New member - Old problem?

[bobbler]

Hi all,

I've been following this forum for quite a while trying to find answers for my 2011 MK7 2.2 TDCI starting issue and hoping someone can help before I decide to burn it haha

I've only owned it for about 5 months and when used regularly it has been great but recently it seems to be having a problem starting after being left overnight. It will start and die a few times until it finally catches and will then run and start all day no problem. I can't find any fault codes, there was one for BCM error but I think that was caused by a very wet day where the engine management and abs lights came on and the speedo stopped working but once reset they haven't reappeared.

I bought it with 124k miles and the tickover was hunting so it has already had a new Denso SCV and PRV with pump learn and a full service with oil and fuel filters.

Please help.

[knobby1]

Hard to start after sitting a few hours or overnight is often an air leak in the low pressure side of the fuel system, air leaks in and the fuel siphons back to the tank...it then takes time and long cranking to suck it back up to the pump.

Have you checked the fuel filter first thing in the morning to see if it's empty.??

Poorly injector leak-off lines and O-rings are quite common. The filter head is also prone to cracking and letting air in, also check the four filter head supply/return lines and their connector O-rings for leakage.

All relatively easy and free to check.

Lord Knobrot

[bobbler]

I've not had a chance to pull the filter off yet but will get that done asap. I should be back with the van mid-week so will check the filter and lines and hopefully report back with good news.

Thanks for the advice

[bobbler]

A bit of a late update but here goes after the van was supposed to be away for a week for some cosmetic work and I didn't see it again for over 4 .

Since getting the van back the problem is getting progressively worse, I can now only leave it for around 4 hours before needing to crank the engine a few times with it starting and cutting out before it will catch and keep ticking over. Sometimes I can leave it overnight and it will start the next morning but this is getting rare.

I checked the hoses and couldn't see anything so I swapped the injector leak off o-rings which didn't work either. The fuel filter is genuine ford and I can't see any signs of leaks around the housing.

I took it to my local mechanic who also checked a few things -

Injector leak off - OK
Injector pressure - OK
Cam / Crank sync - OK

He diagnosed the EGR may be sticking so it was blanked off and mapped out.

Got up the next morning and the problem is still there, I plugged in FORSCAN and a couple of error codes popped up but they may be down to the ELM327 lead I'm using (https://www.ebay.co.uk/itm/282534776686 ) - U0140 lost communication with BCM & U0155 lost communication with instrument panel cluster control module.

The only other thing I've noticed recently is the injector closest to the fuel pump seems to be slightly wetter than the others (injector 4). Could this be linked or am I starting to clutch at straws?

Thanks

[knobby1]

A bit of a late update but here goes after the van was supposed to be away for a week for some cosmetic work and I didn't see it again for over 4 .

Since getting the van back the problem is getting progressively worse, I can now only leave it for around 4 hours before needing to crank the engine a few times with it starting and cutting out before it will catch and keep ticking over. Sometimes I can leave it overnight and it will start the next morning but this is getting rare.

I checked the hoses and couldn't see anything so I swapped the injector leak off o-rings which didn't work either. The fuel filter is genuine ford and I can't see any signs of leaks around the housing.

I took it to my local mechanic who also checked a few things -

Injector leak off - OK
Injector pressure - OK
Cam / Crank sync - OK

He diagnosed the EGR may be sticking so it was blanked off and mapped out.

Got up the next morning and the problem is still there, I plugged in FORSCAN and a couple of error codes popped up but they may be down to the ELM327 lead I'm using (https://www.ebay.co.uk/itm/282534776686 ) - U0140 lost communication with BCM & U0155 lost communication with instrument panel cluster control module.

The only other thing I've noticed recently is the injector closest to the fuel pump seems to be slightly wetter than the others (injector 4). Could this be linked or am I starting to clutch at straws?

Thanks

When the lines, filter or filter housing leak, they don't leak fuel out but do leak air in. The whole low pressure side of the system is under a very slight vacuum as it has to suck the fuel up from the tank, any air ingress will allow the fuel to siphon back to tank....the filter housings are also known to crack and leak air in.

Lord Knobrot

[bobbler]

Took the filter off again yesterday after the engine had been stood for an hour or so to find it was only half full. I noticed the seal was dry too so I've tried wiping a bit of diesel on it before refitting to see if that helps.

I would like to make a pipe to bypass the filter from tank to pump and check it's not the housing letting in air, can anyone tell me the name/size of the fittings I need to buy to connect the 2 pipes together?

Thanks

[knobby1]

Took the filter off again yesterday after the engine had been stood for an hour or so to find it was only half full. I noticed the seal was dry too so I've tried wiping a bit of diesel on it before refitting to see if that helps.

I would like to make a pipe to bypass the filter from tank to pump and check it's not the housing letting in air, can anyone tell me the name/size of the fittings I need to buy to connect the 2 pipes together?

Thanks

Never use unfiltered fuel...the pumps and injectors don't take kindly to dirty fuel, most of the water and crap sits in the bottom of the tank and this is normally where to fuel pick-up is, the filter usually filters this out before it gets to the pump....if you must, run a fresh container of clean fuel straight to the pump..he

Lord Knobrot

[bobbler]

Took the filter off again yesterday after the engine had been stood for an hour or so to find it was only half full. I noticed the seal was dry too so I've tried wiping a bit of diesel on it before refitting to see if that helps.

I would like to make a pipe to bypass the filter from tank to pump and check it's not the housing letting in air, can anyone tell me the name/size of the fittings I need to buy to connect the 2 pipes together?

Thanks

Never use unfiltered fuel...the pumps and injectors don't take kindly to dirty fuel, most of the water and crap sits in the bottom of the tank and this is normally where to fuel pick-up is, the filter usually filters this out before it gets to the pump....if you must, run a fresh container of clean fuel straight to the pump..he

Lord Knobrot

Ok thank you. I'll pick up some fresh fuel today, a new Jerry can and feed the engine straight from the can. Can the connections be bought over the counter or do I need a local breakers?

[bobbler]

Been a few more weeks so thought it would be an idea to update this post. The van is getting better but I'm not 100% yet.

I swapped out the fuel filter housing for a new genuine replacement - no change
replaced the genuine filter with another just in case - no change
fuel sensor has been replaced along with rail as old one was stuck and injector seals have been replaced, while the mechanic was in there he noticed a rocker arm had slipped so sorted that at the same time - sounds better but no change

Today I've had the fuel pump replaced with a known good used pump (idea is existing pump will be rebuilt if it works), pump learn etc. - so far it runs smoother but time will tell if it helps the starting issue.

Driving it around tonight had me wondering, is there a better time to run a pump learn i.e warm or cold engine? Would running a pump learn with a cold engine possibly help with cold starting or wouldn't it make a difference?

Thanks

[TheCake]

pump learn will only run if CHT is above 65degrees c so its best to do it closer to 80degrees as the engine may get too cold for parameters during the learn.

[MagicAlex]

Hello all, I’m watching this post keenly. I’ve got a 2007 2.2 with a similar issue. Hope you get to the bottom of your problem!