Feb 9, 2016 (3 years ago)
Read this on same subject .
1.7 CDTI Poor hot starting?
I've been having a running battle with my 2007 1.7 CDTI for quite some time now, it runs/starts fine when its Cold but Hunts and takes a bit of starting when its Hot (if its been run for 30mins or more) also it only returns 35mpg if i don't drive it hard.
The problem is i am starting to get the feeling my local Vauxhall dealer doesn't know whats wrong, its been in three times now and every time they run the Tech2 and say there convinced its EGR, Fuel one way valve, Coolant sensor, ECU Map, whilst its been in its also had a New Turbo,Cam belt and full service..... So all those bits have been changed at considerable expense. The Main thing to remember here is that the car does not put the engine light on and there is no stored Fault codes, its done 65,000 miles and has a full VX service History (if thats worth the paper its Printed on).
SO... i drove it again for the first time since getting it back today and its still doing the same thing (no change at all). I'm getting the impression there guessing whats wrong so I've just spent an Hour reading up and even though i was told otherwise i think its a mixture of two faults, i know a little knollage is dangerous but i'm tempted to change the pressure control sensor (the thing i suggested was causing the hunting after reading other similar Threads and got told there was no chance as there was not fault codes) which is is associated with Lumpy idle and hunting which would leave the Hot starting problem.
Now the Hot start problem, Now knowing that the Fault code light isn't coming on i've read would imply the Starter motor would be drawing too many Amps? Which would be about right with how it starts (Cold it starts first revolution with no problem at all, Hot it seems to crank over much more but it's not what you would call slow) so not 100% on the starter and i'm not sure how to check it either.
Then there is the Crank sensor, now this should throw up a fault code but i am reading the symptoms are very similar??
It may well be the disappointment of having spent just over 3k on it since Christmas but do you think these Parts have a decent shot of fixing my problem or am i just throwing more money down the drain?
Bit of an update, I got sick of Vauxhall and took my car to a Local Independent Vauxhall Specialist who fixed it in 2 hours. Turns out i had a bad Fuel Injector (Excessive leak back on no1 causing the Fuel pressure to build slowly) and a dodgy Fuel pump Regulator
Just goes to show Vauxhall Techs are stumped if they cant plug tech2 in and get a fault code to fix.
How it was explained to me was the Injector has to leak X amount of fuel back to the tank to remove any air bubbles from the fuel but at the same time the Injector can't leak back too much fuel or the Pump won