mk 4 golf

**MagicMat** · 20-11-2009,09:02 PM

crasher,

could you please offer some advice ...

... id owe you

**kenney** · 20-11-2009,09:31 PM

Unpluging the temp sensor will not help,the issue,i would suggest replacing the sensor,and see if it helps. Otherwise you will need to read the values of the PD units when the engine is hot.

**MagicMat** · 20-11-2009,09:41 PM

thanks kenny,

i was told un plugging the sensor would make the ecu think the engine was cold and start it quicker...highlighting a problem with the starter motor??

as it turns over with force when its hot?

is there a table of values i can refer to with the VAGCOM unit??

**Crasher** · 20-11-2009,10:21 PM

An AJM does not have an in tank lift pump and tandem pump failure is extremely rare and if it was faulty, would show up from cold. If you have disconnected the coolant temp sender, how the hell was the code read clear? An open circuit coolant temp sender was would have come up at least.

**MagicMat** · 20-11-2009,10:24 PM

hi crasher,

Thanks for putting a post up,

First thing i did was take it to diagnostics, (motortek in doncaster)

It was after that,when i removed the temp sensor.

Do you have any advice?

**Crasher** · 20-11-2009,10:30 PM

The starter is a good possibility but I find they also cause poor cold starting. Analysing the hot cranking speed is quite difficult as you have to get the engine hot, disconnect the injectors (the easiest way to stop it firing up) and then crank it over on a good battery whilst entering the engine diagnostics and keeping it cranking whilst going into measuring blocks to observe the cranking speed, something that takes about 45 seconds of continuous cranking to achieve. I have used the recoding to auto box trick on these as the auto will fire at lower revs and if it starts well, then I change the starter.

**MagicMat** · 20-11-2009,10:34 PM

It may also be worth mentioning,

- I swear it use to be a little dodgy on cold start up a few months back, but it would only happen the odd time,

But two weeks ago i had the head removed (due to a broken glow plug) had the glow plug removed and threads cleaned.

Head then refitted with new head gasket and cam belt.

This was all done by my GF's brother who is an ex audi mechanic who qualfied a couple of years ago (so figured it was safe hands)

It ran alright after the work was done, no hot starting issues. But i swear it still coughed occasionally on cold startup.

--- just read your post cracker

Sounds like cranking speed will be a nightmere to test. Im getting fed up with it all. Think it may be worth just changing the starter motor?

have you found that to be the main cause of the problem?

Matt

**kenney** · 20-11-2009,10:59 PM

You can check the temp sensor it can be checked in measured value blocks group 007.details of the temperature specifications are not possible.When the engine is cold the fuel,intake air and coolant temperatures must equate approximately to ambient temperature.If a temperature deviates noticeably,then the relevant sensor must be checked (replaced)