It Dies At The Slip Road Lights

[AlanSalop]

The Car - Focus '09 plate 1.7 TDCI Zetec 115, >30k miles.

Have scanned the last few months postings for anything similar and would appreciate any suggestions.

The Symptoms -

After cruising for say 1 hour on the motorway at approx 2k revs for economy I take the exit and slowly reduce speed up to the lights at the top of the slip road and stop - the engine dies and won't restart. The first time this happened I managed to get over the lights before it quit and park on the side. I called the RAC and the guy arrived after 45 mins and plugged in his diagnostic laptop. The fault he found was low fuel pressure. This would increase as you turned the engine over, it would fire, the pressure would drop and it would die. After trying various things he removed the low pressure fuel line while i turned it over and it started. He suggested the fuel sensor but it was giving readings. No further problem for the remainder of the journey, performance perfectly normal.

On the return journey and after stopping without any problem at services on the way I took the slip road for my exit and again it died at the lights. I tried removing the low pressure fuel connection but it did not start. After about 15 mins of waiting and cranking it restarted, again no further problem for that journey.

I decided to try going down through the gears on the exit slip road on a recent motorway trip of over an hour in case it was some kind of tick-over failure. ON the way out no problems but on the way back it did it again in exactly the same conditions. This time it restarted after just 3-4 tries and I was off home.

The car had a 25k service last June but the documentation does not indicate what was done to the fuel filter if anything.

Is there a fuel return valve that lets excess fuel back into the tank that could be sticking - what does it look like?

I really like this car, it handles well and has all the poke I need but this fault is not good if a symptom of a deeper problem especially if the bad weather is heading our way.

Any ideas gratefully received.

[jeebowhite]

Start by checking the fuel filter sounds very similar to what I had ages ago!

[Preee]

Second that , start with the easy stuff , fuel filter and air leaks , if there is an air leak then it could be sucking air into the system.

[jeebowhite]

Indeed, as you come off the main roads, your exhaust will be hot, all materials will expand and temporarily seal any cracks, when you stop moving, the cool air starts to gather, the metal starts to contract and any cracks are opened up, letting air in and being injected into the engine...

[AlanSalop]

Pree, jeebowhite

Thanks for those suggestions - so what you are saying is that the air could be getting sucked into the fuel lines and accumulating so that it dies when the revs drop? or have I got the wrong end of the stick ?

The thing that gets me is that the conditions are so specific, added to the fact that when it first happened I was heading for LHR to catch a flight!

[jeebowhite]

Correct, I had the issue on my Focus a few years back. I was driving down the motorway on a snowy day, as I got to 2000 revs (TDCI) I was fine, but the second my needle passed that, it killed the engine. The Fuel Filter Housing had a massive crack in it, the days before when it was warmish, it expanded and wasnt a problem, but because I was driving in Ice and Snow, the cold kept the crack open, revs went up, vacuum increased and sucked in the air into the fuel line which was then sucked / pushed along to the engine and injected into the cylinder. Unfortunately a squirt of excess air and lack of fuel didnt burn very well, combusion stopped and engine shut down.

Oh, and welcome to the forum! I didnt see before hand being on the phone you were a new member :)

[Preee]

When wifey had an Escort Diesel she ran it out of fuel , after i got it going it kept cutting out "air" so i removed a pipe return from the injector and managed to get the air out , ran fine for a few days then kept either cutting out at low revs or trouble starting when if it was hot.

When i removed the return pipe to clear the air , it had split and kept sucking air into the system , once replaced it was fine , Go on a "Sniff" test see if you can smell diesel anywhere under the bonnet , or like Jeebo says could be else where.

Filter is the first thing though.

and welcome to another Shropshire guy , not many of us on here lol

[Leemaxd]

Happened to me last year same thing, was the fuel filter, someone on here told me to change the fuel filter and I didn't have time so I put it in ford and it cost me about £170 if I remember, but could of been alot cheaper if I would of changed it myself :(

[martyntdci]

was the fuel filter, someone on here told me to change the fuel filter and I didn't have time so I put it in ford and it cost me about £170 if I remember, but could of been alot cheaper if I would of changed it myself :(

if you go for a filter insert will knock you back 25 notes max, and 30mins of your time, a hour max if you run into air problems....

[AlanSalop]

Thanks Guys-

Temp -2.5C locally this morning , I took it out for a local run and no problems. On return had a good look under bonnet with the benefit of bright sun but no signs. I will try to trace the lines back to the tank sometime this week when I can get under it.

martyntdci- you mentioned possibility of air problems - do I need a "Haynes" to deal with bleeding it? is there guidance on the web or this site?

[martyntdci]

there is a bleed valve ontop of your fuel filter housing, i think its a 8mm/10mm plastic nut. as ive read you carnt crack the injectors off to bleed the system....... the only way i did it was a little pipe and give it a suck to see if any bubbles appear