MervynG Posted January 4, 2016 Share Posted January 4, 2016 '57 plate 1.6 petrol Mondeo Mk 4 (owned fro new, no other problems, serviced, low mileage for year) refuelled 69 litres from nearly empty which then refused to start at the Sainsubury's petrol station. Just lurched 1 metre forward and apart from 2 hiccups, nothing. Towed it home and have discovered (by taking fuel line off in engine) that there is no fuel pressure. Engine turns but will not fire. Squirted brake cleaner into air cleaner and whilst squirting it would fire, suggesting electrics and engine ok. Central fuse box F22 20amp fuse on main board ok although it looked as if it had been hot as the edges of the legs were blackened. Green flag attended and their generic OBD scanner apparently showed no fault codes. So some help please.... 1/ Is there an inertia cut out on this model and, if so, where is it? 2/ What other devices can stop the pump from operating and how can I check them? 3/ Is there a complete system diagram anywhere such that I can evaluate the items that may be stopping the pump from running and how the power routes to the pump? 4/ Is the pump only accessible after lowering the tank? 5/ What is the layout on the pump and what can I check? Answers and any other advice very much appreciated. Quote Link to comment Share on other sites More sharing options...
iantt Posted January 4, 2016 Share Posted January 4, 2016 dont think theres an inertia switch, as it stopped after filling, it does sound like your pump has packed up, but check fuse f17 in engine bay, that fuse supplies the feed to the fuse 22 in the passenger footwell fusebox, that in turns powers the relay which im led to believe is part of the fuse box(body control module), then goes to pump . lowering the tank is required to check/remove pump there is a connector ,im assuming near the tank with 4 pin connector, with pump wires yellow/orange black/blue and gauge sender wires yellow/violet green/blue hope this helps you out Quote Link to comment Share on other sites More sharing options...
dezwez Posted January 4, 2016 Share Posted January 4, 2016 can you not get to the tank from under the rear seat Quote Link to comment Share on other sites More sharing options...
iantt Posted January 4, 2016 Share Posted January 4, 2016 Nope, not that I'm aware Quote Link to comment Share on other sites More sharing options...
MervynG Posted January 5, 2016 Author Share Posted January 5, 2016 Hi Ian, Thanks for the advice. I couldn't locate an inertia switch so thanks for confirming there isn't one. I checked all fuses in all boxes as the function of some (F7 – 5A – Relay coils) wasn't at all clear but will check F17 again specifically. Do you know which relay is involved as you say, 'the relay which im led to believe is part of the fuse box(body control module)' and some, like fuses, are unclear (R7 – 15 relay)? Do you know where these wires route? There are two bundles emerging from the front of the floor area in the boot (one left and one right) and some under the rear seat. If I could find them before lowering the tank I could test them. Do you or anyone have (or can send) a fuel system wiring diagram? 'lowering the tank is required to check/remove pump' Is this straightforward or a bad dream which leads to a nightmare? And I thought internal pumps rarely, if ever, failed? What about crankshaft rotation sensors and other potential stoppers? Rgds Mervyn Quote Link to comment Share on other sites More sharing options...
iantt Posted January 5, 2016 Share Posted January 5, 2016 Will be a nightmare now you got full tank of fuel. Think it could be garage job now. Dont know where the wires run to and from. Your going to have to try and figure that out, you now know the wire colours, yeloow orange is feed to pump and black blue is earth. And obviously feed will only be live for a short time with ign on without engine running. Im putting my money on pump/wiring connector on pump. Quote Link to comment Share on other sites More sharing options...
MervynG Posted January 6, 2016 Author Share Posted January 6, 2016 Thanks again Ian, I'll start by trying to locate the right part of the loom. If successful and issue unresolved I will then try and drain fuel. As a former professional aviator it is easier to get a wiring diagram for a B747 fuel system than it is for a Ford! Quote Link to comment Share on other sites More sharing options...
iantt Posted January 6, 2016 Share Posted January 6, 2016 Had a dig around and apparently there sometimes is an issue with the connector/ wiring on the tank sender/pump unit and connector melts , modified wiring harness and new pump unit. Ring your local ford dealer and enquire Quote Link to comment Share on other sites More sharing options...
