ive been having trouble keeping spark or even obtianing spark with my DIS module. ive tried new modules ( to verify working condition of used one) checked the coils etc etc etc. im not getting a tach output some im assuming something is up. ive got 500+ millivolts at during cranking GM spec say 300 is enough.to complicate matters my engine run CCW not CW like a domestic 4cyl. so i made sure to reverse the wheels firing pattern ( in thoery should work fine worked ok on the bench rig) my question is who has played with notch sizing ? on a 3inch diamtere wheel whats the ideal notch size in inches or metric ? i can make this run all day on the bench with my home made trigger wheel but im having no luck making it run on the car so i think something is up with the notch sizing.

 

Yep, it shouldn't matter about the rotation. If using a removable wheel you just basically flip the wheel and it's right. But I don't quite get what you're saying? Are you saying you are losing spark or that you have spark but the engine doesn't crank?

The notch sizes IIRC are supposed to be 7 degrees apart so the length is dependant on diameter or circumference I guess. I had a wheel made a while ago and on the bench it worked. It always fired of the plugs. Actually they weren't plugs but allen wrenches at the end of the plug wires going to the battery ground. I have a picture of that somewhere. I never had a chance to get it on a car but chances are that it may not have worked because what happens is that you tend to lose the synch pulse due to wheel fluctuations and the module resets. This is according to someone who has studdied this a lot over at DIY-EFI and I take his word for it. Anyhow, I lost interest in the project for another project. That's sort of how it works with hobbies, they don't end, you just trade one for another.

Anyhow, way of track. One thing, do the crank sensor wires have shielding? The OEM application shields the wires so you don't lose the signal through wire length.

 

yep

i may have to check runout but the scope readings i took looked good

ive heard everything from 2-3 and now 7 this is most likely the problem



shannen i presume ?

 

If ya don't mind, post what ends up being the problem, and the notch size please! I promise, I will do something useful with the info!

 

anybody here got a 3.1 v6 with DIS FWD crank out of the car ?if so shoot me the measurements of the diameter or the reluctur ( radious) and the width of the notches. id much appreciate that.

 

I got your e-mail, and will get you some measurements tommorrow, when I am back at the shop.

I know the wheel is about 6" in diameter, the one I made is slightly larger to space out the sensor a little bit from the crank pulley to make sure the sensor only picks up the trigger wheel and nothing else. notch size doesn't seem to matter too much, we used the same size notches as the OE trigger wheel, so in degrees it would be 1 to 2 less than factory, and my ignition is working fine. The way we loooked at it, was that we can always take more off later, but it's harder to add it if we needed to. This was also something that I had not heard of anyone attempting before we made mine, I just wasn't looking in the right places.

Mine is made from steel, not sure of the variety (grandfather took care of that, but it couldn't be aluminium for obvious reasons, even though it would have been easier to work with. the bracket for the sensor is alumnium, and is adjustable, just in case.

I will get those measurements tommorrow, hopefully with some crank degree timing measurements too. After looking at the crank in the block tonight it looks as though the home signal is 10* after #1 TDC, but I'll have to study it more once I get a piston in the block.

 

I don't know if the Australian Holden V6's with DFI (Buick engines) have the same system you're looking at, but they have 2 concentric interruptor rings (18x and 3x), and the inner 3x slots are 10*, 20* and 30* wide respectively. Could it be that your system needs different sized slots?

John

 

actully im using a 2.0 2.2 2.5 4cyl dis module. it jut shares the same trigger patern with the 60* 2.8 3.1 3.4 family of v6s engines. the 90* v6 your refering to would absolutely have different notch spacing.

thanks very much for the input but im afriad this isnt the info i need.

 

well after 3 hrs in the machine shop today i have spark !!!!!! yaaa. now i just have to make a new sensor bracket. seems to be a bit to far advanced. but to far advanced is better then no spark at all.

 

Good to hear! What was the issue? --if you don't mind.....

 

proper scaling of the notches in the wheel itself in relationship to its size. i was figuring the notch size incorrectly. ( stupid me) anyways for a wheel 6 inches in diameter you need 3/16 notches. to arrive at the correct notching size.

Daimeter x 3.14 / 360 time x4 = notch size.

id suggest running s wheel no smaller then 5 inches.

 

Do you guys ever plan on putting up pictures of this to get more of an illustrated idea? I think it would be interesting.

 

funstick, I didn't forget about you, there's been issues getting to the point that I could drop a piston in the block.

But it sounds like you got it figured out, good to hear.

Do you still want to send you the info, for future reference?

 

i plan to put up some pics and mpegs in the near future. right now im wringing the bugs out of it.

 

yet again more incorrect info abounds at the DIY ftp. the correct notch sizing formula is ( this is for the factory designed wheels on the crank )

i got my hands on a couple of cranks today and hashed this issue out.

diameter x 3.14 / 360 x 7 = notch size.

thats the correct formaul. sorry for misposting. the original info i gathered was inccorect.

 

So, from your formula, I figure it's 7 degrees of crankshaft revolution that the notch needs to be? This stuff is always interesting to me, and it keeps my brain occupied!

