How does ECU control the ignition?
 

i'm messed about this topic.. i know that the ignition is controlled through distributor and too the cam gears, right? then , how does the ecu control the ignition? (i just learning the fuel and ignition maps :-[)

Re: How does ECU control the ignition?
 

It uses electrons.

Re: How does ECU control the ignition?
 

Notices all the wires comin out of the dist. they go to the ecu

Re: How does ECU control the ignition?
 

ECU = Engine Control Module

Re: How does ECU control the ignition?
 

Ever notice that the rotor in the dizzy has a long trailing contact edge? This is to account for the varying ignition trigger points controlled by the ECU. The dizzy is just a mechanical means of directing the spark to the appropriate cylinder when its firing order comes up. The ECU determines the exact crank degree for firing.
Also, the reason why you can unbolt and adjust the dizzy is because the sensors that the ECU uses to determine the crankshaft position is located inside the distributor; which allows you to sync the physical sensor pickup with the ECU.

HTH,
Dave

Re: How does ECU control the ignition?
 

so, though the long trailing is contacting with edge , could b that there be not spark until the ECU decide if there are spark or not, right ?

Re: How does ECU control the ignition?
 

Lets play a game



Go unplug the big plug on the dist that goes to the ecu



Now go see if you have spark

Re: How does ECU control the ignition?
 

what plug do you refer?

http://www.hivolume.com/images/351/YMHD041.jpg

that with a lot of wires ? :-[

Re: How does ECU control the ignition?
 

yes

Re: How does ECU control the ignition?
 

mm i see, so ,trhough this plug , pass the spark to a determinate time (advance or retard timing), right? but i have seen that you can to move the distributor for advance or retard the timing... i think this topic about distributor,spark,etc is very difficult to understand :-[

Re: How does ECU control the ignition?
 

Not really.

Re: How does ECU control the ignition?
 

teach me then ;D , so, there are two way for to advance or retard timing? one way is to move the distributor, (right or left) , and the other way is about to do it through ECU?.. :6

Re: How does ECU control the ignition?
 

Yes. Moving your distributor will change your timing a set amount (a degree or a few degrees depending on how much you move it) and that translation will be applied for ALL rpm values.

Most people who change timing through the ecu, are changing specific values associated to RPM/Map value. Instead of retarding your timing by 5 degrees across your WHOLE map by moving your distributor, you can retard/advance the timing the exact amount you want in the exact place when you change the ignition map on the ecu.

Re: How does ECU control the ignition?
 

ok i understand.. :D can i do other question about ignition? :-[ , it's about ignition map. :-[

Re: How does ECU control the ignition?
 

I guess

Re: How does ECU control the ignition?
 

:D ok , i dont understand about timing belt for example in uberdata, the ignition map, ok, those values are the degrees, right? ok, in BTDC ? that i dont understad.. i know what its BTDC (when piston is botton..).. i can imagine myself that, who it's work.. :-[

thank you for your patience :-[

Re: How does ECU control the ignition?
 

What is your question? What about the timing belt? BTDC=before top dead center.

Re: How does ECU control the ignition?
 

mm i dont understand the values mean of ignition in BTDC... :l ... but i think that you dont undestand to me so, leave it ;D

Re: How does ECU control the ignition?
 

The values are degrees of advanced igniting before top dead center. You can also set values of timing based on boost (the top row in most editors). The more boost, the less advancement of timing you will have (retarding the ignition). The values themselves may not tell someone a whole lot just by themselves, but relative to the other values in the map you can at least see the pattern.

Re: How does ECU control the ignition?
 

Sad thing is, I think I'm the only one in this thread who understands how the ECU uses each individual distributor sensor, how exactly the ignitor is fired by the ECU, and the exact nature of the tach signal. Well, one of the Chris's might. Not that it matters... because... it's all written in a Helms manual, anyway. There's something to be said for reading the factory service literature a time or two.

:-\

Re: How does ECU control the ignition?
 

wow , josep davids (later i did know who you are but now yes). i think too, i will try to understand it. :y

Re: How does ECU control the ignition?
 

I have no idea what you just said, but I like it!

Re: How does ECU control the ignition?
 

i said that i can no to explain better for you understand what i need to learn, and i will try to learn reading (or try cuz my bad english) tech articles as the wiki of PGMIF.org or so.

Re: How does ECU control the ignition?
 

Yup, it's all there. Helms is actually pretty good at explaining what each sensor does.

Ok smarty pants, how exactly does the ecu communicate with the 7U016 to produce the ignition signal. ;)

Also one thing I speculate on is that the ecu does nothing to control the actual timing sequence. If you notice the signals coming from the distributor sensors all go into the 7U016. So that makes me think that those pulses act like a clock signals and the ecu simply applies an offset so to speak that provides the ignition value. It applies to the fuel injectors firing too, but since there is an individual cylinder correction, then the ecu doesn't apply a bulk value, but instead knows which injector is firing and thus adjusts it accordingly.

Re: How does ECU control the ignition?
 

oh, good explain, what is 7U016?

this case is the same in B16a ,right? i means that the ecu (or 7U016), control the ignition..