MervynG Posted January 6, 2016 Author Share Posted January 6, 2016 Hi Ian Update: Found the cables under the rear seat right hand (driver's) side in a loom with several. Quite easy to spot as the black outer wrap had shifted leaving several gaps where the colours were easily visible. The two pump cables - orange/yellow and blue/black - are quite thick compared to the others which, given the 20amp fuse, is hardly surprising. Located my mutlimeter and recruited someone to turn it over (after attaching jump leads as many starts had part depleted the battery and I didn't want any other excuses for it not working). Pushed hard on the multimeter spikes, called for rotation and ................... it started immediately! So now I don't know if it was cables, ,connections, lack of supply volts, some other prohibitor or the pump. I suspect I'll have to wait until it happens again! Thanks again for your help without which I would have not had a clue. I will report back if/when there's a recurrence and when I figured out what it is. Quote Link to comment Share on other sites More sharing options...
iantt Posted January 6, 2016 Share Posted January 6, 2016 That's good or bad depending on how you look at it, good it started, bad you don't know why. Quote Link to comment Share on other sites More sharing options...
MervynG Posted August 11 Author Share Posted August 11 7 years on and still have the car and the no fuel pump issue still occurs every 8 months or so then when it decides to run, it runs happily for months! I need to end this torture. If fuel pump runs after ignition switch on all is fine. Obviously if it doesn't, for whatever reason, it won't start. But what is behind this? 4 months ago AA came and couldn't find the fault and despite hammering on the floor pan the pump wouldn't run for the normal few seconds after ignition on. Next day fault disappeared on its own - again - until this week. So, using Forscan Lite I have discovered that there are some DTCs: 2 in HVAC (B10B9:00-68 Blower Control and B10BB:00-68 Air Quality system. Maybe this was because the A/C/radio was switched off? 3 in IPC (U3006:16-68, U0401:68-28, U0415:68-28). There are no other error codes but the fuel pump doesn't run and the engine cranks but will not fire. U3006:16-68 says Control Module Input Power 'A' Circuit/Open Additional Fault Symptom: - Circuit Voltage Below Threshold and 'Previously Set DTC - Not Present at Time of Request', Module: Instrument Panel Control Module. U0401:68-28 says Invalid Data Received from ECM/PCM A and 'Previously Set DTC - Not Present at Time of Request' and Module Instrument Panel Control Module. U0415:68-28 Invalid Data Received from Anti-Lock Brake System (ABS) Control Module 'A' and 'Previously Set DTC - Not Present at Time of Request' and Module: Instrument Panel Control Module. All CAN bus voltages and resistance seem ok (6+14 61.6Ω, 3+11 61.7Ω, 1+8, 66.8Ω. 1 2.52V, 8 2.4V, 3 2.71V, 6 2.71V, 11 2.28V and 14 2.32V). If I put a multimeter across the orange/yellow and blue/black fuel pump wires on the floor under the rear r/h seat I do see a pulse of voltage for a few seconds after ignition on but on my old multimetter it only seems to be a volt or so and not 12v for a few seconds. Any more thoughts welcome please. Quote Link to comment Share on other sites More sharing options...
MervynG Posted September 2 Author Share Posted September 2 Update: Finally sorted. Took pump off and found terminals burnt. Annoyingly this is the precisely the same pump design I fitted in 2016. No improvements from Ford and terminals clearly can't handle the current. 1 Quote Link to comment Share on other sites More sharing options...
Monty3 Posted September 3 Share Posted September 3 Hi - glad you've sorted! Shocking to see those terminals... My 08 mk4 is currently having the same no start... Did you have to drop the tank to change the pump?.... or cut your way to it from above? Cheers! Quote Link to comment Share on other sites More sharing options...
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