hengti 2 Posted January 14, 2007 Hello all I'm GTi-less at the moment; it won't start. It's producing a spark, but the plugs are dry. I've been reading search all afternoon, but haven't spotted reference to the question I've ended up with. Probably 'can't see the wood for the trees'! The tachymetric relay seems ok - I've had the cover off and have cleaned up what looked like some sort of resin deposits at the base of the pcb and it does actually appear to be doing something (I've had a look at it with the cover off as I've been cranking the engine). Now suspect the fuel pump - I'm getting a relay click from the dash area at each stage of turning the ignition switch, but I'm getting no noise from the fuel pump. I've just had a look in the GSF/ECP catalogues - fuel pumps are £90! I'm wondering if there is any way I can check the output/input for the two leads that go into before I condemn the pump. One's white and the other's green. Can anyone suggest what I should be checking for before biting the bullet and going for another pump? Any help would be really appreciated. Thanks Henry Share this post Link to post Share on other sites
Guest cknotty Posted January 14, 2007 Can you check for voltage at the multiplug which connects to the fuel pump? Not sure if there is one on a GTI (haven't owned one yet!) If there's voltage getting to the fuel pump then the tachymetric relay must be fine? Try removing the fuel pump, dry it off and connect it directly to a 12V source as well: least you'll be able to know if the fuel pump itself is fine or not. Make the final connection to the 12V source (situated away from the pump) as sparks and fuel aren't a good combination outside of a combustion chamber! Share this post Link to post Share on other sites
steve@cornwall 100 Posted January 14, 2007 Hello all I'm GTi-less at the moment; it won't start. It's producing a spark, but the plugs are dry. I've been reading search all afternoon, but haven't spotted reference to the question I've ended up with. Probably 'can't see the wood for the trees'! The tachymetric relay seems ok - I've had the cover off and have cleaned up what looked like some sort of resin deposits at the base of the pcb and it does actually appear to be doing something (I've had a look at it with the cover off as I've been cranking the engine). Now suspect the fuel pump - I'm getting a relay click from the dash area at each stage of turning the ignition switch, but I'm getting no noise from the fuel pump. I've just had a look in the GSF/ECP catalogues - fuel pumps are £90! I'm wondering if there is any way I can check the output/input for the two leads that go into before I condemn the pump. One's white and the other's green. Can anyone suggest what I should be checking for before biting the bullet and going for another pump? Any help would be really appreciated. Thanks Henry carefully undo the 17mm fuel pipe union from the fuel rail, beware, it may have pressurised fuel in t, place the end of the pipe into a container and crank it over- see if the pump is actually at fault, or if it's an injector-opening problem Share this post Link to post Share on other sites
boombang 2 Posted January 14, 2007 Could even be ignition switch related. I got no power to the pump and it was just a broken wire to the 3rd position of the igniton. Share this post Link to post Share on other sites
hengti 2 Posted January 14, 2007 cheers for the suggestions guys. i've actually just spotted on search ( ) that the white wire is +ve and the green is -ve have also read somewhere that the pump switches on through the ign switch before the engine cranks, so i'm going to muck about with lengths of wire from the battery and a bulb to see what's what. if i'm not on again, i'll have blown myself up (cknotty!) Share this post Link to post Share on other sites
hengti 2 Posted January 14, 2007 (edited) still none the wiser after trying above can't get the pump to do anything by connecting it directly to the battery and the lightbulb connected to the wires that go to the pump (ign switch at third stop) test hasn't worked either (don't have access to a multimeter at the moment) a couple of things have occurred to me: - the fuel pump is under the bigger of the two grommets isn't it?! what's that under the smaller grommet? that's got an electrical socket plugged into it too - am i right in believing that there should be a current sent to the pump with the ign switch to the third posn? if the tachy relay is actually duff, would that stop the signal? thanks again ed. yep - cheers for below; should've twigged before i asked Edited January 14, 2007 by hengti Share this post Link to post Share on other sites
Guest cknotty Posted January 14, 2007 The other item under the rear seats is the fuel level sender. Share this post Link to post Share on other sites
sonofsam 5 Posted January 14, 2007 Have you tryed jabbing the pump (with it plugged in) with a live feed from say the cigarette lighter wich is permanenlty on. Share this post Link to post Share on other sites
hengti 2 Posted January 14, 2007 Have you tryed jabbing the pump (with it plugged in) with a live feed from say the cigarette lighter wich is permanenlty on. not sure i'm with you there Sam - are you suggesting leaving the two connections on and then 'adding' a second 12v input to the pos terminal somehow? i've tried disconnecting the wires from the pump and then running wires directly from the battery. the car's stuck at my place though, so i've not got access to the facilities and tools that i'd usually use at my dad's place - i'm not convinced that i've managed a decent connection at the fuel pump, so i'll rig something more substantial up at some point. i guess i'll be looking for another pump if that still doesn't work. not sure why i'm not getting anything through from the inputs though - again, have to rig something more substantial up to be sure i'm not. would still value suggestions as to what might be the problem here though. fhooked off with it now; too dark to continue play Share this post Link to post Share on other sites
sonofsam 5 Posted January 14, 2007 (edited) Sorry , didnt explain that very well, but you got it: are you suggesting leaving the two connections on and then 'adding' a second 12v input to the pos terminal somehow Thats how I tested mine, take a live wire feed from the plug in the back of the cigarrete lighter down to the back of the plug that goes into the plug on your fuel pump. feel your pain mate, as had this and tested and changed lots of parts, except the pump. Edited January 14, 2007 by sonofsam Share this post Link to post Share on other sites
hengti 2 Posted January 14, 2007 Sorry , didnt explain that very well, but you got it:Thats how I tested mine, take a live wire feed from the plug in the back of the cigarrete lighter down to the back of the plug that goes into the plug on your fuel pump. feel your pain mate, as had this and tested and changed lots of parts, except the pump. got it cheers i'll add that to the list; will also check the pump earth connection - have just thought that that might be the problem with the leads. off a-searching i go! Share this post Link to post Share on other sites
Ahl 4 Posted January 14, 2007 If I were you, I'd bridge the terminals on the tachymetric relay socket just to make abolutely sure it isn't that before shelling out for a fuel pump etc. You can find the wire numbers to bridge with a search. Share this post Link to post Share on other sites
hengti 2 Posted January 16, 2007 i'm sure it's the fuel pump now - 12v directly onto it produces nothing (i've taken it out now). the lightbulb test works as the engine is turned against the starter though - so i'm confident the tachy relay is ok just need to source a s/h pump now thanks for all of the replies Share this post Link to post Share on other sites
