Discussion
need a little help guy's, for some reason my 400 (flapper AFM) does not like starting from cold!
The only way i can get it to start is to turn the dizzy anti clockwise about 20 BTDC degrees and then she burst into life and will sit ticking over at about 1500rpm until she warms up then after a blip on the throttle will back of to around 1200rpm, the problem is once warm does not like running with dizzy in this position, jerky at low speed and pinks around 4000rpm!! i can turn the dizzy back to where it should be which is around 8-10 degrees BTDC and she runs like a dream, no pinking, smooth at low speed. once warm she will start with a little prod of the throttle but as soon as she's cooled down does not want to start without turning dizzy again!!
The cold start injector is currently disconnected and as i understand this is normal, when i have started the car from cold and checked voltage on plug there's no voltage there anyway!
The dizzy is fairly new and as far as i can tell seems in good working order (although cheaper ebay job not lucas), rotor arm will move approx 20 degrees clockwise when twisted. new coil, magnacor leads, lucas arm and cap.
I've used a timing light, disconnected vacuum pipe and blanked off at plenum end, at idle is 8-10 degrees BTDC and moves to around 25-30 degrees BTDC at 3000-4000rpm.
i'm running out of ideas now and not sure wether i totally understand how it all works or if i'm making things worse, so please feel free to tell me that i'm an idiot and i've got it all wrong!!!!
The only way i can get it to start is to turn the dizzy anti clockwise about 20 BTDC degrees and then she burst into life and will sit ticking over at about 1500rpm until she warms up then after a blip on the throttle will back of to around 1200rpm, the problem is once warm does not like running with dizzy in this position, jerky at low speed and pinks around 4000rpm!! i can turn the dizzy back to where it should be which is around 8-10 degrees BTDC and she runs like a dream, no pinking, smooth at low speed. once warm she will start with a little prod of the throttle but as soon as she's cooled down does not want to start without turning dizzy again!!
The cold start injector is currently disconnected and as i understand this is normal, when i have started the car from cold and checked voltage on plug there's no voltage there anyway!
The dizzy is fairly new and as far as i can tell seems in good working order (although cheaper ebay job not lucas), rotor arm will move approx 20 degrees clockwise when twisted. new coil, magnacor leads, lucas arm and cap.
I've used a timing light, disconnected vacuum pipe and blanked off at plenum end, at idle is 8-10 degrees BTDC and moves to around 25-30 degrees BTDC at 3000-4000rpm.
i'm running out of ideas now and not sure wether i totally understand how it all works or if i'm making things worse, so please feel free to tell me that i'm an idiot and i've got it all wrong!!!!
There is no valve in my 350i.
I have found that when starting my 350i from cold after it has stood a for a few weeks, it starts much easier/quicker if I hold the throttle open a touch.
Not really sure why, and it's against the recommendation in the manual but definitely works for me.
I did think that maybe the flapper on the AFM was getting stuck through lack of use, and opening the throttle forced enough extra air through to free it.
I have found that when starting my 350i from cold after it has stood a for a few weeks, it starts much easier/quicker if I hold the throttle open a touch.
Not really sure why, and it's against the recommendation in the manual but definitely works for me.
I did think that maybe the flapper on the AFM was getting stuck through lack of use, and opening the throttle forced enough extra air through to free it.
had exactly the same on my first 350 in the fact it was the wrong way round, i think the idea is that it stops the vacuum shutting too quickly when backing off the throttle, when coming to a stop they hold the advance/revs a few 100 rpms higher and then after a minute slowly drop the advance back.
what i'm not entirely sure on, is the vacuum advance meant to work with the throttle closed or open, my brain is telling me closed as once the throttle butterfly is open there can't be a vacuum but then doesn't that contradict my last paragraph!!!!
what i'm not entirely sure on, is the vacuum advance meant to work with the throttle closed or open, my brain is telling me closed as once the throttle butterfly is open there can't be a vacuum but then doesn't that contradict my last paragraph!!!!
