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.
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.
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.
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.
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.
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.
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.
PYNEY said:
Hi QBee I'm also having the same problem as you in the last couple of months ?
I have a standard 4.5 but the same issue ? car runs fine apart from cold start turns over longer than normal
will be interested to know your findings or I will be calling mat
cheers keith
The car needs to keep pressure in the fuel rail between uses for a quick start up from cold.I have a standard 4.5 but the same issue ? car runs fine apart from cold start turns over longer than normal
will be interested to know your findings or I will be calling mat
cheers keith
I am starting to suspect, following a chat with Jools, that the issue may be one of the components that maintain fuel pressure letting pressure out. The car is going to Mat Smith tomorrow, as I have to go there anyway with my Saab (for a service), so will park the TVR on my trailer tonight and tow it over in the morning, to give him first dibs on tomorrow's cold start
Car spent the day with Mat Smith.
Before I headed for work he plugged his pressure gauge into the fuel rail - I had loaded it onto my trailer last night, and unloaded it this morning without starting the ignition.
No pressure shown, so he disengaged the immobiliser and turned the key.
3.5 bar pressure in the fuel rail the instant the pump started to prime.
So no problem there.
He left it for the morning to see if it decayed over time. Apparently not much.
When I got back this afternoon the car had been on the ramp, boot bung removed, 52mm socket bought, weeping union on the bottom of the tank tightened to solve the leak I had had since the body off refurb over the winter. The starring issue is much more recent, post a battery change.
He then looked again at the starting while his colleague James sat watching the Emerald display on his laptop. Only odd thing they noticed was a momentary voltage drop to 9v on turning the key.
Car fired up almost instantly, as it did when I loaded it back on the trailer at 6.30 to bring it home. So problem apparently fixed.
So we are officially puzzled. I will see what the next few cold starts bring. We cannot see how the weep could be the cause.
Before I headed for work he plugged his pressure gauge into the fuel rail - I had loaded it onto my trailer last night, and unloaded it this morning without starting the ignition.
No pressure shown, so he disengaged the immobiliser and turned the key.
3.5 bar pressure in the fuel rail the instant the pump started to prime.
So no problem there.
He left it for the morning to see if it decayed over time. Apparently not much.
When I got back this afternoon the car had been on the ramp, boot bung removed, 52mm socket bought, weeping union on the bottom of the tank tightened to solve the leak I had had since the body off refurb over the winter. The starring issue is much more recent, post a battery change.
He then looked again at the starting while his colleague James sat watching the Emerald display on his laptop. Only odd thing they noticed was a momentary voltage drop to 9v on turning the key.
Car fired up almost instantly, as it did when I loaded it back on the trailer at 6.30 to bring it home. So problem apparently fixed.
So we are officially puzzled. I will see what the next few cold starts bring. We cannot see how the weep could be the cause.
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