Crank Trigger Info

I have decided to either make or buy a crank trigger setup for my fuel injection system. The erratic (oddfire) tach signal that is being sent to the ECM is, well, too erratic. I know next to nothing about the basics of crank triggers so I'm posting this up in hope that some of you have done this or can at least point me in the right direction. So, let 'er rip, gentlemen and edumacate me.

 

my buddy built a GM system for a dauntless . it ran fine just a touch rich.i did post something about it ,,,I will find it

 

my buddys dauntless with tbi

 

What did you say it will end up in my Olds 442 ?nice .thanks

 

Mr.Warlock why did you take it off ???

 

Thanks for the info, guys. I'm doing my "due dilligence". More please.

 

Thanks for the suggestion termin8ed. I sent their tech an email to see if they think their trigger setup will work with the Powerjection unit.

 

Posi, what distributor are you using?

 

I'm using a Davis Unified (DUI) HEI distributor. I'm not looking to control spark timing, just giving the ECU a clean rpm signal.

 

DUI looks like good stuff!
Has it ever run right?
How have you determined that it is the odd fire tach signal causing the problem?
GM ECU?
How is ECU wired to distributor?

 

It runs really great on the trail. On the street I feel like it has never had the power that it had with the carburetor. I'm also going to put an timing advance limiter on the vacuum advance as it tends to want to advance the timing above 3000 rpms way too much for this engine.

One of the members here (Jonah) had the same FI on his oddfire and told me that it ran much better after he put a crank trigger on it. He has the technical ability to make a trigger wheel. I'm just trying to learn enough about them to figure out what I can make work.

Proprietary ECU by Professional Products ( Powerjection III)

I have a wire from the tach signal output on the distributor to the ECU.

 

Does your powerjection III dashboard show the correct engine rpm? If it does the ECU is reading the oddfire tach signal correctly. If the ECU reads the tach signal at low rpms it will read it at high rpms. Is the fuel pressure and volume good?

 

The dashboard rpms is very close to my tach reading. Fuel pressure is right at the recommended 45psi. I have a neighbor who just restored a Dodge Challenger and used a Megasquirt FI system. He also told me that it ran better with a crank trigger than it did using the dist. tach signal. While the dashboard shows fairly accurate rpms when I go to the Real Time window I can see a lot of variation in the rpm signal.

I'm picking up a vacuum advance limiter at Summit Racing today. I seem to have a lot more vacuum with the FI than I ever had with the carburetor and at higher rpms it is advancing waay to much. Doesn't affect the way it runs on the trail though as I'm usually between 800 and 1800 rpms.

 

How much vacumn do you have? How much is it advancing? Is it pinging?

 

Hey John, which ones did you pick up? I installed the DUI distributor on my 225 and have been playing with the timing. Seems like once the RPM's come up it is advancing further then I want it to.
Rob

 

Rob,
I bought this one: Crane Vacuum Timing Limiter Plates 99619-1 and this one made by DUI: Davis Unified Ignition Vacuum Advance Eliminators 333333
I bought thenm both at Summit Racing. The Crane Limiter was less than $3, the one from DUI is a lockout, but it may be adjustable by drilling new mount holes. It is about $10 I haven't had a chance to put either one in yet as I have too many Honey- Do's in the way.

 

Thanks John.
Would you document the process if you get the chance. And the end results.
I will be watching.