Hot starting my 1.9 TDI Sharan

**1.9 TDI Sharan** · 10-12-2007,05:24 PM

May have posted in the wrong place so have put a link here just in case.

https://www.vwaudiforum.co.uk/forum/s...ad.php?t=21491

Basically am having trouble starting the engine when hot. Cold is fine, no probs. When hot, turns for ages before firing.

Am looking to hook up to a Vag Com unit to see whats going on...any advice?

**kenney** · 10-12-2007,07:09 PM

Hi, sounds like a possible fault with the temp sensor

**1.9 TDI Sharan** · 10-12-2007,09:34 PM

Originally Posted by kenney

Hi, sounds like a possible fault with the temp sensor

Would something like this show up on VAG COM?

**kenney** · 11-12-2007,11:35 AM

Hi again usualy but not always,it might sound stupid,but rather than use a lot of time trying to find the fault,especially if it is not logged in the ECU,with the symtoms you have it is quicker to just replace the sensor.99 times out of 100 it is the sensor and if it should be 1 in a 100 then that is when the real problem starts.

**1.9 TDI Sharan** · 11-12-2007,07:54 PM

Originally Posted by kenney

Hi again usualy but not always,it might sound stupid,but rather than use a lot of time trying to find the fault,especially if it is not logged in the ECU,with the symtoms you have it is quicker to just replace the sensor.99 times out of 100 it is the sensor and if it should be 1 in a 100 then that is when the real problem starts.

Thanks Kenney, will add a temp sensor to my brake light switch order.

**cbrpaul** · 12-12-2007,03:40 PM

Engine code and year of your sharan pls ?

**1.9 TDI Sharan** · 12-12-2007,09:05 PM

Originally Posted by cbrpaul

Engine code and year of your sharan pls ?

Its a 99 on a T plate, where would I find the engine code? The car is new to us so am a bit of a n00b!

**cbrpaul** · 12-12-2007,10:10 PM

probably a AFN same as mine

I have a hot start problem , well did ,

Basically the ECU will not inject fuel into the engine until 250rpm are reached upon cranking,,, this call from the ecu is only when the engine is warmed up !!!

One way to check is to remove the coolent temp sensor connector when hot , as the ECU will default to a cold start map !!

If it starts easily then its this ECU hot start call,

Over the years the starter is not as good , therefore struggles to meet the 250rpm , you can try a new starter , but most are re-con units though , so you could buy a new 1 and it still be present !!

The only other way to cure it is to use vagcom !!

Have you got this or is someone close to you who has it ?

**1.9 TDI Sharan** · 15-12-2007,06:34 PM

cbrpaul, been away for a couple of days...got home to find V5 reg document and yes mine is the AFN engine....hope thats a good one!
Have ordered my dumb lead and have the Vag Com software all ready to go. Funnily enough the wife has said the car has been running fine with no startring issues.....