Cerbera will not start once warm
Discussion
Tylersloca said:
The car starts right up and runs awesome but once it is warm it will not restart. Car cranks over just fine but wont fire up. Once it cools down it will fire right up again.
Are the fuel hoses heat wrapped? Could be fuel vapourisation. I had a similar problem with an old 4.2, does point that way if the car is cranking nicely. I vote battery.
I had this on the Griff and spent lots of time chasing fuel vaporisation as that is what I thought it was, but whatever I did, it made no difference.
One day the battery died, and with a new battery, the hot start problem vanished. On the Griff, the starter motor is very close to the exhaust manifold and I think it must have been getting hot. Whilst it appeared to be cranking over quickly on the old battery, with the new battery the problem simply disappeared.
I had this on the Griff and spent lots of time chasing fuel vaporisation as that is what I thought it was, but whatever I did, it made no difference.
One day the battery died, and with a new battery, the hot start problem vanished. On the Griff, the starter motor is very close to the exhaust manifold and I think it must have been getting hot. Whilst it appeared to be cranking over quickly on the old battery, with the new battery the problem simply disappeared.
I had similar a couple of years ago with my Cayenne. Where is the starter motor located in a Cerbera? In my Cayenne it is located where it can get quite hot. Consequently, the first start of the day was trouble-free. Starting again after, say, a drive to a petrol station was a bit embarrassing because it would need several attempts. It wasn't the number of attempts that achieved the restart but the cooling-down time during the process. I now have a new starter motor and have refound my confidence at fuel stations . . .
Why are people suggesting it is the battery if the car is cranking over fine?
I would echo the diagnostics. If the car is not starting when warm its because the warmth has changed something
So either the car doesn't know its warm and is using the wrong point of the ignition and fuel map to start, hence checking the sender using the diagnostics
Or warmth has expanded the metalwork in some defect to cause air entry past the butterflies and a mixture too weak to start.
I think I would go there rather than looking at the battery currently
I would echo the diagnostics. If the car is not starting when warm its because the warmth has changed something
So either the car doesn't know its warm and is using the wrong point of the ignition and fuel map to start, hence checking the sender using the diagnostics
Or warmth has expanded the metalwork in some defect to cause air entry past the butterflies and a mixture too weak to start.
I think I would go there rather than looking at the battery currently
I suggested the battery, because that was my experience.
Not the case here as the OP has confirmed he has a new battery.
In a previous post, the point is made that when the starter motor gets hot it struggles, albeit fine when cold.
I spent ages chasing my "hot start" issue. It turned over nice and fast even when hot. BUT, the day I changed the battery, the hot start issue just disappeared. "Evaporated" if you will excuse the pun.
I have to apologise, in that I said it was in my Griff, but actually it was before that in the 350i, but on both the starter motor is only a rizzla thickness from the exhaust manifold.
Not the case here as the OP has confirmed he has a new battery.
In a previous post, the point is made that when the starter motor gets hot it struggles, albeit fine when cold.
I spent ages chasing my "hot start" issue. It turned over nice and fast even when hot. BUT, the day I changed the battery, the hot start issue just disappeared. "Evaporated" if you will excuse the pun.
I have to apologise, in that I said it was in my Griff, but actually it was before that in the 350i, but on both the starter motor is only a rizzla thickness from the exhaust manifold.
julian64 said:
Why are people suggesting it is the battery if the car is cranking over fine?
I would echo the diagnostics. If the car is not starting when warm its because the warmth has changed something
Agreed, in this case unlikely to be battery relatedI would echo the diagnostics. If the car is not starting when warm its because the warmth has changed something
However it is worth mentioning that it is perfectly possible for the engine to crank and the engine fail to fire due to the battery condition
I'm guessing this is because the battery voltage drops to a level where the injectors fail to open
ukkid35 said:
julian64 said:
Why are people suggesting it is the battery if the car is cranking over fine?
I would echo the diagnostics. If the car is not starting when warm its because the warmth has changed something
Agreed, in this case unlikely to be battery relatedI would echo the diagnostics. If the car is not starting when warm its because the warmth has changed something
However it is worth mentioning that it is perfectly possible for the engine to crank and the engine fail to fire due to the battery condition
I'm guessing this is because the battery voltage drops to a level where the injectors fail to open
The injectors only need milliamps. What's the chances that the battery has enough current to make a starter motor turn swiftly but not the extra to run the injectors
Possibly if the battery is having trouble turning over the car as the voltage may have dropped so low that the electronics aren't functional, but that is not a car that is cranking fine?
