Cold start issues

[Dogbreath]

Anyway, it came up with an error code of "P0150" which on this car is a malfunctioning oxygen sensor circuit, which can also cause rough starting.

The oxygen sensor is so unlikely to cause problems with starting that you can pretty much forget it. This sensor isn't even used by the ECU until the engine is warmed up.

OTOH, the coolant temperature sensor will cause starting problems if it is reporting the wrong engine temperature.

 

[Amp34]

Interesting. I think the coolant sensor is also on the same circuit. I know from aforementioned previous conversation with the owner that the issue was intermittent, and it appears to have gone again, which I guess is why the mechanic couldn't sort it. It could well be a related to a dodgy connection somewhere. I'll be keeping an eye on it and next time I get to the garage will get them to check it out. It starts up fine again now...

 

[Amp34]

So just started the truck up this afternoon and the got the same rough start. The first time since I started the thread in May (and ~5,000 miles).

Interestingly it's the same scenario as last time, not much fuel left in the tank and then fill up to the brim, then the next cold start (filled up yesterday) it starts rough. That said looking at past refill history the fuel left wasn't significantly lower than a few other times I've refuelled.

To me that does seem to imply it's some form of fuel issue. I'm wondering if perhaps there's some gunk in the tank, or if the fuel filter may need changing?

EDIT: Searching online it looks like it could be a dodgy Canister Purge Valve, which is supposed to equalise the pressure in the fuel tank. It appears to also be connected in some way to the O2 sensor system, so those errors can come up. Anyone else has this issue with a vehicle? I'm assuming on mine it's more an intermittent issue, as it appears to work most of the time, but occasionally get dodgy, like now.