Bast 10 Posted March 17, 2014 Hey all Car cut out a few weeks back at my mates garage after running for 10 minutes or so and refused to restart. Finally got round to checking it this weekend, I checked ECU and fuel pump relay, fuses, ECU plug and plug at the back of the ignition switch (has just been replaced). But for some reason, the fuel pump isn't priming on ignition....but, the car will actually start up (although it does seem to be suffering from a misfire) Am I right thinking the pump should prime? I also tried a different pump (albeit out of the fuel tank) and that still didn't do anything... Any ideas anyone? Quote Share this post Link to post Share on other sites
jimbobbalooba 0 Posted March 27, 2014 Sounds like connection problems. Stick a multimeter on it, you already have a fair idea that its not the pump so work your way back up the switched live and see if you're getting any current. That's the firs thing I would do after the stuff you've already done. Quote Share this post Link to post Share on other sites
robrado974 1 Posted March 27, 2014 Can you here the relay click ? Also if you can't here it prime replace the relay Rob Quote Share this post Link to post Share on other sites
Bast 10 Posted July 4, 2014 (edited) Slowest follow up reply ever. Thanks for the replies guys, not had a lot of time to have a look at the issue over the past few months. Car still starts (eventually) and runs (without the misfire now I should add) Just bridged the 2 main connections where the fuel pump relay should be and the pump ran fine. When the relay itself is actually in place the pump makes a short sharp noise but doesn't run,(tested this with a second pump as well) so guess it could be a duff (even though its new) relay or as jim mentioned a connection problem. Will carry on searching when I get hold of a multimeter, hoping that whatever is causing this is also the reason for it cutting out round corners when its a bit low (1/4 of a tank) on fuel. Edited July 4, 2014 by Bast Quote Share this post Link to post Share on other sites
Bast 10 Posted July 4, 2014 Just to add to this, just tried another relay out of another car to no avail. So guess its something to do with the circuit on ignition since the pump ran fine when I bridged conections 4 & 6 on the fuel pump relay socket. Any ideas are really welcomed on this one as I hate/am useless at electronics :D Quote Share this post Link to post Share on other sites
MarkB 10 Posted July 4, 2014 Is it a16v? If so, I had the same problem with a mk2, sounds like you've lost the ignition feed to the relay which keeps it live (and pump running) whilst you're cranking the car over. My fault ended up being a poor connection on the back of the fuse box, but you'll need to trace the wire back from the relay and go from there. The relay will have 2x feeds to it, 1x to power the relay switch side and 1x to power the fuel pump. Make sure you have both of these whilst cranking the car over (with relay in) or it could be an earth fault on the relay (generally a black wire) again make sure you got this while cranking the car over. Hope this helps?! Good luck Quote Share this post Link to post Share on other sites
Bast 10 Posted July 4, 2014 Cheers for that, another avenue to explore. Think I'm gonna have to get in behind the fuse box and have a good look. It's a VR6 bud, but I'm sure the principal is pretty much the same. Got a multimeter onto relay socket 12 and used the CE2 list/diagram. Got 12v across pins 2&4 and 4&6 but nothing from 3&4 2 Main Fusebox Start/Run Power 3 To ECU (Fuel Pump Turn-On) 4 To Fuse 18, Fuel Pump, Oxygen Sensor Heater 6 Main Fusebox Battery Power From 30B So guess a signal isn't getting from the ECU to the pump to tell it ignition is on. Or have I got this wrong? Again...useless with electronics :D Quote Share this post Link to post Share on other sites
Mark261288 10 Posted January 10, 2015 Hi, did you get anywhere with this? I'm having the same problem. Pump works but won't prime so car takes a few seconds to start. Which pins should be live when it's supposed to be priming? Quote Share this post Link to post Share on other sites
Bast 10 Posted January 19, 2015 (edited) Hey, sorry for the slow reply. Never actually got to the bottom of it, I believe it to be a problem with the ECU itself but without trying another ECU I can't be 100% sure. The problem was that the relay wasn't being triggered by the ECU when the ignition was live, the wiring between the fusebox and the ECU itself checked out, equally, the grounds from the ECU were all fine (unbolted, cleaned them up then re-attached) A final check I did was unplug the ECU and earth the pin 6 (Cant remember exactly) on the loom, which resulted in the pump priming on ignition live. Get the relay out and try both the ignition live (pin 2) and the ECU - Relay switch on (Pin 3 or pin g1/03 at the back of the fusebox) Check the wiring continuity between ECU and fusebox. Check you're earths at the Battery and at the back of the head of the engine (assuming its a VR6)Not sure if there's anymore. You Could check that the ECU is getting power by testing pins 38 (ignition live) and 54 (permanent live) on the ECU connector and and 1, 7, 10, 55 and 56 are all earths. You could also try the final check that I did above. I'll hopefully get hold of a spare ECU sometime soon to test further, without sounding odd, I really hope that's the problem :D Still have the issue of cutting out when low on fuel, but I think that's more an indication to the pump being on its way out or loose in its housing or something Edited January 19, 2015 by Bast Extra info Quote Share this post Link to post Share on other sites
Mark261288 10 Posted January 20, 2015 Im pretty much in the same situation as you. When i earth pin 6 on the ECU the pump fires up, so it isn't a wiring or relay problem. It seems the my ECU just isn't earthing pin 6. I tested all of the above pins for earth too and they were all correct except my pin 10 is blank.ill double check all of the main earths tomorrow.. Its beginning to drive me mad now. Let me know if you sort it before me. Thanks Quote Share this post Link to post Share on other sites
Spuddy 10 Posted July 5, 2015 Did this ever get solved. O have exactly the same issue with a 2.0 16v 9a engine. Ignition feed to relay ok Main Supply to relay ok Supply from relay to pump ok. Continuity between pin 3 on relay housing and pin 14 on my ecu ok Just no trigger earth from the ecu itself. Have checked all ecu earths. My car however wont run at all. So I've had to permanently earth the relay to get the car just to fire and move. Quote Share this post Link to post Share on other sites
Moshiko Levi 10 Posted October 31, 2015 Did this ever get solved. O have exactly the same issue with a 2.0 16v 9a engine. Ignition feed to relay ok Main Supply to relay ok Supply from relay to pump ok. Continuity between pin 3 on relay housing and pin 14 on my ecu ok Just no trigger earth from the ecu itself. Have checked all ecu earths. My car however wont run at all. So I've had to permanently earth the relay to get the car just to fire and move. i have the some problem for the last 4 years and i hat it !! my car is 20vt swapped 10 years ago and all was fine . 4 years ago its happend :( I have not found a solution so I started to change things - i installed New gas pipelines New fuel pump X2 New fuel relay X 3 ogignal ! New ECU new Power line from the pump to a new EBOX. New EBOX . still the some what it can be ? Quote Share this post Link to post Share on other sites
Yandards 0 Posted November 1, 2015 Er, the fuel pump on the VR does not prime on ignition in the run position folks, it only operates when the ECU signals the fuel pump relay to change over during the starting process. So you will never get a VR pump operating without the ignition on. Quote Share this post Link to post Share on other sites
Moshiko Levi 10 Posted November 1, 2015 (edited) Er, the fuel pump on the VR does not prime on ignition in the run position folks, it only operates when the ECU signals the fuel pump relay to change over during the starting process. So you will never get a VR pump operating without the ignition on. i had it untul 3-4 years ago one day its stopped :( Edited November 1, 2015 by Moshiko Levi Quote Share this post Link to post Share on other sites