If cranking normally, yes the battery would not be considered the issue. However, my experience with a Cerbera AJP from 2018-19 was that what would be a normal cranking / starting speed for another car was insufficient for the Cerbera. 
For example, just a slow turn over is enough for my current RV8 Griff to start OK. On the Cerbera, it would have to turn at high speed with a fully charged battery for it to start.
For example, just a slow turn over is enough for my current RV8 Griff to start OK. On the Cerbera, it would have to turn at high speed with a fully charged battery for it to start.
sixor8 said:
If cranking normally, yes the battery would not be considered the issue. However, my experience with a Cerbera AJP from 2018-19 was that what would be a normal cranking / starting speed for another car was insufficient for the Cerbera.
For example, just a slow turn over is enough for my current RV8 Griff to start OK. On the Cerbera, it would have to turn at high speed with a fully charged battery for it to start.
This is one of the advantages of a lithium (LiFePO4) battery, eg from deadweight (thanks to JHonno for that recommendation). According to the app which connects to the battery monitor, mine cranks at 15 compression pulses/sec (900 compressions/min = 225 rpm) and the minimum voltage during cranking is around 11.7 volts. The 11Kg weight saving is a nice side-effect.For example, just a slow turn over is enough for my current RV8 Griff to start OK. On the Cerbera, it would have to turn at high speed with a fully charged battery for it to start.
Do not take the rubbish above advice about the lithium ion battery. It is a £300 camper van battery. Great for running the TV or fridge. It is not suitable for starting a TVR. That is why car manufacturers don’t fit them for that purpose.
Just Google it. You will see the batteries plus.com blog, where it categorically states that they are not suitable for starting a car.
Just Google it. You will see the batteries plus.com blog, where it categorically states that they are not suitable for starting a car.
LucyP said:
Do not take the rubbish above advice about the lithium ion battery. It is a £300 camper van battery. Great for running the TV or fridge. It is not suitable for starting a TVR. That is why car manufacturers don’t fit them for that purpose.
Just Google it. You will see the batteries plus.com blog, where it categorically states that they are not suitable for starting a car.
Just Google it. You will see the batteries plus.com blog, where it categorically states that they are not suitable for starting a car.
I couldn't give a flying f
k what you Googled.Edited by FarmyardPants on Sunday 1st October 17:41
FarmyardPants said:
LucyP said:
Do not take the rubbish above advice about the lithium ion battery. It is a £300 camper van battery. Great for running the TV or fridge. It is not suitable for starting a TVR. That is why car manufacturers don’t fit them for that purpose.
Just Google it. You will see the batteries plus.com blog, where it categorically states that they are not suitable for starting a car.
Just Google it. You will see the batteries plus.com blog, where it categorically states that they are not suitable for starting a car.
I couldn't give a flying f
k what you Googled.Edited by FarmyardPants on Sunday 1st October 17:41
Sorry if I missed it, but what engine?
My old 4.2 would stall when really hot (thought would start up fine) which I put down to vaporisation. Solved when I decatted it.
But like I mentioned, not issues starting up when hot. So might not be that. Esp if decatted and/or its not a 4.2.. The 4.5 doesn't suffer from the issue at all.
Oh, and the 4.2 would crank really slowly too, it'd chug away but start up just fine. I replaced the battery with a standard exxide and it wurred away much quicker, and just gave a lot more confidence that it wasnt going to go flat if it did fail to start on the first crank. Lol
My old 4.2 would stall when really hot (thought would start up fine) which I put down to vaporisation. Solved when I decatted it.
But like I mentioned, not issues starting up when hot. So might not be that. Esp if decatted and/or its not a 4.2.. The 4.5 doesn't suffer from the issue at all.
Oh, and the 4.2 would crank really slowly too, it'd chug away but start up just fine. I replaced the battery with a standard exxide and it wurred away much quicker, and just gave a lot more confidence that it wasnt going to go flat if it did fail to start on the first crank. Lol
Edited by Billy_Rosewood on Monday 2nd October 09:49
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