Focus 1.8tdci engine issue qustion

eatcustard

eatcustard

eatcustard

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Any help here please.

When cold car starts and a plume of white grey smoke comes out of exhaust for about 5 seconds.

Rev counter goes from 750 rpm to 1200 rpm and is hesitant.
When I drive off it is still hesitant for about 10 seconds
Some times in a low gear as low speeds it hesitant for 1 second tops.
When warm it drives fine, pulls as it should.

On Friday after a run, it would not start for 45 mins, but I did the same Saturday and today, and it fired up fine.

No flashing glowplugs or other warnings on dash

Car is 2007 with 55k on clock, serviced 4k ago

I is booked into garage but not until Thurdsay.

any ideas?
 
I have exactly the same problem on my car mate, i have just replaced the glow plugs but noticed that cylinder 4 plug was damp when removed, i suspect that the injector is leaking and as such the fuel pressure is dropping when left. Mine is has the same rough running and white smoke when it has been left for a while once it is revved slightly its fine and will start no problems at all.
 
atpbx said:
Injector fault.
Click to expand...

What that man said :D

Just had exactly the same fault on my Mondeo TDCI and got a leak test done (30mins and £35) and found the No2 injector was overfuelling constantly (ie not shutting off just constantly pouring fuel into the chamber). Changed the injector for a £150 new one from eBay and it's cured everything.
 
ianh said:
What that man said :D

Just had exactly the same fault on my Mondeo TDCI and got a leak test done (30mins and £35) and found the No2 injector was overfuelling constantly (ie not shutting off just constantly pouring fuel into the chamber). Changed the injector for a £150 new one from eBay and it's cured everything.
Click to expand...

Sounds interesting, but would the engine run fine when hot and would it cause the car to not start when warm?
 
ianh said:
What that man said :D

Just had exactly the same fault on my Mondeo TDCI and got a leak test done (30mins and £35) and found the No2 injector was overfuelling constantly (ie not shutting off just constantly pouring fuel into the chamber). Changed the injector for a £150 new one from eBay and it's cured everything.
Click to expand...

out of interest mate was your injector a siemens one? If so did it need coding? i have one here that i am going to do but i read conflicting reports of coding being required or not.
 
eatcustard said:
Sounds interesting, but would the engine run fine when hot and would it cause the car to not start when warm?
Click to expand...

Yeap, the lack of pressure in the rail (due to one injector being "open") causes difficulty starting but once started the high pressure fuel pump (HPFP) is being fed from the alternator (instead of the battery) and will provide a higher pressure which allows the rail to provide enough fuel to overcome the drop from an open injector. When starting on battery your HPFP should be producing about 250-300bar and during driving on alternator it can go upto 1600bar but with an open injector that battery powered idle pressure will drop to say 150-200bar which is what causes starting issues.

fish said:
out of interest mate was your injector a siemens one? If so did it need coding? i have one here that i am going to do but i read conflicting reports of coding being required or not.
Click to expand...

Mine were Delphi and if it's a new injector you need to recode the cars ECU with the new injectors "Null" code (printed on the injector) as this will be different from your original injector. If it's the original one thats only been cleaned then the original code should still be OK. However if they've changed any part of the injector then it'll have a new code just like a new injector.
 
ianh said:
Yeap, the lack of pressure in the rail (due to one injector being "open") causes difficulty starting but once started the high pressure fuel pump (HPFP) is being fed from the alternator (instead of the battery) and will provide a higher pressure which allows the rail to provide enough fuel to overcome the drop from an open injector. When starting on battery your HPFP should be producing about 250-300bar and during driving on alternator it can go upto 1600bar but with an open injector that battery powered idle pressure will drop to say 150-200bar which is what causes starting issues.
Click to expand...

Thanks for that, have a virtual beer on me :D
 
Head gasket problems aside, white smoke from a diesel is down to raw fuel coming out of the exhaust. Surely if there is an injector issue then this would be happening all the time, not just at start-up?
 
The white smoke at start up is all the unburnt fuel from the open injector which is getting most of the fuel from the fuel rail (path of least resistance for the 200bar startup) whilst the others are slightly starved until it finally starts. Then the HPFP can start to supply enough pressure (1000bar+) to the rest of the injectors that the one leaky one can no longer taking all the pressure out of the rail so now the exhaust gases from the other 3 cylinders, which are now running well, mix in enough that you'd only notice it if you put your foot down or at night when lit up by the headlights of someone following you.

Thats for Ford TDCI's, other engines may work differently.
 
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