2015 Pug 2008 1.6 diesel hard starting

[Guineafowl]

Mate’s car. He’s noticed slightly longer cold cranking times, after recently doing a long journey.

I know it’s summer, but I had a quick check of the glow plug fusible link (ok) and just barely reached a test light into one of the glow plug connectors. Glow plugs are not being powered at switch-on.

Glow plug relay is buried, and I’m not even sure it’s worth pursuing given the hot weather.

Any pointers appreciated.

 

[AVI_8]

French cars are not my thing, but at this time of year I wouldn’t expect to see the glow plugs operating on my cars, only on a cold winters day.

 

[Guineafowl]

French cars are not my thing

Snap.

DTC P2291 - rail pressure rising too slowly on cranking.

 

[Ubique]

As above, check for DTC's first - has there been any noticeable change in fuel consumption?
The problem won't be the glow plugs with a warm engine, is it starting OK with a cold engine?

As an aside, glow plugs on vehicles at least of EU2 emissions standard will operate for up to a couple of minutes after starting to help initial warm up and therefore lower the cold start emissions, just because the glow plug indicator isn't on, doesn't mean the glow plugs are inactive, it just means 'start engine now'.

 

[The_Yellow_Ardvark]

Pugs glow plugs are switched on at second click . When the icon is lit.

Check for battery voltage at the common connection when the icon is on.
Then it should go out. The volts will decay.

If present check the resistance of each plug.
Pugs will go sluggish when one or more have gone open circuit.

If they have failed they are easy to replace.
I advise to get the correct glow plug socket.

 

[Guineafowl]

As above, check for DTC's first - has there been any noticeable change in fuel consumption?
The problem won't be the glow plugs with a warm engine, is it starting OK with a cold engine?

As an aside, glow plugs on vehicles at least of EU2 emissions standard will operate for up to a couple of minutes after starting to help initial warm up and therefore lower the cold start emissions, just because the glow plug indicator isn't on, doesn't mean the glow plugs are inactive, it just means 'start engine now'.

Yes, not convinced by glow plugs. I checked power at one glow plug connector, with test light, when key switched to II. None. Hot day though.

Seems to be cold(ish) morning starts. P2291 code appears relevant.

I’ll get him to check fuel consumption. Are you thinking leaky injector when cold? I’ve got a cheapo leakback test kit.

 

[knighty]

Snap.

DTC P2291 - rail pressure rising too slowly on cranking.

don't freak out, check the small things first....

check for air in the fuel line and change the filter


fuel rail pressure errors are notorious for being misleading

 

[Ubique]

Fuel filter should be changed and bled through fully as a diagnostic elimination, now I've re-read your original post I would initially be thinking that a 'longer journey' could include filling or topping up the fuel tank so along with changing the filter, you need to be draining the old one to check for water or other contaminants to either confirm that as the cause or rule it out. If you can, temporarily put a piece of clear pipe between the fuel filter & the HP pump to check for air ingress downstream, otherwise, take the inlet pipe from the fuel filter and (with someone else turning on the ignition) discharge the pipe into a container & check for air bubbles. I've changed a few volume control valves, injectors and HP pumps, all of which can give the symptoms but are a much rarer occurence compared to a blocked fuel filter.

 

[premmington]

Fuel filter should be changed and bled through fully as a diagnostic elimination, now I've re-read your original post I would initially be thinking that a 'longer journey' could include filling or topping up the fuel tank so along with changing the filter, you need to be draining the old one to check for water or other contaminants to either confirm that as the cause or rule it out. If you can, temporarily put a piece of clear pipe between the fuel filter & the HP pump to check for air ingress downstream, otherwise, take the inlet pipe from the fuel filter and (with someone else turning on the ignition) discharge the pipe into a container & check for air bubbles. I've changed a few volume control valves, injectors and HP pumps, all of which can give the symptoms but are a much rarer occurence compared to a blocked fuel filter.

+1 - I would go for fuel filter first.

 

[Guineafowl]

There was a dribble of diesel coming down the fuel filter drain hose, and possibly air leaking back up, related to a damaged O ring.

Sadly, the Bosch filter I got didn’t come with a replacement, but it seems to have seated for now.

O ring at the bottom of thing on the right.