when does the Distributor, produce signal (for rpm) ??

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Re: when does the Distributor, produce signal (for rpm) ??

Postby kwempe » Wed Jan 22, 2014 9:27 pm

Certain non sequetional fuel injection systems could run without a tdc sensor, thats why I want to see what you want to fit?

If you wonder why you can't calculate where the engines cycle is think of it this way, the distributor spins at half the rpm of the engine so the engine will make two complete revolutions for every one that the distributor does. The engine then reaches TDC twice for every rotation of the distributer, how can the distributer "know" which one of the times it reaches tdc it is about to be on an induction stroke or on an exhaust stroke? And if you have four cylinders how can it know which cylinder is at tdc? Have a look at the "chopper" under your rotor arm, if all the chops are the same then it has no form of TDC sensor, if one is a differant size then you could well have a crude form of tdc sensor right there.....
Very early injection systems dont care by the way, they just squirt all four injectors at the same time but you only have to move forward very slightly before the sytem will at least require a TDC sensor of some sort.....

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Re: when does the Distributor, produce signal (for rpm) ??

Postby settra » Wed Jan 22, 2014 9:36 pm

my car is Carbiratur. it is the B4 1992, 1.6lt. all the models after 1993 had multi point injection.
(i also dont know of the exact things, that the injection system will have...)

i dont know of the distributers, inside, BUT the car has an Motronic 1.2 ECU mounted under the dashboard... probably used to control the ignition timing...

if i measure the pulses, that the distributor gives (it has a plug with only 3 wires as i seD), they give MAX 8000rpm??? so what, the car can get to 16000rpm??? (by the way, i do not have a speedometer atm)

so lets look it this way :

if i have a cam sensor, like the ones u posted, and i use it to know when the cam is at "X" BTDC. then, if i know the speed of the cam (by the same sensor), and since the cam opens all the valves, in each rotation, then , i can use that info, to do sequintal injection, right??
i have search allot after your posts, and i have come to believe that the additional crank sensor is for very High End proposes, and not a necessity , for basic to advanced EFI??

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Re: when does the Distributor, produce signal (for rpm) ??

Postby settra » Wed Jan 22, 2014 10:04 pm

by the way, bear in mind, that the whole project is not so much "i want to conver to injection"
but more like , " i want to create an EFI ECU" ;) more like a hobby think... so, i dont care to do anything sophisticated, ISO aproved, an crap like that :P

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Re: when does the Distributor, produce signal (for rpm) ??

Postby kwempe » Wed Jan 22, 2014 10:12 pm

Does this help? You need to check but you probably have speed and position sensors fitted, check the bell housing for a plug or just about an inch or two from the flywheel end of the engine.
You might be able to fit all the parts like for like from a donor car?

http://forums.bimmerforums.com/forum/showthread.php?1562989-Motronic-1-2-and-1-3-explained

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Re: when does the Distributor, produce signal (for rpm) ??

Postby kwempe » Wed Jan 22, 2014 10:17 pm

You will get two pulses for every rotation of the engine on a distributor by the way so if you run your engine at 2000 rpm you would get 4000 pulses per minute. If it is a true engine speed signal you are measuring then you could get lots more than that.....

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Re: when does the Distributor, produce signal (for rpm) ??

Postby settra » Wed Jan 22, 2014 10:35 pm

yiap. there is a sensor there, which i never managed to read, but i though it was the VSS???
well, that is the reading i get from the distributor... BUT when i am in idle, the pulses are 1000per minute... so , i thought it was pretty accurate???... i am starting to thing my car, runs some pretty weird shi :angel: t :D

but you didn't answered me... will a cam sensor be enough for injection??

(as for cam position,even if the car had a cam sensor, i would prefer an optical DIY , since the signal will be much better, for basic AVR's )

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Re: when does the Distributor, produce signal (for rpm) ??

Postby kwempe » Wed Jan 22, 2014 11:01 pm

If it has a flywheel sensor there is probably a single larger gap in a segmented disc to tell the ecu where TDC on number 1 cylinder is, if not you probably already have a cam sensor too......Can you measure any signal from the flywheel sensor? if it is only an engine speed pulse then it might be just a pin on 5th eflywheel rather than a segmented disc.......

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Re: when does the Distributor, produce signal (for rpm) ??

Postby settra » Wed Jan 22, 2014 11:24 pm

i will try, but mesuring it, will take some time.... but i am prety sure that it is a the VSS, cause there is got to be one, and where else can it be???

all the above u sed, could be in the distributor??

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Re: when does the Distributor, produce signal (for rpm) ??

Postby kwempe » Wed Jan 22, 2014 11:27 pm

has your car got abs brakes? If it has then it wont have a vehicle speed sensor and in any case if it has a VSS then it will be on the gearbox, near the differential, not on the bell housing or engine..... :thumbup:

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Re: when does the Distributor, produce signal (for rpm) ??

Postby settra » Wed Jan 22, 2014 11:34 pm

ok cool. i will look it up!! in the meantime, do you think that cam position, would be enough, for the fuel injection??

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