recently, have been noticing that on a cold start, car will crank for a long time before the engine actually fires up. this only happens on a cold start.

when the car is warmed up, it fires right up.

any idea what this might be? car is an 06 v8 vantage

 

Might have been a total coincidence, but I had a similar issue right before needing to replace an o2 sensor.. After replacing it, starting went back to normal.

 

I had this on a Merc 600 and when they found out why it turned out to be the oil pump? it seems that the ignition firing cct was only activated once a certain oil pressure was reached?
In this car's case it used to stand (like my Vantage does) for days without starting and what they (the benz dealer) says is that the oil needs to pump up the valve hydraulic drive?

However in reporting this to you guys I have merc 350 that sometimes stands and when started from cold one can hear the noisy valve lifters getting pressure before becoming silent, yet this one fires up immediatley? when I approach the benz dealer everyone is silent on how one fires and one does not.

Looking fwd to getting Irish's comments on this one

 

Mine (07 vantage) has a start procedure for after it has been stored, holding accelerator to floor while cranking engine. Car will not fire put oil pump works and when oil light goes out you start. This being the case, I would be surprised if there were a pressure sensor involved in the start procedure of the car normally.

 

This procedure for the throttle is to cut off the fuel....over a long period u can loose fuel pressure and leak air into the fuel rail. By holding the throttle to the floor while cranking will cut the fuel to dry out the plugs and get a vacuum going in the fuel rail, now while still cranking release the throttle and the engine will fire up..this procedure can also be used if it engine is possibly flooded

 

On a cold start only cranking is longer...not many causes for this..haven't seen any issues and I live in an igloo in the winter months..

Have u checked the battery to make sure correct CCA is achieved..also have u scanned for fault codes?

I've seen this on V12's with fouled spark plugs, how much mileage do u have in the car?

 

havent scanned for any fault codes. car has 18k miles.

 

Resurrecting this thread as my car has gone from firing right up to abnormally long turning over prior to starting in a matter of a couple weeks. Initially it would take about three beats and then fire up. Now more than double or triple that although it’s started each time.

I’ve had it on a battery tender so I don’t think the battery. And it is only on a cold start - If I drive 30 minutes- turn off and turn right back on it’s fine.

I think it’s an issue with the fuel rail holding pressure over a day- but looking to see other people’s experience. Including:

what cost am I looking at to fix- I’m honestly more worried about lead time for the parts…has anyone had experience getting this fixed?

I worry a little bit about additional stress on the battery and starter but this isn’t a big deal if it won’t result in me eventually getting stranded - so has anyone had this issue and then developed to the point it wouldn’t start?

car is an 08 vantage roadster with 30k miles

thanks!!

 

the programming in the ECU is so complicated WRT when it will send a spark that's it's unlikely that anyone has a realistic idea of all the contingencies and dependencies that may cause hard starting. the software engineers have painted themselves into a corner on this one AFAIK.

 

Seems like the fuel rail has lost pressure and is slow to re-pressurize. Not sure about the 2007 vantage , but most current vehicles pressurize the fuel rail before the starting sequence. My Porsche Macan starts the fuel pump to pressurize the fuel rail when the drivers door is opened and the cars senses the key fob.

 

yup I do and that’s my next stop as well as a dealer as I’m in the LA area. But was hoping to see if anyone had it before to let me know if this is a TODAY problem or when I get around to it problem.

 

My v8v recently started firing up slower. Did you find out what the cause was?

 

my first guess would be a faulty temp sensor.

the good news is that they are very inexpensive to purchase. the bad news is that the intake manifold needs to be removed to get at it.