starting problem when hot - 2.0 tdi 16V - BKD engine

[WilliamOctavia]

SKODA OCTAVIA EL 2,0 TDI  16V  BKD   2005   TMBGE61Z552088409 

 

 

Having problems to start when the engine is hot.. cold starts perfect and instantly...

No fault codes on the engine.. cranks 2-4 seconds before start and vibrates heavy.. 

Fuel filter changed and checked for diesel leakage.. 

 

Tried with another charged battery when hot but same problem...

 

Was thinking if it is some of the temp sensors so I did some recording cold vs hot.. 

Could not see any big difference in the values from outsidetemp vs engine temp vs watertemp. 

Hoped that is just some temp sensor but it doesnt seem to be.. have i missed any more temp sensors???

The only big difference in the values from cold to hot is the timing as I could see there. 

 

maybe the starter is so bad and when hot the starting rpm is to low for the ECU to even let fuel in.. 

I read somewhere that some guy changed the map in the ecu for the fuel and that solwed the problem..

[Bazzer1955]

My 1.9 pd is the same and it always starts eventually

[Rustynuts]

Possibly starter motor, battery, camshaft sensor off the top of my head.

[tonyuk74]

Crank shaft sensor could be braking down when hot. Seen this number of times. Not on vag cars tho. A good test is to blow cold air or spay cold water on to the sensor. Only problem with doing that on yours is im sure the sensor is behind the flywheel. You could try to get tdc readings of a good bkd engine and compare yours.

[Anddenton]

Is it possible to log rpm on starting with vcds? might offer some ideas?

[WilliamOctavia]

I have the recordings from another interface not vcds. I will try to get it over on a video.. cold vs hot stats.

[WilliamOctavia]

I found the fault.. 

 

It was a fault in the ECU map. when hot start. the ecu didnt let fuel in under 800rpm.  

 

adjusted the hot start map and flashed the ecu and its normal again! 

[trundlenut]

I found the fault..

It was a fault in the ECU map. when hot start. the ecu didnt let fuel in under 800rpm.

adjusted the hot start map and flashed the ecu and its normal again! [emoji106]

I don't think that's a fault. Normally a poor battery or starter motor means the engine won't crank quick enough for the fuel injection to start. You may have just masked another problem.

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[Golf-Fiend]

Fuel temp sender? Have you changed this? I did recently. Seemed to help a little on hot starts. Quick and easy change.

 

http://www.darksidedevelopments.co.uk/products/1-9-2-0-tdi-pd-fuel-temperature-sensor-sender.html

 

No need to fiddle with the pipes. Just use the sender bit after undoing the clip.

[SuperbTWM]

I found the fault.. 

 

It was a fault in the ECU map. when hot start. the ecu didnt let fuel in under 800rpm.  

 

adjusted the hot start map and flashed the ecu and its normal again! 

Its not a fault in the map, that's how they all are. When warm they don't start injecting till they reach a certain RPM

 

I had the same issue on an '04 1.9PD 105 Golf and had to change the tired starter motor and all was good.

 

Altering the map would of been easier and cheaper though if I could of done it myself  

Edited 19 July, 2016 by SuperbTWM

[Dejan]

i just fixed this issue, dunno if it helps now. well I played a bit with vcds and after changing the value in: Ch01 Engine -> login 12233 -> ch10 adaption -> ch01 changed the value there from 0->100 and no more hot start issues  now for a week with no problems. hope it helps.

yea the right thing to do is to remap the ecu, but I do not have the resources nor $, and I live on the faroe islands where no one does that, so my options were few  but hey, this works

it is a 1.9 tdi bjb Octavia mk2

 

Edited 16 March, 2017 by Dejan