MB 2.3 Duratec HE stalling possible fuel pump issue

KarlInKG · 03-07-2018, 09:00 PM

Ok so a bit of a saga. Two weeks ago my MB 2010 Mondeo started randomly stalling. It would start again fine, sometimes straight away sometimes after a delay.

I took it to the local Ford dealership who diagnosed a P0744 fault code (intermittent TCM fault) and told me the vehicle is a write-off. Basically the cost of a new transmission or even a 2nd hand one takes it beyond economical repair. I was pretty depressed but something told me they must be wrong.

I took it to an independent mechie who came back with the same result. He said there are a lot of random codes popping up but the P0744 keeps coming back every time. Mind you he didn't get to see it stall.

Ok so I took the car out of the independent's workshop and basically couldn't get it home, it would initially stall every 300m or so until it finally wouldn't start at all. I got it taken home on the transporter while I thought about what I was going to do with it.

So, after a lot of pondering... Prior to taking it to the independent I got stuck in the Bunnings car park - it stalled and on restarting ran like a dog, as if only running on 2 cyl's, not enough power to move, it stalled again after running like that for about a minute. After about an eterity (traffic was building up behind me as I was at a roundabout in the carpark) it finally started properly again so I raced over the round-about and into an vacant area of the car park. After driving around there a few minutes I prayed solidly as I drove it home - no more stalling that day. The next day of course it ran fine in taking it to the independent and then stalled as I mentioned above.

So, at home I have been trying it over the past few days. Yesterday I noticed as I was trying it in the dark that just prior to stalling the interior light would fluctuate in brightness. Eventually last night it stopped for good. Now when I turn on the ignition there is no 1 second buzz of the fuel pump starting. So, I'm strongly suspecting I have the bad fuel pump connector problem others on the web have had. I checked the fuel pump fuse tonight and it is intact.

I really want to have a look at the loom and connector for the fuel pump but have not been able to find anywhere where it is located on the MB 2.3 Duratec HE - Aug 2010 MB. I'm starting to get a bad feeling that I may have to drop the tank to get at it. Can anyone tell me how to access the fuel pump on this model?

I'm posting this same post on Ford Australia Forums.

cobrin · 04-07-2018, 03:13 PM

I'd have thought there'd be an inspection cover above the pump in the car body, and that's where you'd get to the pump. Seeing as you want to also access the harness I'd say it's a drop the tank kind of deal. You don't have to remove it fully (I'm not sure what setup it has) but it's been my experience that the tank straps have an anchor point and the other end the bolted fixture. So undo the bolted end and tilt/lower it down till you have the access you need. That or take it out, its up to you.

KarlInKG · 04-07-2018, 09:28 PM

Thanks for your reply @cobrin, yeah I really would have expected an access hatch above the tank. Today I took the rear seat out and was pretty disappointed that there is no access at all above the tank, completely closed there. The only access hole is in the boot space where the wiring loom goes through to the tank.

I have managed to find a couple of web links pointing me to the fact that i have to drop the tank to get the pump out. So this afternoon I went and bought a 54 litre plastic rolly bin as I'll have to remove the filler pipe and let the fuel (about ½ a tank full) flood into the bin before I drop it. All set to give it a go tomorrow.

KarlInKG · 09-07-2018, 11:44 AM

For anyone following this thread in the future see more comments here:
https://www.fordforums.com.au/showth...45#post6159245
and here:
http://www.fordaustraliaforums.com/f...uel-pump-issue

cobrin · 09-07-2018, 11:17 PM

yeah better to get a decent quality unit than the cheapest one going around. Good luck.

toyota lexcen · 17-07-2018, 11:12 AM

have you got it in?

not sure if the failure is to do with the pump assembly or the fact the fuel filter cannot be changed

the ford moco one lasted 115,000kms for me,

can a fuel filter go the life of the car? or is it to be changed even in the mondeo

i may choose a genuine pump assembly if mine goes early, but i thinking of changing it at 70-80,000kms

KarlInKG · 22-07-2018, 07:07 PM

Quote:

Originally Posted by toyota lexcen

have you got it in?

Yup, new one installed. I went for the OEM a VDO (Siemens) but ordered it through an Ebay seller who drop shipped from Adelaide. Turns out it is exactly the same unit as what was in the car but the new one has the name FoMoCo and Siemens ground off for some reason. Paid $384. My Mondy has been resurrected and purrs again

One problem I did have is on my first fill at the bowser I had a significant fuel leakage. Seems to be related to something at the top of the tank as it's not leaking now. After the pump clicked once I waited a few seconds and continued filling (as I usually do) it then kept going for another 10 litres or so which baffled me as the fill then went up to 68 litres and the tank was showing ¼ full when I pulled in to the station. I was trying to work out how this could be and wasn't smart enough to stop filling at around 50 litres. When I got in the car I smelled petrol and so got out and checked at the back of the car. It was raining, with water everywhere but checking the ground revealed there was petrol there - I'm guessing at least 5l must have spilled, maybe 10 even. So I let the station attendant know there had been a spill and gingerly drove off. So, since then there is no leak, none now so I'm thinking it's something at the top of the tank which is odd because I know I checked the tightness of the pump retaining ring and the connections. I haven't refilled the tank, I'm waiting till it runs down to about ¼ again and I'll have to drop the tank and re-check everything. Still a bit mystified. Wondering if it's possible that I'm getting a back-feed out of the top of the tank into the evap canister and out through the breather on that - I have no idea how that canister works but wondering if in draining the tank I damaged a seal in it. The other possibility is the seal around the pump being damaged, it looked in good condition and a new one doesn't come with the pump so I didn't bother changing it (new one from Ford is $210 or from Ebay $180). I think what I'll do first is drop the tank, fill it with 20l or so of petrol and tip it on its front edge so the pump is covered and will show if there is a leak around the pump. If not, will scratch my head and try and think what to do next.

Quote:

Originally Posted by toyota lexcen

can a fuel filter go the life of the car? or is it to be changed even in the mondeo

i may choose a genuine pump assembly if mine goes early, but i thinking of changing it at 70-80,000kms

I read somewhere in all my searching that the fuel pump in the Mondeo petrol models is considered a non serviceable item, designed to last the lifetime of the vehicle. Given that the filter is integral to the pump they consider the filter should never need to be changed. My pump still worked fine, just like others who have had this issue it's just the connection on the top of the pump that fails. The condition of my filter was pristine as well, no signs of clogging or debris in it at all so I'm guessing they're correct in that aspect. Shame they didn't design the electrical connector very well though. It's be worth you dropping the tank at 70-80,000kms as you suggest and just unplug the connector at the top of the fuel pump and have a good close look for any signs of arcing on the pump power pins.
Here's a pic of mine: