yes for the holley it is required
Well actually it is required to be a min of 100 degrees btdc, but it is good practice to set it at 185 BTDC because Holley actually provided the formula to calculate this location back in like 2012
I will explain later in the thread, first lets get to what fixed it
We need to get Tims truck running!!! With these two things we are hopeful his sport will finally fire
He has similar coil wiring to me, as he followed my diagram!
Let me show you how WE fixed the truck. I say we even though I am the only one working on the truck. A whole slew of people came together to help me through this.
Brett was the one to show me the final "trick" to get her to fire, on a "hunch" (from experience!)
To be fair, the same idea was pitched on the classic bronco forum at around the same time, but I was still confused thinking they were talking cam sensor not crank
First off the crank balancer
"Lucky for us the stock balancer has a carved groove at 180 making this spot/tooth easy to identify
Now turn the engine clockwise (15/16 socket on crank) until your 185 mark is on the engine crank pointer
Now turn the balancer around one more time
The second time the 185 mark comes around to the pointer is the correct location
Now install cam synchronizer alignment tool
Stab 3 wire synchronizer into block, install hold down and hold down bolt
Install cam sensor
DONE
I have a spare crank balancer
Here is the CORRECT diagram to show how we get to 185 degrees BTDC
Factory balancer is 36-1, so each tooth = 10 degrees of rotation
With the timing pointer set to the 0 mark the crank sensor actually sits two teeth back from the 0 mark
the missing tooth that the crank sensor detects, (1 pulse per rotation) is three teeth forward of the 0 mark
So the timing offset on the stock balancer is - 5 teeth (this is important for holley software setup)
HERE IS 185 degrees BTDC on stock 5.0 balancer
Same mark CAREFULLY made on truck AND in position at timing pointer
Time to use the alignment tool and stab our synchronizer
This is the proper flag location
Notice with the alignment tool removed the flag is leaving the window as it passes by the cam sensor
This is DIGITAL FALLING which is preferred for tuning with the Holley, this is important for software setup
Cam synchro done!!
here is important info from Holley about setting up the PCM to run with cam and crank sensors
* There's an updated version of "Crank & Cam Sensor Setup" in the Holley EFI software. On the top Toolbar, click "Help" & "Contents". It's listed in the Help topics. * Originally Posted by Danny Cabral If your crank or cam sync unit isn't transmitting a signal, troubleshoot
forums.holley.com
what we are doing:
"Cam sync location (degrees BTDC #1) = "Ignition Reference Angle" + “A” + (“A” / 2)
“Ignition Reference Angle” = Taken from Crank Sensor Setup in software
“A” = Angle Between Crank Pulses (crank degrees between triggers on the crank sensor)
“A” for a 8 cylinder = 90°
“A” for a 6 cylinder = 120°
“A” for a 4 cylinder = 180°
Using the formula above, plug in the “Ignition Reference Angle” you are using and the proper “A” value depending on the number of engine cylinders.
The location calculated is the “ideal” location and can vary +/- 30° or possibly more.
If you are out of this range contact Holley Tech Service for options.
Yakleys69 notes from Classicbroncos forum:
these are my notes: probably from multiple sources that I extrapolated what was relevant and likely wrote it in a way that I understood.
Cam Sync setup
Purpose is to identify when cylinder #1 is coming up.
Cam makes 1 rotation for every 2 rotation of the crank. Every other TDC cylinder #1 fires.
The cam sync signal trigger MUST occur:
* BEFORE cylinder #1 is at TDC on the COMPRESSION STROKE
* It also must occur at least 50 degrees BEFORE the “missing tooth” read by the crank position sensor.
“Ignition Reference Angle” = Taken from Crank Sensor Setup in software
“A” = Angle Between Crank Pulses (crank degrees between triggers on the crank sensor)
- “A” for a 8 cylinder = 90°
"Ignition Reference Angle" + “A” + (“A” / 2) = Cam sync location (degrees BTDC #1)
50 + 90 + 45 = 185
The rest of my notes on this. no need to print out degree wheel each tooth is 10 degrees. Put on TDC mark teeth as needed. 36-1 trigger has 35 teeth missing one so 36 x 10 = 360
Crank Sensor ( 50° BTDC = Ignition Reference Angle )
Missing tooth is used to identify the Crank Position,
Other teeth are used for RPM and timing
Put Engine at TDC (engines rotates clockwise)
* This will be compression stroke of cylinder 1
* Can tell by placing finger over plug hole
* Also it will be after the intake valve opens, if you can see it
Crank Trigger is 36-1 tooth
* Every tooth is 10 degrees
* With engine at TDC , The crank sensor is on the 5th tooth
* So the ignition offset is 50 degrees
Note: the Ignition Reference Angle set in the software is is typically set to a value that is 10° more than the highest timing you will run. Do NOT set it higher than 75°.
Next My wiring diagram for the coil drivers
I found a couple of mistakes on my coil driver wiring map from earlier in this thread
test