Delayed Starting

[the nogmiester]

Hi.I recently bought a MK1 Sharan 1.9 tdi and have a starting problem.First start in mornings take about 3 goes but once she starts she runs perfect and drives well.Once she`s warm she takes about 10 secs to start.I`ve changed the fuel filter and valve, glow plugs and the coolant sensor test fine.Now, at some stage in the past, a previous owner as by passed the glow plug relay and installed a push button on the steering column to operate the glow plugs manually. which works fine.I can`t help thinking this is confusing the ECU and thus delaying starting.Why would someone by pass the relay? Also on cold morning 1st start, I eventually get some smoke just before firing up ! Help me please before I have to spend a fortune at VW.

[nicebutdim]

A good start to diagnosing problems is to get a haynes manual, the ford galaxy one is same as sharan, and get a vagcom cable from ebay, they're cheap and allow you to check tons of stuff within the engine and electrics. Just for the engineers to drive it in through the doors of the garage will cost more than both the above items!

[JONESERIC]

Hi I had a similar issue with my Galaxy. It turned out to be a faulty relay. However, concerning the ECU. The ECU monitors the engine temp and applies power to the glow plugs if required on engine start, it is not as simple just applying power at Start, the ECU also commands power to the glow plugs when the engine is cold to enable smooth running, it is this interdependency between the ECU / Glow plugs and engine temperature that is crucial at start-up. Therefore to summarize it is probable that delayed starting could be caused by the "hot wiring" of the glow-plug system.

 

Rgds

 

Eric