AccordTech 101: Distributors

[ACCLUDE]

Due to a question brought up in another thread I figured it would be nice to have a thread covering this.

Reply if you know, look it up if you don't.

1. Where is the distributor located and what does it do?

2. On our Accords (and all cars with distributors) the distributor coil is either external or internal. What is the difference between the two besides the obvious. Is one better than the other?

BONUS: How do you test for a bad coil? (what is the correct resistance range the coil should read)

[91SEeinblue]

1. On the F22 series the distributor is located on the left end of the "valve cover assembly." It's actually attached to the cam. IT's function is time the spark "distribution" with the engine sequence (right before TDC during compression, at TDC..so on so forth).

2. Sorry guys, i have no clue about this one. haha. The manual doesn't even say anything about the benefits of one over the other.

3. Now im looking in the 5th Gen Service Manual for all of this here, but on the 5th gens, the range for resistance for the primary winding is .45-.55 ohms on the F22B1 and on the F22B2 its .64-.78. Secondary winding is 16.8-25.2 k ohms on the F22B1, F22B2 is 14.4-21.6 k ohms.

Process: F22B1- Remove distrib cap. Remove 2 screws to disconnect 2 wires (blk/yel and wht/blk) from terminals A (+) and B(-). Use Ohm meter to measure resistance between terminals A and B. IF not within specs, replace.

F22B2-Pull off 4P connector. Measure resistance between all terminals. IF not within specs, replace coil.

[ACCLUDE]

Awesome!

#1 you got without a problem

#2 still needs to be answered, so anybody?? Try looking in other places that have general coil information instead of honda manuals cuase it won't be in there. This is more of a general question and not Accord specific.

#3 is close enough. Good job on those specs. The F22's in our 4th gens have a coil resistance that is closer to the F22B2 specs you put up (about 14,000-22,000 ohms). The internal coil on the 90-91 Accords can actually be used as a cheap alternative on the H22 distributor instead of having to buy the H22 specific coil which is damn near impossible to find. The internal coil H22A/H22A1 and F22A1,4,6 coils are all the same.


NEW QUESTIONS!!!

4. What does TDC/CKP/CYP stand for? What purpose do they serve?

BONUS:
List the ECU pinout locations of all the distributor wires that go to the ECU and what they are. For example, list them as - "Pin A1, Brown, Fuel injector #1" (not distributor related but you get the idea)

[92BLACKEX]

Well TDC stands for my initials... Troy Daniel Cassata haha, seriously thats my initials. TDC stands for Top Dead Center when the piston reaches the higest point (highs point to the top) just like BDC, Bottom Dead Center when the piston has reached the lowest point. (just call me TDC) some car nerd joke..

[ACCLUDE]

lol!

We got TDC answered, so what does CKP and CYP stand for?

Still need #2 ansewerd....the difference between internal and external coil

and still need the ECU pinout locations of all the distributor wires that go to the ECU and what they are.

[ACCLUDE]

Ok, either you guys don't know or you're not on the forum, so how about some hints???

These might give it away, but oh well

As for question #2 the difference between external and internal...think about conditions that are affected by the placement of the coil (particularly temp.)

And as for the BONUS of listing all distributor wire ECU pinout locations...look more at the B harness....

Also waiting for what CYP and CKP stand for.....

Still waiting on these to be answered before askin some more questions so answer them if you can!

[midnite racer x]

CKP = Crankshaft Position sensor
CYP = Cylinder position sensor

both would have alot to do with the timing and precision of the distributor i would think. It would seem like the distributor would "anticipate" TDC seeing as the rpm's of an engine are variable depending on throttle position and gearing.

and the external coil would benefit from not overheating and cooking the coil inside itself. I guess that'd be for more of a longevity purpose rather than any kind of power upgrade. the internal coil would be connected to the head assembly thus absorbing some of the heat coming from the head.

i'll have to look at the pin outs a little later today, its time for work

[ACCLUDE]

I started this thread because of your question in another post and see....you answered your own question. What better way to learn than to teach yourself:) The only thing to add is that the CKP/CYP serve most of their purpose durring the starting of the motor. It just tells the ECU info needed to synchronize the fuel injection order and speed with the distributor firing order and speed. The cap, rotor, and distributor timing are what set the firing time which the ECU does not control at all, so it has to synchronize the other engine functions (like fuel injection) to what the distributor (CKP/CYP/TDC) sensors tell it.


