crank Trigger

[av8rds]

It would seem the magnetic pick-up in my MSD pro-billet distributor is going again, second time in 5ish years. It requires pulling the distributor to fix which is a PIA in the garage and not really what I want on the trail.

So, I'm wondering if anyone has experience with crank triggers and how sturdy they are? That is, will it hold up to the dirt and water abuse of wheeling? At least I could easily get to the pick-up to change it out if it stopped working.

 

[bax]

I have an msd pro billet dist and I am not real happy with it. How do you know your pickup is going? I also have changed out the pickup in mine. It is not hard and there really isn't any much to it. Trail fix: have a spare pickup with you. Cut about a 1/4'' of the plastic that goes around the shaft. You can flex the pickup enough to get it around the shaft and still be able to screw all 3 screws into the mounting plate. No need to even move the dist. No other way to fix it on the trail.

 

[Broncobowsher]

couple things I am thinking about.

Does the pro billet piece have it's own advance mechanism?
Because a crank trigger will not. You will have to do all the advance is some seperate computer elsewhere.

Most of the crank triggers I have seen are good for drag racing. Single bolt on a non-indexed part clamping down on a slot. If it comes loose total chaos. Not exactly designed for a set and ignore type application.

But some early 80's fords (I think mine came from an '84 F150) had a factory crank trigger. Pickup coil on the timing cover and 4 teeth on the damper. Took a computer to get the timing right. But the parts do exist for a crank trigger pickup using OEM parts. Now there is an issue that it is not adjustable. All timing changes must be done with software, this includes base timing.

My recomendation would be to recurve a stock Duraspark and run that.

 

[av8rds]

well as per MSD I checked the pick up, had a thread two? weeks agon. So, I was getting varied ohm readings the other day but it did actually start again. Now, it wont start again. The signal goes directly from the distributor in to my EFI box and watching the EFI software it gets no cranking rpm.

There is one connection between where signal splits off to the tranny but as of this point I'm confident in this connection.

I didnt think I could get it out without taking the distributor out, thats good to know.

 

[av8rds]

couple things I am thinking about.

Does the pro billet piece have it's own advance mechanism?
Because a crank trigger will not. You will have to do all the advance is some seperate computer elsewhere.

.

No its locked out for the efi software.

 

[bax]

well as per MSD I checked the pick up, had a thread two? weeks agon. So, I was getting varied ohm readings the other day but it did actually start again. Now, it wont start again. The signal goes directly from the distributor in to my EFI box and watching the EFI software it gets no cranking rpm.

There is one connection between where signal splits off to the tranny but as of this point I'm confident in this connection.

I didnt think I could get it out without taking the distributor out, thats good to know.

This may be a module problem.

 

[av8rds]

This may be a module problem.

what kind of module?

 

[bax]

ignition module. I may be wrong here but I am assuming you are running a TFI / msd pro billet dist? With fuel injection, spark control and magnetic pickup I just assumed you are running a TFI dist. Am I wrong? The ignition module can be mounted directly to the outside of the dist or remotely.

 

[av8rds]

nope no TFI, not Ford injection it's Fuelairspark.com aka FAST or used to be Fel-pro

 

[bax]

FAST is a good system. what dist do you have? I know its an msd. FAST also uses spark and advance computer control. Do you have that option turned on or is the advance done by the dist? i am tring to figure out what you are using.

 

[av8rds]

yeah I want to say its 8574 but I dont see that listed. Might be replaced with the

http://store.summitracing.com/partdetail.asp?autofilter=1&part=MSD-8578&N=700+115&autoview=sku


computer does everything. And, like I said I'm getting no cranking rpm, the only source for that is the distributor. I had the pickup go before, which isnt right for like 1000miles a year!, but also leads me to believe its gone again.

The only thing that throws me is the varied ohm readings I was getting off the pickup. Shouldnt that stay pretty consistant?

oh yeah and I checked the wiring from the pickup and it looks ok.

 

[Broncobowsher]

When checking the pickup, have you checked for AC voltage while cranking? If it is good you should get something.

 

[av8rds]

When checking the pickup, have you checked for AC voltage while cranking? If it is good you should get something.

I did when you helped me last time. It just started not starting again last night so I havent done any diagnostics yet. I will though.

 

[av8rds]

When checking the pickup, have you checked for AC voltage while cranking? If it is good you should get something.

well unlike last time we talked I'm only getting .05 v cranking and like in the M for ohms. Seems like thats the key. Why it was intermittent last time confuses me but none the less at least it looks like a fix.

Oh and I found another old MSD distributor around and it ohms out at a consistent 547, everytime.

Now they question is why have I lost 2 in less than 2-3K miles? and maybe 40-50 hours.

Bax looks like you were right and I can get to it without taking out the distributor which is one good thing!

 

[Broncobowsher]

For fun, ohm out the 2 pins on the FAST where the trigger goes in. I am wondering if the resistance is too low. That would put too much load on the coil. Don't ask what it should be, I don't know. I am just kinda wondering. Maybe a 220 ohm resistor inline to take the load off the coil. But that would depend on what the resistance of the FAST box is. Too much resistance and it may not even see a signal. Probably thinking too hard on this.

Then again you may have got 2 bad coils from the same batch.

 

[bax]

With the hei there still should be an ignition module. http://store.summitracing.com/partdetail.asp?part=MSD-ASY14548
You should not be having the magnetic pickup go bad that soon. With the fast system you could go to an electrical advance. let the computer do it all. You are programing with a lop top now correct? You can set up your advance map and control your idle better if you have a big cam. Just an idea if you plan to change things.

 

[av8rds]

Then again you may have got 2 bad coils from the same batch.

Its not the coil. The coil/whole ignition doesnt see anything until the fast computer sees cranking rpm.

 

[av8rds]

With the hei there still should be an ignition module. http://store.summitracing.com/partdetail.asp?part=MSD-ASY14548
You should not be having the magnetic pickup go bad that soon. With the fast system you could go to an electrical advance. let the computer do it all. You are programing with a lop top now correct? You can set up your advance map and control your idle better if you have a big cam. Just an idea if you plan to change things.

the computer does everything now. BUT it wont do anything until it sees cranking rpm. That is, nothing in the ignition works until the FAST computer knows its turning and then activates everything else.

 

[av8rds]

oh and I did read something on the MSD forums about the Mag pickup have a rep for going bad on lesser used vehicles, which mine is. I'll have to call them tomorrow to see if they have a solution.

 

[bax]

Dont the cranking pulses come from the magnetic pickup in the dist? so you are probably correct about the pickup going bad. Is kind of strange for them to go bad so soon. my experience with MSD tech is not that good. I hope you have better luck than me.