didn't need to be adjusted. Contrary to popular belief that 10mm nut does not seem to tighten the pin up, it doesnt have to be loosened to adjust the pin, but if you strip it all down taking care to keep it all in the right order you can just replace the rubber section without touching the pin. A quick drive and it smoked like hell, it mostly cleared after a while but its still there although not as bad, no air in the spill rail when I shut it off except for the odd little bubble, I guess it will be a few more miles before the air clears completely but so far so good, Im letting it cool now to see what cold starting is like. Its going really well, surprisingly well for a 19J. Thanks for the help Monkie, greatly appreciated. Edited January 10, 2020 by blowmeover Quote Link to comment Share on other sites More sharing options...
monkie Posted January 10, 2020 Share Posted January 10, 2020 Glad you got it sorted out. 1 Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 11, 2020 Author Share Posted January 11, 2020 Still not right, starting from cold, no throttle, it will try and start, give it a little throttle to help it along and it dies. Its a bit of a hit and miss start. Glow plugs are spot on, could the cold advance be the culprit? low fuel pressure at cranking speed? Quote Link to comment Share on other sites More sharing options...
monkie Posted January 11, 2020 Share Posted January 11, 2020 Timing. I suspect it may be a little retarded. Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 11, 2020 Author Share Posted January 11, 2020 11 minutes ago, monkie said: Timing. I suspect it may be a little retarded. I might give the pump a little twist and see if that helps, the engine has been knocked around, lying on its side on a pallet, lifted by a fork truck, bashed around putting it into the Landy (engine crane on a gravel drive) so it might have taken a knock on the pump. From memory, advanced results in white smoke, retarded black? Or have I got that the wrong way round? Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 11, 2020 Author Share Posted January 11, 2020 I have not checked the timing yet, had to go out so took it for a drive, loads of white smoke for the first few miles then it cleared, if the timing was out would it not smoke even when warm? Quote Link to comment Share on other sites More sharing options...
steve b Posted January 11, 2020 Share Posted January 11, 2020 Check your fuel line connections from the tank to the FIP , it sounds like an air leak . Any non-standard fuel lines/connections would be particularly suspect . Is the fuel filter clean ? If all of that checks out ok then the next suspect would be fuel lift pump . cheers Steve b Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 11, 2020 Author Share Posted January 11, 2020 I had a play with the pump, looking at it from the front of the engine I turned it anti clockwise about 2 mm, took it for a drive, no white smoke (although the engine was warm anyway) but lots of Black on take up, even at idle lots of Black smoke when revved. So I took it back to where it was , I might try again when its cold. From memory if you go too far one way or the other its either white or black smoke? All the lines are good, filter is new, could be the lift pump although it worked fine in the old engine. Quote Link to comment Share on other sites More sharing options...
steve b Posted January 11, 2020 Share Posted January 11, 2020 Black smoke is too advanced in this situation , probably along with a more pronounced diesel knock Steve b Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 11, 2020 Author Share Posted January 11, 2020 This is it starting from warm, its worse when its cold, Im wondering if Ive got a bad injector? https://www.youtube.com/watch?v=3nARec8XCFg&t=56s Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 11, 2020 Author Share Posted January 11, 2020 https://www.youtube.com/watch?v=3nARec8XCFg&t=56s Sorry, dont know how to embed a you tube video. Ive just set up the tappets and it didn't change anything. I do think this engine was laid up for a while so it could just need a really good run? Quote Link to comment Share on other sites More sharing options...
western Posted January 11, 2020 Share Posted January 11, 2020 Put some injector cleaner/lubricant in the tank & go for a decent long drive to get everything to full working temperature. Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 11, 2020 Author Share Posted January 11, 2020 I might try that, from putting the engine in its probably done about 60 miles, but on a split boost diaphragm, I could pull the old injectors out of the old engine and put them in, Im sure I have a new set of washers somewhere. Quote Link to comment Share on other sites More sharing options...
monkie Posted January 11, 2020 Share Posted January 11, 2020 White diesely smoke is the injection too far retarded. Black smoke and a bit of knock is injection too far advanced. A set of recon injectors goes a long way with these engines to help keep them running well. Quote Link to comment Share on other sites More sharing options...
steve b Posted January 11, 2020 Share Posted January 11, 2020 If you decide to go for serviced/re-con injectors I use M&C in Colchester , they will collect and return when sorted and they know what they are doing and well priced the last time I had cause to call . cheers Steve b Quote Link to comment Share on other sites More sharing options...
monkie Posted January 11, 2020 Share Posted January 11, 2020 1 hour ago, steve b said: If you decide to go for serviced/re-con injectors I use M&C in Colchester , they will collect and return when sorted and they know what they are doing and well priced the last time I had cause to call . cheers Steve b Do they do so by post? There seems to be a shortage of good diesel specialists near me who will do this for a reasonable price. Do they also recondition injection pumps? Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 12, 2020 Author Share Posted January 12, 2020 I was just going to swap the injectors over from the old engine for now, the old one ran fine but had a loud tapping noise before boiling over, suspected crack in the block or head. It will be prudent to get these ones reconned though, and the spare set I have in the shed. Quote Link to comment Share on other sites More sharing options...
monkie Posted January 12, 2020 Share Posted January 12, 2020 I would get a set sorted out with new nozzles and calibrated as a priority. It may do little for your smoke problem but these engines do not tolerate poor injector spray and a lapse in service regime. Poor spray causes irratic combustion and is one of the causes of cracks in pistons and the head. I had a melted piston in a 19J I bought to rebuild and the injector looked to be in awful condition. Quote Link to comment Share on other sites More sharing options...
blowmeover Posted January 12, 2020 Author Share Posted January 12, 2020 I took the nozzles apart on my spare set last night, a couple were tight but freed up after twisting the pin a little and extracting them from the nozzles. I have no way to set the opening pressure as I need a pop tester for that but at least They can be made good without having to replace the nozzles. I will ask around today and see if anyone I know has a pop tester. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.