T5 - stalling on hot start up

[850Chris]

Recently developed a fault whereby on hot start up the engine will stall immediately after firing. Also does it very occasionally on a cold start. I've discovered that a small bit of pressure on the accelerator solves the problem and once it's fired properly then drives absolutely normally.

Had 118,000 mile service today which I was hopeful may fix, but no such luck. A diagnostics was run as part of service and no fault codes stored. Any bright ideas? I'm thinking fuel supply issue?

[cheshired5]

I'd say the obvious and easy starting points would be fuelling caused by a faulty coolant temp sensor or it could be an air issue caused by a sticking idle valve/throttle.

[Orca2]

Recently developed a fault whereby on hot start up the engine will stall immediately after firing. Also does it very occasionally on a cold start. I've discovered that a small bit of pressure on the accelerator solves the problem and once it's fired properly then drives absolutely normally.

Had 118,000 mile service today which I was hopeful may fix, but no such luck. A diagnostics was run as part of service and no fault codes stored. Any bright ideas? I'm thinking fuel supply issue?

I find taking the T5 out for a good kicking keeps everything working , they seem to run better after a good booting. Mine is on 182k and never gives any trouble at all.

[850Chris]

I find taking the T5 out for a good kicking keeps everything working , they seem to run better after a good booting. Mine is on 182k and never gives any trouble at all.

The old 'Italian tune up'. She gets a good one of those every once in a while but, sadly, to no avail in this instance.

[Welton]

Have you ever replaced the Fuel Pressure Sensor on the end of the fuel rail? not saying this is the fault but it seems to be a maintenance item on these (just done mine at 78K miles) I was getting an occasional hold-back under acceleration.

Other stalling culprits can sometimes be the crank sensor (or it's wiring) as the ECU doesn't 'know' that the engine is turning. I mustard mitt it's not really a common fault on the T5 to my knowledge.

Keep us informed please.

[850Chris]

FPS was replaced fairly recently as was the MAF (and TCV & MAP for that matter) but think your suggestion of Crank Position Sensor worth following up on. A bit of Google research has shown a failing crank sensor to be a common culprit of starting issues and also impacting on general engine performance - which could explain why a Diesel Insignia was almost keeping ground with me the other day! Also appears that a failing crank sensor will not always log a fault code. I see PFS sell new sensors for £60. Not exactly cheap but it won't break the Bank either so maybe worth a shot? At least if it's not this, it will be one more new sensor in the system. Do you know what's involved in changing the crank sensor?

[Welton]

No I'm not sure where it is to be honest, they very often 'look' at the ring gear from being mounted on the bell housing. You might even get away with cleaning it even?

[850Chris]

Found it! It's on the transmission bell house below the air box unit. Aside from getting the air box out ( which I've done before and is a right pain), looks fairly simple.

[Welton]

Nice one, let us know how you get on.

[850Chris]

Fitted the new crank sensor today which appears to have sorted the hot starting issue. Thanks for the pointer Welton.

Fairly simple job. Took me about 40mins all in including a cup of tea. Air box doesn't even have to come all the way out - can just tilt to one side. Crank sensor quite hard to spot as is partly hidden by a coolant hose which runs below air box. Other than that - no issues.

Fingers crossed that's it!

[zoliS60]

Fitted the new crank sensor today which appears to have sorted the hot starting issue ... Fingers crossed that's it!
I'm just curious: do you have still this issue - or the crankshaft position sensor was the culprit?

[850Chris]

Not had any more problems since changing the crank position sensor.