Intermittent starting when hot (Diesel engine)

[moparopkop]

My t4 transporter 1.9td has started to play up when its been driven and warm....
If I turn it off it won't start again but will after a few mins of trying.....ive replaced the leak of pipes done a service fuel filter oil oil filter air filter etc.....new battery

Many thanks....

 

[Burt2000]

Sensor issue? Crank or cam sensors can cause intermittent warm starting issues, I had that in the past with an Impreza. I would get it scanned for any fault codes and go from there.

 

[BobSpounge]

Crank sensors can break down when hot. More common though is some of the 1.9tdi engines have a hot start map where the ECU won't allow the engine to start unless it sees a certain RPM when cranking. A lazy battery or failing starter motor can then prevent a hot start as the RPM's aren't high enough when cranking. When the engine cools down the ECU uses a different map and the engine will fire right up.

 

[Dandy]

Coolant temp sensor alot of the times.

 

[56oval]

Could be an intermittent fault with the anti theft solenoid on the injection pump. When it fails to start spray some easy start at it. If it kicks you know its not delivering fuel.

 

[paddyirishman]

Sounds like the cam position sensor. Would the engine cut out when driving sometimes as well?

 

[moparopkop]

Could be an intermittent fault with the anti theft solenoid on the injection pump. When it fails to start spray some easy start at it. If it kicks you know its not delivering fuel.

Can hear it click....although I haven't listened for it when it dosent because I'm always on my own and need something to turn the key while I listen

Sounds like the cam position sensor. Would the engine cut out when driving sometimes as well?

No it hasn't....was told crank sensor by someone....to be honest I've had about 5 different answers to what it could be

 

[paddyirishman]

My cam sensor gave bother, hard to start sometimes but would randomly die out when driving. I'd be looking towards the starter and battery.

 

[moparopkop]

My cam sensor gave bother, hard to start sometimes but would randomly die out when driving. I'd be looking towards the starter and battery.

Starts everytime in the morning perfectly....brand new battery last week

 

[DJMCA]

Passats are well known for hot start issues so depending on engine this may be the same

Starter is the issue for them, a lot of mappers can do something to fix this

 

[moparopkop]

Passats are well known for hot start issues so depending on engine this may be the same

Starter is the issue for them, a lot of mappers can do something to fix this

1.9td abl.....wouldn't pull ya outa bed

 

[DJMCA]

Not sure on that code but i know its the PD engines that seem to suffer in the Passats

 

[Dandy]

1.9td abl.....wouldn't pull ya outa bed

Is that the the old style mechanical style fuel setup on yours, theyve no ECU control over fuelling etc

 

[moparopkop]

Is that the the old style mechanical style fuel setup on yours, theyve no ECU control over fuelling etc

Yes

 

[ace275]

1.9td abl.....wouldn't pull ya outa bed

My old T4 2.4d wasn't any better. At least you have boost to turn up

Does it have the pump timing advance lever like an old choke? Pump timing could be out on it. Does it make any difference whether it's pulled?

Other option could be a poor stop solenoid. Don't think these have much more going on after that other than a coolant temperature sensor for the dash. Stop solenoid could be a good possibility TBH.

 

[moparopkop]

My old T4 2.4d wasn't any better. At least you have boost to turn up

Does it have the pump timing advance lever like an old choke? Pump timing could be out on it. Does it make any difference whether it's pulled?

Other option could be a poor stop solenoid. Don't think these have much more going on after that other than a coolant temperature sensor for the dash. Stop solenoid could be a good possibility TBH.

It does have the pump advance...
Would a coolant temperature make it not start?
I'm getting a click from the stop solenoid I haven't investigated if I am when it won't start as I'm on my own usually and hard to do on my own

 

[ace275]

I wouldn't think the coolant temperature would make it not start, as I don't think there is anything to control from that input. There is a coolant temperature sensor that feeds the Instrument Cluster, and a fan switch. Not sure if there is another sensor for coolant temperature.

I'd guess the solenoid is clicking when cold, but sticking when warm. Hard to hear at the time of course without a second pair of hands to do the ignition. Not sure if it clicks on and off with the ignition or not, without starting?

Try it with the pump advance in or out to see if it makes any difference next time it happens as it's quick to try, though I imagine it'll not make a difference