Cold start issue (for a change!)
Discussion
Thinking caps please, people.
My car has always started on the button, never more than a two second crank and then it fires into life.
I have had a failing Odyssey AGM battery recently, eventually it wouldn't hold any charge at all and, after having had to call Erin Dawes (to whom I am related by marriage) out with the jump leads, I basically stopped driving the car while I sorted it out.
Cut a long story short, new battery in the car after a break of about three weeks. Too busy with work and trying to sort out a warranty replacement.
So I install the new battery within five minutes of its arrival.
Ignition on, fuel pump primes up as normal, big smile on face.
Yes, I can connect a battery correctly first time.
Starter turns over like a whirling dervish with a red hot poker in the right place, so no issues there.
Car takes ages to whimper into life, coughing and spluttering and eventually, with a bit of right foot, it revs and idles happily.
Drives perfectly, and when asked, it restarts perfectly within one second of turning the key.
So I put that slow initial start down to no fuel in the fuel rail and thought no more of it.
BUT, now every time I try to start the car from cold, the fuel pump primes, but the car takes an age (with the starter cranking like a mad thing) to splutter into life. As before, hot starting is absolutely no issue, it runs perfectly, no misfires.
SO, am I looking at an ignition issue or a fuel issue? Any thoughts?
For reference, I am running new coil packs on an Emerald ECU, new Racetech ceramic leads, recently inspected and clean Iridium 6 plugs, new Bosch fuel pump which previously ran fine, in other words I cannot blame parts.
The only thing that has happened since it used to start fine is the dying and then dead battery, and its replacement with an identical but new one. And sitting unused for three weeks, with no battery in the car.
I have not tested anything yet.
My car has always started on the button, never more than a two second crank and then it fires into life.
I have had a failing Odyssey AGM battery recently, eventually it wouldn't hold any charge at all and, after having had to call Erin Dawes (to whom I am related by marriage) out with the jump leads, I basically stopped driving the car while I sorted it out.
Cut a long story short, new battery in the car after a break of about three weeks. Too busy with work and trying to sort out a warranty replacement.
So I install the new battery within five minutes of its arrival.
Ignition on, fuel pump primes up as normal, big smile on face.
Yes, I can connect a battery correctly first time.
Starter turns over like a whirling dervish with a red hot poker in the right place, so no issues there.
Car takes ages to whimper into life, coughing and spluttering and eventually, with a bit of right foot, it revs and idles happily.
Drives perfectly, and when asked, it restarts perfectly within one second of turning the key.
So I put that slow initial start down to no fuel in the fuel rail and thought no more of it.
BUT, now every time I try to start the car from cold, the fuel pump primes, but the car takes an age (with the starter cranking like a mad thing) to splutter into life. As before, hot starting is absolutely no issue, it runs perfectly, no misfires.
SO, am I looking at an ignition issue or a fuel issue? Any thoughts?
For reference, I am running new coil packs on an Emerald ECU, new Racetech ceramic leads, recently inspected and clean Iridium 6 plugs, new Bosch fuel pump which previously ran fine, in other words I cannot blame parts.
The only thing that has happened since it used to start fine is the dying and then dead battery, and its replacement with an identical but new one. And sitting unused for three weeks, with no battery in the car.
I have not tested anything yet.
Not enough enrichment when cold starting.
Is your fuel pressure regulator adjustable by any chance Anthony.
Sounds like it could be low pressure causing lean running which will make it hard to start from cold if my thinking is correct.
Do you have the Bosch stepper motor with that Ecu? Check for air leaks.. odd it's happened since replacing a battery and not before.
As you can probably tell I have no idea so hopefully the more informed will be along shortly.
Is your fuel pressure regulator adjustable by any chance Anthony.
Sounds like it could be low pressure causing lean running which will make it hard to start from cold if my thinking is correct.
Do you have the Bosch stepper motor with that Ecu? Check for air leaks.. odd it's happened since replacing a battery and not before.
As you can probably tell I have no idea so hopefully the more informed will be along shortly.
Thanks guys. You are both saying the same thing.
I agree, it is what it seems like logically, as nothing else points to electrics.
I will plug my lappy into the Emerald and call the Jools, as while I can get the numbers on screen, I don't know wtf it all means.
It may be loads of numbers, but no pound signs, so outside my sphere of operations.
Any more thoughts would be most welcome.
I agree, it is what it seems like logically, as nothing else points to electrics.
I will plug my lappy into the Emerald and call the Jools, as while I can get the numbers on screen, I don't know wtf it all means.
It may be loads of numbers, but no pound signs, so outside my sphere of operations.
Any more thoughts would be most welcome.
May be that your fuel pump isn't priming for long enough. If I leave my car for a long period of time I find it helps if I prime the pump twice, i.e., ignition on and prime/and then the same again.
Obviously the best solution would be to alter the ECU setting but I haven't plucked up courage to alter anything where that is concerned as yet.
Obviously the best solution would be to alter the ECU setting but I haven't plucked up courage to alter anything where that is concerned as yet.