Just cause its a common question, here's the instructions on how to test the distributor sensors (TDC/CKP/CYP). It's the same for both internal and external coil distr.

Tools needed:
Multimeter/ohmmeter

Look at the distributor and you'll see a grey plug that has 7 (internal coil) or 8 (external coil) wires in it. Unplug that. It should look something like this.
......................................
............________.............
.._____/...............\____...
..|..............................|..
..|...1.....2....3......4......|..
..|..............................|..
..|...5.....6....7......8......|..
..|..............................|..
..|----------------------|..
......................................
(pin 5 should be blank on internal coil and should be green on external coil)

Now, you want to measure the resistance between pins 3 and 7. It should read 350-370 ohms. Measure resistance between pins 2 and 6. Should also read 350-370ohms. Measure resistance between pins 4 and 8. Should also read 350-370 ohms. Now test for continuity between pins 2 and 6 and also between pins 4 and 8. Continuity should not exist between those pins. If any of those do not read what they're supposed to, you need a new distributor.

BONUS: Distributor wire ECU Pinout locations still needed.

NEW BONUS QUESTION (easy): What is the blue distributor wire that has an alternating current signal (instead of direct current like the rest of the car) and is used to tell your gage cluster the engine RPM's? If I tell you any more about it, it will totally give it away. (like I didn't already! lol)

[midnite racer x]

Wait so i was right about the internal and external distribs not adding power but rather reliability? And for ur bonus question is most likely connected to the rpm gauge in our clusters. If thats true tho should i just tap that wire when putting in a new tach? Not that i'm getting one...just learning

[ACCLUDE]

External coils can add more power if you get a beefier aftermarket one. It's much easier to get an aftermarket external coil cuase most of them are universal. Internal coil is much harder to find (distributor specific) and more expensive if you can even find them. If you know that you want to upgrade an your coil to get better spark, then I'd recommend converting it to external coil cause parts are cheaper and easier to find. But yeah, you were right on that.

As for the one distributor wire for the RPM gage, yup...it's the tach wire. That's the one wire you need for a tach to display RPM's but the tach gage may have up to 4 wires to connect total. 1. 12v light wire 2. tach wire 3. 12v ign. switched wire 4. ground. Tachs are very easy to install.

One last bonus question to be answered before moving on to new questions....

[ACCLUDE]

Ok, last thing to be answered is the ECU pin-out locations. No one else wants to answer so here you go:

(these are in the 8 pin harness at the distributor. Pin A21 & A22 join together before they reach the 8 pin plug so you only see one yellow/green wire at the 8 pin plug.)
A21 - Yellow/Green - Ignitor control
A22 - Yellow/Green - Ignitor control
B11 - Orange - CYP Power
B12 - White - CYP Signal
B13 - Orange/Blue - TDC Power
B14 - White/Blue - TDC Signal
B15 - Blue/Green - CKP Power
B16 - Blue/Yellow - CKP Signal

and the rest aren't ECU pin-outs, but this will cover every wire related to the distributor:

Blue - Tach - Goes to Dash Fusebox, Tach Test Conn., & A/T Control Unit (autos only)
Black/Yellow at Distributor 2 wire grey plug - +12V Battery - connects to battery
and of course the spark plug wires

For those of you with external coil distributors:

Coil Pin 1 - Black/Yellow - Dash Fusebox (fuse #17)
Coil Pin 2 - Yellow - +12V battery - connects to the thick gage Black/Yellow wire in the 2 pin distributor plug
Coil Pin 3 - Blue - Is for the Primary Output Control and comes from the Green wire in the 8 pin distributor plug
Coil Pin 4 - The center spark plug wire that connects the cap to the coil

[ACCLUDE]

Now for some new questions....

1. What is the rotation direction of the distributor?

2. What is the firing order and spark plug wire locations on the distributor cap ? Also, which cylinder is which (cyl #1 - 4) if you are standing in front of the car? Both of these questions go hand in hand...you'll see what I mean

3. What is the stock spec for the distributor timing (in degrees)?

4. How do you measure and adjust the distributor timing?

Bonus:
Where is the Tach Test Connection located and what is it typically used for?

Some of these I've answered before so you should be able to find this stuff on the site without much of a problem...... Or you could just whip out the ol' handy-dandy owners manual!!!! lol!