In the words of our Lord Joolz Lane, TVRCC mailing list, August 26th 2001:
"The valve thingy is just a restrictor that works better one way than the other... it restricts the vacuum communicated to the advance mechanism when on cruise conditions so it will suck advance on, but only after a few seconds of holding at light throttle. This prevents advance coming on when you go through the cruise portion of throttle towards high throttle. When you lift off the throttle, any vacuum that has been communicated to the advance unit releases quickly... the intention is not to add vac advance unless the car is definitely in a cruise state, thus limiting the chance of pinking under transient throttle conditions. If you install the unit the wrong way round you will run with ten degrees of extra advance all the time."
So the vac restrictor shouldn't affect starting unless it's been fitted backwards...
"The valve thingy is just a restrictor that works better one way than the other... it restricts the vacuum communicated to the advance mechanism when on cruise conditions so it will suck advance on, but only after a few seconds of holding at light throttle. This prevents advance coming on when you go through the cruise portion of throttle towards high throttle. When you lift off the throttle, any vacuum that has been communicated to the advance unit releases quickly... the intention is not to add vac advance unless the car is definitely in a cruise state, thus limiting the chance of pinking under transient throttle conditions. If you install the unit the wrong way round you will run with ten degrees of extra advance all the time."
So the vac restrictor shouldn't affect starting unless it's been fitted backwards...
possible break through today!!! pulled off the hose that goes from the extra air valve and into the back of plenum and ................she fired almost straight away...........ok she didn't like running with pipe off so i pushed it back on but loosely fitted and she started fine!
so my conclusion is: there's a lack of air on cold starting, i've removed the extra air valve and when cold its shut so will replace it. Is there anything else i should be looking at that could starve the engine of air when starting from cold?
so my conclusion is: there's a lack of air on cold starting, i've removed the extra air valve and when cold its shut so will replace it. Is there anything else i should be looking at that could starve the engine of air when starting from cold?
hallsie said:
Hey, do you know my wife???? 
Actually, she is happy with me keeping all the spares and rnandom bits as long as I sell the silver one to pay for the kitchen!!
Stu
Blimey Stu!Actually, she is happy with me keeping all the spares and rnandom bits as long as I sell the silver one to pay for the kitchen!!
Stu
A kitchen for a couple of hundred quid
Oh go on! I'll up it to 500 squid for the "silver one" just to help you out and keep the marital bliss at home
MarkS1966 said:
hallsie said:
Hey, do you know my wife????
Actually, she is happy with me keeping all the spares and rnandom bits as long as I sell the silver one to pay for the kitchen!!
Stu
Blimey Stu!Actually, she is happy with me keeping all the spares and rnandom bits as long as I sell the silver one to pay for the kitchen!!
Stu
A kitchen for a couple of hundred quid
Oh go on! I'll up it to 500 squid for the "silver one" just to help you out and keep the marital bliss at home
Stu
mrzigazaga said:
3 kwid..Thats way too cheap mate!..I'll give you 200 ugandan dollars..An elephant leg and a cushion filled with quails feathers... 
Damn Zig!You beat me too it and your bid is waaaaaay too high, I couldn't afford the elephant leg, was going to suggest a hippo, but can't run to a whole elephant leg, let alone adding in a bag of quail feathers! You super rich show off gits are all the same
Is that impending inheritance of yours coming from your Nigerian aunt
if so, it may take a while to come though!I'm still waiting for the cash from that lovely banker who was in a bit of trouble with a deceased persons estate and just needed someone's account details to transfer the money into
Seriously though Stu, she's lovely and I'll PM you ref the 3Kwid!
MarkS1966 said:
hallsie said:
Hey, do you know my wife????
Actually, she is happy with me keeping all the spares and rnandom bits as long as I sell the silver one to pay for the kitchen!!
Stu
Blimey Stu!Actually, she is happy with me keeping all the spares and rnandom bits as long as I sell the silver one to pay for the kitchen!!
Stu
A kitchen for a couple of hundred quid
Oh go on! I'll up it to 500 squid for the "silver one" just to help you out and keep the marital bliss at home
Stu
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