Hi guys, Our Jetta 16v is mucking about. It starts but dies almost instantly, if you try and give it some gas this does nothing. We bought a brand new bosch pump and fitted and tried a working pump relay (from my mk2 16v). It has also had a new OEM distributor because the seal was leaking. Only thing we haven't changed is fuel filter but I have one sitting in the cupboard. Could it be the lift pump in tank? This is because the main pump seems quite loud. Anyway, hopefully the video is helpful: http://s206.photobucket.com/albums/bb55/Alexandthegolf/?action=view¤t=IMG_1660.mp4 [/URL][/IMG] Thanks in advance Alex
should have mentioned that, half a tank of super. I thought it may have been because the new pump needed to draw fuel through, but after at least 5 or 6 attempts it was still doing the above.
check the rubber hose from metering unit to inlet manifold is fitted properly and has no splits in between the bellows and that the run on valve is plugged in underneath as it sounds just like a chronic air leak.
Right I think the lift pump is dead as I tried what you said and no click. Is it possible that the lift pump dying would have caused the old main pump to overload too? Checked for connections on airbox and to inlet manifold, all fine
Seems unlikely to be a lift pump as, in my experience, the car will still run and drive without it but suffer surge under heavy load. Also the fact that it starts up on the 5th injector (cold start) suggests there is pressure. First thing would b 2 turn the engine over so that it fires and cuts out and then 2 crack the fuel supply union to the metering head to see if u have pressure - mind your eyes! this will rule out the fuel pump.
yep without the lift pump the main pump will strain to suck fuel out of the tank, and eventually die. its happened on here time and time again. yeah in the short term it'll work, but in the long term you need to replace the main pump. it can also lead to the reservoir running dry in cornering/low fuel conditions which kills the pump quickly as the fuel also acts as lubrication for the pump internals. also, if you changed the main pump the reservoir will be empty, and the main pump will really struggle to get any fuel at all without the lift pump to fill up the reservoir! so get the pump changed asap.
RJ, Dad said when he changed the main pump there was loads of fuel in it. If the lift pump was dead it wouldn't be supplying the main pump though would it? Hope that makes sense?
yeah the main pump tank should be full of fuel, even with a dead lift pump the main pump can just about manage to get fuel from the tank though it wont like it. as you say, once you put a new one on there though it has no fuel in the reservoir and the main pump has no chance of sucking any up from the tank. it needs to be fully submerged before it can pump anything! you need the lift pump to get the reservoir filled with fuel, then it should go. or if not, you have at least solved one of the problems best to check the pump by giving it 12v direct, maybe its the wiring or pins rather than the pump? the lifter is under a metal disc under the boot carpet, the red/yel wire is the 12v feed to it and the brown is the earth. though if its the original lifter pump its done aright really just some notes, new lift pumps usually come on their own without the level sender unit, so you'll have to swap it over. if you go for a complete unit 2nd hand, make sure its a pre-90 with 3 pins as 90spec have 4 pins and a different plug. though you can still fit the 90spec unit if you splice on the 90spec plug, or you can swap the pump over. oh, and make sure the new pump comes with the mesh filter, as there are 2 sizes. asnd you know sods law if you buy one without the old filter wont fit it
thanks a lot RJ, some super advice there. Nothings easy is it Will get Dad to run 12v through it and then go from there. Cheers