It may be a work around, so thanks for that. I will try it when I leave work this evening.
But I used the car yesterday briefly, then got in to set off to work this morning, and it took an age for the engine to fire.
No, it is happening every time the engine is cold, even if less than 24 hours since the previous use.
But I used the car yesterday briefly, then got in to set off to work this morning, and it took an age for the engine to fire.
No, it is happening every time the engine is cold, even if less than 24 hours since the previous use.
The coolant temp sensor is like an old fashioned choke so if you can get the ECU readings on your laptop, have a look at the temp before you try to start. If it says the engine temp is 80c then that would be the problem. Or if it said -43c that too as then you would be overfuelling. Otherwise as Carsy says a map that needs a tweak so a call to your new friend, Jools.
N7GTX said:
The coolant temp sensor is like an old fashioned choke so if you can get the ECU readings on your laptop, have a look at the temp before you try to start. If it says the engine temp is 80c then that would be the problem. Or if it said -43c that too as then you would be overfuelling. Otherwise as Carsy says a map that needs a tweak so a call to your new friend, Jools.
Good thought. I wonder where the Emerald gets its temperature readings from? It certainly doesn't read the same as my Caerbont gauge on the dashboard. Jools told me that when we were modifying the warm start a few weeks ago.I have actually bought the mod that uses the Range Rover sensor instead of the TVR one, with a variable resistor, for the dash gauge. Seemed like a good idea, and it looks very nice on my desk.
I will check the readings first via my laptop (just need to get an adaptor first, as I bought the wrong cable first time - new one ordered off Ebay), but if they are way out then I will install the desk ornament and see if that improves matters.
If not, then as you say it is time for a call to my good friend Jools.
Engineer1949 said:
just a thought if you have the three position map switch it hasent inadvertently got on to the ridiculously lean mot map by any chance had this before a couple of times
john
Good thought John, but I haven't bothered to have an MOT map.john
My three maps are Road pussycat (2.5 psi), Cadwell Park map (6 psi) and Snetterton map (7.5psi).
All three maps are identical on start up.
The differences are in bhp/torque:
315/395
372/475
395/525
Following the thought above about a double prime, when I had to go out about an hour ago for supplies (working away from home), i tried a double prime on start up. It reduced the turning over by about 85%, so that was a good thought and also backs up the idea that the problem is to do with getting fuel to the injectors. I cannot imagine the mapping on all three maps has changed itself for no reason during three weeks with no running, so am suspecting something physical. It all sounds normal, just doesn't work properly.
I will set either Jools or Mat the Smith onto it.
You don't have an expert or two and bark yourself.
Very odd your calibration has changed after a battery change, I'd go as far to say impossible in fact.
With this in mind and assuming the car started well before the battery change, logic dictates you should start your search not with your unchanged calibration but with the element you have changed.
No, not the battery itself but the security of the terminals you would have removed and reconnected. ECUs are very sensitive to poor earth's so if it was me I'd start my investigations by returning to both live and earth battery terminals to make sure they are 100% tight.
A lose battery terminal (either terminal), even a slightly lose terminal, can cause many confusing issues, solid state memory ECU calibrations don't change with a simple battery swap so focus on what you've changed yourself.
Dave.
With this in mind and assuming the car started well before the battery change, logic dictates you should start your search not with your unchanged calibration but with the element you have changed.
No, not the battery itself but the security of the terminals you would have removed and reconnected. ECUs are very sensitive to poor earth's so if it was me I'd start my investigations by returning to both live and earth battery terminals to make sure they are 100% tight.
A lose battery terminal (either terminal), even a slightly lose terminal, can cause many confusing issues, solid state memory ECU calibrations don't change with a simple battery swap so focus on what you've changed yourself.
Dave.
Thanks Dave - not something I had thought of, given the way the starter cranks like a lunatic now I have the new battery.
I am out working at a client's offices at the moment, but have both the car and the socket set outside the office (it would have been rude not to take the TVR on a nice clear early Sunday morning), and it's coffee break time. I will go have a test of my spannering skills.
I am out working at a client's offices at the moment, but have both the car and the socket set outside the office (it would have been rude not to take the TVR on a nice clear early Sunday morning), and it's coffee break time. I will go have a test of my spannering skills.
If the connections are good I'd start suspecting pump or regulator. Rich had an adjustable regulator, if you feel the back of the regulator it should have an Allen key bolt with a small lock nut around it if it's adjustable. We set that thing time and again then it would lean off on its own accord and cause lean running. Replaced it and it did it again so then replaced it for a set pressure one and it was fine after that. Just undo your petrol cap to discount vacuum Anthony as that could cause this symptom too possibly.
And as your a don with numbers, with a bit of teaching you'd be our master mapper in no time
Numbers is numbers, if you know what to look for spurious numbers will soon show themselves to the trained eye.
If you know a racetrack and have telemetry overlays of your laps, you can soon see where your braking early or not getting on the throttle etc etc, how much brakes you use and for how long, they are very exciting numbers to look at. If your good you can sit at home and follow the lap and know by the graphs curves where you are on the lap.
