Duratec fuel pump wouldn’t prime and car won’t start - SOLVED

[Philip G]

I was out for a long run today in R300 Duratec. Stopped to fill with up with fuel on way home and topped tank right up, “click click ...”. When I came to start, immobiliser light ok, the engine turned over but did not fire up.  Realised the fuel pump was not priming. After 30 mins of checking inertial switch, ECU plug etc, had to get my trailer to get the car back home.  I have removed a bit of the fuel from the tank.  I have removed boot floor room to get access fuel pump.  I am not great with electrics. I would really appreciate a quick test routine to determine what the problem is.  Many thanks  

Car is 2012 170 Duratec but with only 2,000 miles on it..

[SM25T]

Fuse ?

[Tazio]

Inertia switch?

[John Vine]

Agree about the fuse.  Normally 15A (blue), labelled M in the handbook, and located at the top of the lowest block of three fuses.

But if it's not the fuse, and as you already have the boot floor out, check the 12v pump supply.  The connector block should have four wires.  The supply is the thick yellow/green one.  If you have a multimeter, you can test for 12v in situ by back-probing the yellow/green with a needle (that is, by inserting a needle alongside the wire and into the connector from above), and then test for 12v between the needle and a suitable earth. 

JV

[Tom_Arundel]

Did you go over a bump going in to the fuel stop? could trip inertia switch

Some inertia switches have the wrong loom plug.....the plug does not lock onto the body and can come loose

[Philip G]

I have checked all the fuses and they look ok.  Switched some 15 amp around. IT STARTED. Probably three hours since I last tried.  However, when I tried to start again, no joy, just turning over despite me resetting mobiliser etc. Have reset inertia switch plug. Seems ok. Fuel meter is working  

I am away for a few days and will do the tests suggested by John on 12v supply mid week. 

 

[AdamQ]

I had a recurrent fuel pump problem and it turned out to be corroded fuse contacts - sounds like your issue might be similar ...

Hope you get it sorted out soon ...

[anthonym]

Yes I was thinking corrosion etc but a 2012 car? And only 3,000 miles. It’s practically new with no vibration heat etc to speak of.

How about applying 12 v direct (fused) to the pump (is it internal or external?) ? That’s the last thing I did (by which time me and malcolm (thank you!) had removed it from the petrol tank) and with hindsight it should have been the first. If it works, then it’s follow the circuit time. 

Is the earth on these a separate wire as opposed to relying on the chassis?

anthony

 

[John Vine]

...is it internal or external?

Internal. It hangs (approximately) vertically from the top face of the tank:

Is the earth on these a separate wire as opposed to relying on the chassis?

It's a separate wire that disappears into the loom, to be earthed along with others.

JV

[Wrightpayne]

If the car loom is same as a 98 car there is a crimped joint downstream of the inertia switch - mine was faulty at build and had the loom stripped and the joint soldered (by Classic Carriage).

If you rig up a +ve feed direct to the pump and it runs OK then the wiring (somewhere) is probably at fault.

Ian

[anthonym]

gosh that's an easy access. Mine's accessed from the side, meaning tank out.

I don't think anyone has mentioned which is the spot to try a 12v feed? #4 mentions it I think but not in the context of applying 12 volts - and I don't know this car... which will also test the earth.

If it's a case of chasing the connections you need a wiring diagram - JK has a good collection. I broke down I think five times with this problem last year, every time a different connection fault.

[Philip G]

Thanks guys. Will have some time on Wed to get my bearings and start the hunt. All posts really helpful. Thx. 

[John Vine]

You could apply a separate 12v supply to the yellow/green (YG168 below) using a back-probe, or you could detach the connector and apply 12v direct to the pin in the top of the pump assembly that matches YG168.  In the first, you'd be using (and thereby testing) the existing earth; while in the second, you'd need to add a separate earth to the pin corresponding to B10 below:

 

 

To remove the connector, press on this little tab:

JV

 

[NeilCSR]

I had a similar issue a year or so ago - single dodgy connector in multi core connector on MFR feeding pump relay.

Took ages to find but minimal time to fix.

 

[Philip G]

I recognise all the pics and instructions from John Vine. Assume I will need a power probe. I keep the car on the Isle of Skye so that will be for the next trip up in five weeks

The pump did prime and start engine last time I tried but then it didn’t when I retried two mins later  I’ll be trying again this evening.  So may be intermittent

From this evening I do have a few more days to check connections etc 

I have in my mind the only thing that changed between the engine running fine for two hours and the problem was engine off, filling the tank right up and attempting start five mins later. I suppose that is electrics  

Neil CSR, can you help me with what the multi core connector to the relay is ?  Is it base board they all plug into ?  How do you find the problem ?

