brianthemagical 1 Posted December 24, 2006 my dads 406 hdi 90, w reg is not starting, it's turning over but not catching. last night it worked fine. i've checked all i can but can't find anything, or the primer pump. any help would be greatly appreciated as my GTi is the only car that works and we need to visit family, thanks. Share this post Link to post Share on other sites
Guest BrainFluid Posted December 24, 2006 Have you took the fuel return pipe off to see if fuel is getting through when turned over? Is the fuel stop solenoid opening as it should and letting the diesel flow? Share this post Link to post Share on other sites
ablister 31 Posted December 24, 2006 Hard to tell but might be air in the system. Check all pipes and try priming the system before starting. Brainfluid, this is a HDI engine, not a XUD9 so doesn't have a fuel stop solenoid... Share this post Link to post Share on other sites
Guest BrainFluid Posted December 24, 2006 Really? How on earth does an HDI stop running then? Share this post Link to post Share on other sites
ablister 31 Posted December 24, 2006 the ecu tells it to stop Share this post Link to post Share on other sites
Guest BrainFluid Posted December 24, 2006 Yeah yeah but by what mechanism? Share this post Link to post Share on other sites
brianthemagical 1 Posted December 24, 2006 thanks for all the help. the fuel pump (in the tank) was cream crakered, anyone know of a motor factors open tommorow? thanks again and merry christmas. Share this post Link to post Share on other sites
ablister 31 Posted December 31, 2006 (edited) Yeah yeah but by what mechanism? I appologise, there is a fuel stop solenoid in the high pressure pump but i've never heard of it to fail, sorry. That'll teach me! Edited December 31, 2006 by ablister Share this post Link to post Share on other sites
welshpug 1,657 Posted December 31, 2006 thanks for all the help. the fuel pump (in the tank) was cream crakered, anyone know of a motor factors open tommorow? thanks again and merry christmas. pug only part as far as I know Share this post Link to post Share on other sites
brianthemagical 1 Posted January 9, 2007 another fuel pump has gone. it was from gsf and "for most hdi's", just not mine. i made it fit but after three days of use it's gone again. any ideas? there is 12v at the plug for the fuel pump, no more. i would have thought that all pumps run on 12v it being incorrect wouldn't have been a problem. i'm gutted. thanks for any help. Share this post Link to post Share on other sites
ablister 31 Posted January 9, 2007 if there's 12v reaching the pump then it'll more than likely be the pump. Have you tried switching the ignition on and checking for power at the pump? It should get 12v for 7 secs. You can also get someone to hold the fuel filter housing in engine bay and see if it vibrates while you switch igntion on, this should prove it's getting fuel pressure. The pump is controlled via a double relay (brown multiplug iirc) in the engine bay usually in o/s inner wing but can be found in n/s inner wing. Also worth considering. Share this post Link to post Share on other sites
brianthemagical 1 Posted January 10, 2007 thanks for the reply. the fuel pump is broked, i tried it on a known 12v, and the pump was getting 12v in the car. the ponit at the mo is it went after 3 days of replacing the previous one which was broken, at £70 each i don't want to risk just putting another one in so i was wondering if there is anything that would make it break so quickly, or is it juat bad luck? thanks again. Share this post Link to post Share on other sites
ablister 31 Posted January 11, 2007 sounds like a duff pump. I'd take it back as it should've lasted longer than that! Share this post Link to post Share on other sites
brianthemagical 1 Posted January 12, 2007 cheers. it's in the post at the mo. i was just wondeing if there was a fault with the car as the two pumps went within 3 days of each other? thanks again. Share this post Link to post Share on other sites
ablister 31 Posted January 13, 2007 probably just a fault with the replacement pump. It's not unusual for hdi's to get low pressure pumps so nothing to worry about. I replaced one this week too Share this post Link to post Share on other sites
Owain1602 0 Posted January 13, 2007 Shouldnt really "make things fit" when it comes to in tank fuel pumps. Common rail non start problems arent as easy as mechanical diesels to fix without diagnostic equipment unless its obvious. The diesel pressure is vital to the running of the engine as well as the temperature of the fuel. If rail pressure drops below 220bar whilst cranking, the engine wont start due to lack of lubrication. So pressure and temp sensors can cause problems. It stops the engine by not opening the injectors, there isnt a stop solenoid on the system, the only actuator on the high pressure pump is the 3rd piston deactivation which opens the valve to the return in the 3rd cylinder in the pump which doesnt allow pressure to build up in that cylinder therefore lowers the delivery pressure to the rail. The actual system is a bit like a petrol injection in that is switches the injectors through the ECU but they have a pilot injection to heat the chamber up prior to the main injecton and to keep the engine running quieter. I would check simple things first but if you cant find anything I would get a code read just incase you have other problems. Plus any contaminants in the fuel on this type of system is fatal due to such fine tolerances in the pump and injectors. Good luck, might be obvious, might not. Share this post Link to post Share on other sites
brianthemagical 1 Posted January 14, 2007 sound, thanks for the replys. the in tank pump was broken, i fitted a new one which made the car work then the car stopped and the pump was broken. i haven't touched the high pressure stuff as 1300 bar sounds scary. the 'making it fit' only consisted of changing a terminal, putting on a new piece of fuel hose and hoping the losse fit wouldn't be a problem. i see your point about the high pressure system not getting enough fuel but the tank is fairly full at the mo and the pump is well submerged, the is also a sort of swirl pot effect created by the fuel pump holder device which should prevent air being sucked up. thanks again. Share this post Link to post Share on other sites
Owain1602 0 Posted January 14, 2007 I wasnt on about the pump not picking up fuel really but more, is the high pressure pump building up enough pressure to allow the ECU to start the engine. I would get a code read really, get someone decent because crap info can could cost a lot of money. Share this post Link to post Share on other sites
brianthemagical 1 Posted January 14, 2007 thanks again, at the mo the lift pump is broken so when i get that back i'll get a code read. thanks. Share this post Link to post Share on other sites
davev 1 Posted January 15, 2007 does anyone know what the high pressure reading should be on the fuel pressure? its just my mates hdi is suddenly limiting his revs and cuts out regulary. an aa man said its a valve in the middle of the fuel rail. but i saw the pressure its was the car was running on and wondered if that would confirm it Share this post Link to post Share on other sites
brianthemagical 1 Posted January 17, 2007 between 200 and 1350bar. the kind of pressure duct tape can hold. look in the haynes manual. Share this post Link to post Share on other sites
davev 1 Posted January 18, 2007 cheers. the pressure was 395bar so i think it should be ok. he got a price for the thingy and the quoted £175 so he aint in a hurry to fix it as he has other cars to drive Share this post Link to post Share on other sites