That doesn't help does it!
Goodluck with it
And as your a don with numbers, with a bit of teaching you'd be our master mapper in no time
Numbers is numbers, if you know what to look for spurious numbers will soon show themselves to the trained eye.
If you know a racetrack and have telemetry overlays of your laps, you can soon see where your braking early or not getting on the throttle etc etc, how much brakes you use and for how long, they are very exciting numbers to look at. If your good you can sit at home and follow the lap and know by the graphs curves where you are on the lap.
That doesn't help does it!
Goodluck with it
Checked the terminals, both as tight as a council's housing budget.
Started the car when I left the client at 9.30 - car was grumpy, despite double priming, but once it was going it was fine and idled perfectly as I hopped out to put the code into the security barrier.
And it then drove fine through pouring rain and spray on the A14 and A11. No complaints there.
I even tried to mop the water off the top of the coil packs yesterday, convinced it was shorting them out.
Took me three dabs with kitchen paper before i finally stuck a finger in the puddle - err, what puddle?
The coil pack upper surface is black and shiny.....Doh!
I am reasonably convinced that this will be fixed by a chat with Jools, so will call him tomorrow.
Started the car when I left the client at 9.30 - car was grumpy, despite double priming, but once it was going it was fine and idled perfectly as I hopped out to put the code into the security barrier.
And it then drove fine through pouring rain and spray on the A14 and A11. No complaints there.
I even tried to mop the water off the top of the coil packs yesterday, convinced it was shorting them out.
Took me three dabs with kitchen paper before i finally stuck a finger in the puddle - err, what puddle?
The coil pack upper surface is black and shiny.....Doh!
I am reasonably convinced that this will be fixed by a chat with Jools, so will call him tomorrow.
^^^^^ 
Even on my very simple engine with Powers own specked cam and with all the years of mapping experience it still took a load of drives to get my mapping right long after it had been rolling roaded and weirdly enough I drove along today thanking Powers for that effort. I was desperate to go to France but Dom kept the car almost two weeks after the Mbe had been installed just running it in different conditions and speeds etc. I'm so glad I let him do that,, I had no choice
but it seems to have been time very well spent.
I think the CUX benifits from deep mapping history and skill and it takes a damn good after market one to match it but when they do with all the other modern benifits of shiny
coil packs etc your onto a winner.
Joolz will sort it in no time
Even on my very simple engine with Powers own specked cam and with all the years of mapping experience it still took a load of drives to get my mapping right long after it had been rolling roaded and weirdly enough I drove along today thanking Powers for that effort. I was desperate to go to France but Dom kept the car almost two weeks after the Mbe had been installed just running it in different conditions and speeds etc. I'm so glad I let him do that,, I had no choice
but it seems to have been time very well spent. I think the CUX benifits from deep mapping history and skill and it takes a damn good after market one to match it but when they do with all the other modern benifits of shiny
coil packs etc your onto a winner. Joolz will sort it in no time
I have been assured that it cannot be the mapping, and I agree.
The car is going to Mat Smith on Wednesday (on my trailer to keep it cold) to see if he can work it out. His telephone diagnosis is that air is getting into the fuel system. Makes sense.
I happen to have a fuel smell in the boot, and if I put my fingers under the tank passenger side they come out smelling of fuel. So Mat will be starting by tightening the tank outlet connections. Luckily mine is a later car with an access bung underneath.
But after that the expert will put his thinking cap on to work out what the issue is.
The car is going to Mat Smith on Wednesday (on my trailer to keep it cold) to see if he can work it out. His telephone diagnosis is that air is getting into the fuel system. Makes sense.
I happen to have a fuel smell in the boot, and if I put my fingers under the tank passenger side they come out smelling of fuel. So Mat will be starting by tightening the tank outlet connections. Luckily mine is a later car with an access bung underneath.
But after that the expert will put his thinking cap on to work out what the issue is.
I think you've found your problem, fuel smell can only mean one thing, leaking, what comes out must go in so you pull over, fuel system leaks out and causing loss of pressure and you are sucking air at the same time as trying to build pressure by turning it over which takes ages.
Pressure test on the fuel rail may say a lot before he tries starting it after first finding any leaks
Pressure test on the fuel rail may say a lot before he tries starting it after first finding any leaks
V8 Junkie said:
Mine is at Lloyd Developments suffering the same problem they have to have it for 5 days to rectify it
Because they have to use it in as many different conditions they can replicate and some. Some of these cars take to a generic map and don't require to much mapping, others take more time to get it right is how I see it.
I'd actually tell them, do it for as long as nesesarry as that's how to get the best maps. It's a lot of work and time consuming so if they can fit it around other things then fair enough as I don't want to have to pay for mapping to often and absolutely not because it's running rough with no obvious reasons like a plug cap off.
The whole idea is you've removed most of the things that cause issues,,, the map shouldn't now be one of them.
I'm sure it will be perfect when you do get it back.
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