Anthonym, it would be really helpful to understand the sort of places you found your issues with your five faults. 

Thx again all for taking the time. 

[anthonym]

hi, sorry, been out all day. Ok, but mine's a year 2000 K series.

Connector where

loom joins pump

the purple wire connector on front edge of bulkhead shelf that brings 12v to the ECU

into the inertia switch (fell to bits when removed)

the circuit from the engine bay to the fuse box and back, cut it out with a short "jump" wire. Never did find this one, but the new loom seems to have fixed it.  

I'm sure there was another.. I'll see if I can find the old thread. There was lots of suspicion of the MFRU but it was faultless.. ah that may be the fifth the 12v supply to that (one of I think 2)

However, the above is only really for inspiration as we can see from John's pics etc your car is different from mine. 

In my case the moral of all the stories was it wasn't parts failing it was connectors. Hence suggest test 12v to the pump to rule it out, or indeed in. Unlike me, save yourself buying a pump you don't need (and an alternator).

When "feeding" 12v round other parts of the circuit, sometimes they worked and sometimes not. VERY disconcerting. I did seem to be in a minority of one (never happened before) compared to using a meter to test for continuity etc rather than shoving 12v down wires to see what works - so mine is just experience and desperation when on tour, not skill!

The short version is follow the circuit and find the connectors. and wiggle everything..

there is a certain satisfaction in seeing 12v coming in one side of a connection and nothing coming out of the other, especially when it wiggles on and off.. that's "gotcha!"

p.s. interesting I just realised John says the 12v is yellow/green that is the same as mine.... let me think.. trick is to identify the order of current flow. What goes to which and I can't remember, but for example

12v supply to ECU to Inertia to Fusebox "in" across Fuse to Fuse "out" to pump (do NOT rely on that as I can't recall the correct order -I'll correct it if anyone can tell me, think MFRU is involved too, see #14 above ). Needs a wiring diagram or indeed someone may be along in a moment who knows.

the on tour test was take a piece of wire straight from the battery to the pump and see if it works (yes you should use a fuse), so wire dangled all the way over the roll bar... but you aren't on tour and desperate. 

Anthony

 

 

 

 

and later but not fuel:

alternator B+ at alternator, held only by the pvc  cover.

then when relooming found the positive cable to the battery distribution post disintegrated in Andrew's fingers..

[Philip G]

Thx Anthony .. appreciate you taking the time. 

[anthonym]

Hey no worries, very welcome. I have had limitless help on here myself. Not least when my fuel pump wouldn’t work one day without warning in S of France, one member rocked up armed with all the tools, spent two days with me _ then we went for a blat  :-).  Thank you EEK :-)

 

edit to say most of what I have learned has been done so you might say unwillingly, at remote roadside locations. Necessity is the mother of invention and leads to a dog’s breakfast under the bonnet :-)

[Philip G]

 

‘The car is running again after an hour or two of chasing connectors.  Pump priming and operating as normal.   I switched fuses and relays..  Relay  was clicking ok but I switched it anyway.  

I re-routed and loosened the wires going to the inertia switch as they a bit tight and reset the plug into te switch.   I removed the part of the loom with the pump connection and the plug that attaches the four wires  from pump to the loom.  I checked the wires for continuity.  All ok.  I notice that the wires coming out of connector to the pump are bent over by the floor so that might have had something to do with it.  Checked continuity of inertia switch, ok.

The car is very lightly used and kept spotless inside and out.  Connections we all in as new condition.

Put it all back together again and the pump primed and she started  

Tomorrow I am going to just check everything ok with immobiliser loop as last check.

I’ll give it a run again at the weekend to check all is well.

Hopefully sorted but now I know where I am looking for problems if it reoccurs  

Thanks to to all who have helped.

[Roy Blyth]

Philip, I noticed your comment about the wires in the connector to the pump.  When we finished building the car last year it would not start.  It turned over and everything electrical worked, except the fuel pump would not prime.  An auto electrician came and took a look and found that one of the pins in that plug was slightly bent.  Straightened the pin, plugged it back in and started first time!  Maybe yours is/was a similar issue..? 

[Philip G]

Thx Roy ... I took the car for a run this morning and then topped up with fuel and all seemed ok. Probably was a weak connection somewhere. A least I now know my way around the circuit. 

[John Vine]

Glad to hear it's fixed!

JV