 

yeah thats for 60* v6 modules and the 4 cyl 2.0 2.2 2.5 wheels. however i dont think the n* notchs are that big. the wheel would have to be like 12 inches in diameter to fit them all on there LOL get a crank

 

Yeah, I realized that. I just wanted to lock it into memory for future use! That may be a handy thing to know when diagnosing a no start (I do that stuff for a living....)

 

i had a used car lot car come into today( 2.2 iter cavailer with DIS) with a rod knock.sort of rigged the rod into being quiet ( dont ask ) thats when i decided to measure the crank. i then went and mesaured a crank for a 3.1 DIS motor. found the same thing. so GM uses that across all the older 7 notch systems. it can be pretty critical when designing a triger wheel to know how to correctly size the notchs. thats why i posted a formula to firgure it out in thousandths. awefully nice of me to goto the trouble is you ask me.

 

Yes it is awfully nice of you!

I did know that the 4 cyl, and V-6 use the same exact trigger wheel though. I had learned that in a GM seminar a long time ago. They both see the same signals, but they don't particularly use them.

 

I also found that similarity between the 60*V6 and OHV I4 crank triggers when I had both side by side, a crank from a 3.1L and from an old project that I started and never finished, a 2.0L OHV. The flywheel bolt patterns are also the same.

 

It'll be awfully nice of you to make the information available of getting a V8 to work with DIS. So far you've just done what everyone has done and run either a 4 or a 6 cylinder with DIS. Easy to do since there are 4 and 6 cylinder cars with DIS already. Pat yourself on the back when you get the V8 stuff to work since you seem to have everyone convinced it's so easy to do. And BTW, I guess Shannen was right when he told me the notch size was 7 degrees, like I told you way up at the top. Nice to know some people give good info.

 

Keep your eyes peeled cuase im gonna show off and and show you how to do it with 2 4cylinder modules.i can make the n* dis run anytime i want to pull a crank out and have my machinist make a pattern. somebody willing to send me a crank ? or maybe ill try to find one thats in a junk motor. either way ive been sharing what ive learned along the way. i could in fact tell you nothing. that would be easier. and ive spoken to shannen quiet a bit about the trials and tribulations of this setup. like setteting everything up to run CCW. im in my thrid generation of trigger wheel now. this one works perfectly. the n* should be a snap. considering i know which mas ID's will run the EST without trouble. however the only hold back with the 2 4cyl modules is getting the est to work correctly ive gotta sit down sometime this week and punch all the math into the calculator to see how it would work out. should be just fine actually. but gotta be sure.

alot of people putting GM dis ignitions on hondas these days ?as far as i know im the first and only person to do it

 

Not that this is on-topic but what's the difference in putting DIS on a car that has a dist. whether it be Honda, Kia, or GM stuff. If the car never had DIS then putting DIS on it is just as hard or as easy as putting it on a GM product that also never had DIS. And the dual 4-cyl DIS bit is also old news to anyone that has ever looked through the GMECM archives. Matter of fact that's what I was working on almost two years ago before I got bit by the autocross bug. That and I learned it would be easier to go with CNP, although more expensive.

But the tone of my previous post wasn't to say that you weren't sharing. It was to say that you shouldn't hurt your arm patting yourself on the back for sharing. You think doing that little calculation was something completely unselfish and out of the deepest human sacrifice. And I'll say it again, I had already told you it was 7 degrees as told to me by Shannen so you just gave something someone had already given. Nice Job! Sorry I'm not impressed by you DJFreggens, never have been. And I won't say another word as I don't want this thread to get locked or any other thread for that matter.

 

your post doenst even deserve a respones this big.

as for everybody else ill try to make a v8 run with dual 4 cylinder modules. shouldnt be to complicated. just gotta crunch the math and figure out where things fall in the rotation.

 

One question on the dual 4 cyl modules...and this may have been addressed already, but would you just parallel the wiring for the EST, REF, and BYPASS? Seems simple enough other than that!

 

im not 100% sure of how to handle the signal trian. my first thought is to clamp the Ref lines with diode to keep them from backfeeding each other. the EST should be able to be shared. the bypass can be shared as well. its only looking for a pull down to ground. i also have to run a **** load of test to make sure what ive got skeched out here on paper will work. ive been up half the night tonight going through the way the moduel will read the wheel generated pulses and send signlas to the ecm. plus i have to worry about the Est falling on the right module at the right time. ill have to look at the est line again and see how much dweel control its really implementing to be 100% this will work. at worst it might need a 555 timer to switch the dwell control from module to module. still fiarly simple electronics but i have to make sure itll work as planned. good news is looks like one 7 notch wheel is all that will be needed.

 

Someone wanted a picture so here is something I was working on a year ago. I hope the picture comes through. If not I'll try to post a link. The wheel is 8" in diameter to clear my 7" damper. Yes, it is being powered by an air drill.

 

These are my spark plugs.

 

Doc and the lil guys left the room, so who knows what ya got them lads thinking. LOL

KEWL

 

triggers ignitions and slices salami too...

 

i already started cracking on 2 4cyl module for a v8 sbc bbc b rb chrsyler most any engine with 8 cylinders and a 18436572 firing order. gonna have to handle the est line and toggle it between modules. other then that looks pretty simple. ill either get a converter whipped up or post some schematics in the near future.