Help Needed Poor Starting Tdi (110)

[anadin]

:lol: hi, new member probably an old prob 98s tdi 110bhp , difficult starting hot or cold , glow plug light opperates normally , bit like pump timing but car drives great, ticks over sweet, and always starts eventually, only thing ive noticed is the fan runs on after switch off seems faulty ? and if i unscrew the large round wiring plug from right hand side , it starts instantly but all of the dash lights read incorrect , please get me off the annadin any suggestions welcome

[Guest 3.5bullet]

and if i unscrew the large round wiring plug from right hand side , it starts instantly but all of the dash lights read incorrect , please get me off the annadin any suggestions welcome

 

 

Which large round plug? and from where? in the dash or in the engine bay? I would look at the engine temp sensors and go from there? the fans should run on after switching off if the engine is hot? but if they are running even if the engine is cold then that would suggest a temp sensor fault? and possible the causeof the bad starting as the ECU is getting false info on the engines condition!

[anadin]

and if i unscrew the large round wiring plug from right hand side , it starts instantly but all of the dash lights read incorrect , please get me off the annadin any suggestions welcome

 

 

Which large round plug? and from where? in the dash or in the engine bay? I would look at the engine temp sensors and go from there? the fans should run on after switching off if the engine is hot? but if they are running even if the engine is cold then that would suggest a temp sensor fault? and possible the causeof the bad starting as the ECU is getting false info on the engines condition!

[anadin]

hi the round plug is on the right hand side as you look at engine below injector rail, it unscrews, was giving every plug a squirt off wd40, then starting to check any improvment , i thought i'd cracked it when it started instantly but the dash lights went haywire, realising i hadn't re-connected this plug now back to normal frustrating eliminating, yes 1 fan runs permanent and runs on after short runs , so i'm looking here next , many thanks i'll let you know

[anadin]

and if i unscrew the large round wiring plug from right hand side , it starts instantly but all of the dash lights read incorrect , please get me off the annadin any suggestions welcome

 

 

Which large round plug? and from where? in the dash or in the engine bay? I would look at the engine temp sensors and go from there? the fans should run on after switching off if the engine is hot? but if they are running even if the engine is cold then that would suggest a temp sensor fault? and possible the causeof the bad starting as the ECU is getting false info on the engines condition!

changed coolant temp sensor, starting lot better from cold not so good once up to temp, will have to play more

[Scorpiorefugee]

Sorry this is a bit late - been busy.

 

Your problem sounds very familiar and I've had it - took ages and a long story to fix it.

 

The clue is the fan running on.

 

In my case this was due to a faulty coolant temperature sensor. It's in two halves, one is used for the temperature gauge, the other tells the management system what the temperature is and, in my case and possibly yours, this is faulty and, because the engine is reported to be very hot, the fan runs on and the glow plugs are not activated when you start it.

 

The fact that the glow plug light comes on doesn't mean a damned thing unless it stays on for more that a quick flash.

 

How to prove it..... disconnect the sensor.

 

How to find it... mine was in front of the head towards the right hand (gearbox) end and well hidden behind a dirty yellowish filter thingy but there are other variants.

 

Beware! The plug can be a bug..r to get off and the wires have a habit of breaking off, espacially the earth connection.

 

I know that you've already had some of this info but do be careful with the wires and don't forget that you may have one or more faulty glow plug.

 

Hope this helps,

 

Ron.