Crane HI6 suddenly doesn't have spark.

[inline6]

So, I was going to try working on jetting of the carbs today.  But, unlike the past several weekends, when I went to start the engine cold, it didn't fire.  No attempt at trying to fire...  

 

I went inside to retrieve the Crane HI6 documentation and see what I could find out.  There is a single red led.  When I turn the ignition on, it lights up solid.  Using the troubleshooting part of the manual, I determine that no fault codes are triggering.  

 

I check for spark using my timing light.  I get none.  The HI6 manual says to crank the engine over and check to see that the led blinks.  It just dims a bit when attempting to start but doesn't blink.  I check power (red wire) and ground (black wire) to the optical pickup.  I confirm power and ground.  

 

So... I am thinking the problem is the optical pickup.  I read where if the white wire it put to ground, it will trigger the coil.  I switch my timing light to the high tension lead from the coil to the center of the distributor cap.  I disconnect the optical pickup at it's harness connection - wires (red, black, white) go from this connection to the HI6 control box.  I pull the trigger on my timing light and ground the white wire.  The timing light flashes, and the led on the HI6 control box goes out.  

 

I remove the slotted disk from the distributor shaft.  I reconnect the optical pickup at its harness.  I hold the disk in one hand and the pickup in the other and simulate the disc rotating within the pickup beam.  The light on the HI6 control box stays solid - it doesn't blink like the documentation says it should when cranking.  

 

So, the pickup just "went bad", right?  Am I supposed to actually see a light beam when the pickup is powered up?  Because I don't.  

 

 

Edited March 22, 2015 by inline6

[inline6]

Picked up a new optical pickup from Summit Racing today.  Just finished trying it.  LED indicator on the HI6 unit still doesn't blink when I turnover the engine... it just dims.  And I still have no spark.  An entire day wasted and no idea what the hell went wrong.

 

There is a rather prominent message in the manual about never unplugging the spark plug leads and turning the engine over... At the start of the day, I did this.  I removed the spark plug leads and the plugs so I could spin the engine to get oil pressure (after an oil change and new filter).  The spark plug leads were laying across the top of the engine.  Maybe that caused something to fry in the HI6 unit. 

 

On the unusual side of things, I note that a strange, high pitched whine comes from the center post of the distributor cap every time I touch the white wire (for the optical trigger) from HI6 unit to ground.  That seems to trigger the coil to fire, but the sound coming from the distributor cap is weird.

 

And when I put the distributor cap back on the distributor, every time I disconnect and reconnect the optical trigger harness, I hear the same high pitched whine for a split second and the engine rotates - indicating the coil just sent spark to a plug.  Doesn't seem right for it to do this.  

[NewZed]

 

There is a rather prominent message in the manual about never unplugging the spark plug leads and turning the engine over... At the start of the day, I did this.  I removed the spark plug leads and the plugs so I could spin the engine to get oil pressure (after an oil change and new filter).  The spark plug leads were laying across the top of the engine.  Maybe that caused something to fry in the HI6 unit. 

 

 

I damaged a GM HEI module doing this.  Forgot to put two plug wires back on and actually ran the engine for a few seconds.  Then it wouldn't start after I put the wires back on even though I had spark, weak and yellow.  It would start and run with starter fluid but that may have been because the engine was warm.  I think it may have been starting from detonation then the higher voltage once the key was off Start let it keep running.

 

Anyway, your actual ignition transistor is inside the Crane box so that might be your problem.  I've never seen a manufacturer's warning about disconnected spark plug wires.  Makes my past problem source more probable.

 

If you're experimentally minded, I've seen that the GM HEI module will trigger from a variety of sources.  They use it as an ignitor with the 0 and 5 signal from the turbo computers.  It might trigger from the optical signal of your distributor.  Not multi-spark but still high energy.

[inline6]

Bought and installed a new Hi-6 unit today... and I still have the same problem.  No spark.  Diagnostics light on the new unit does the same thing.  Lights up solid like it should when the ignition is switched to on.  It just dims when cranking - it does not blink as the manual says it should.  Manual says the unit isn't seeing the trigger signal.  

 

I replaced the ignition rotor also.  The old one has quite a few miles on it.  I'll go ahead and order a new cap also.  

 

Guess I'll be using the multi-meter tomorrow and will try again to figure out what could possibly be wrong.  

 

I hate electrical problems.  

Edited March 15, 2015 by inline6

[inline6]

Spent another weekend on this and I can't find the problem.  This has become the nightmare that I was afraid it would be.  Looks like Crane has different wiring on their optical triggers and this may be what has really tripped me up. Soooo.....

 

My original optical trigger has three wires: black, red, and white.  The black wire a ground.  The red wire is connected to the coil + wire, which gets voltage when the ignition is switched to on.  And, the white wire is the "trigger signal wire".  Initial work with a multi-meter and the hi-6 manual lead me to believe the optical trigger was bad.  So, I bought another optical pickup.  

 

Though this one has three wires like the original, they are grey, black, and white instead of red, black, and white.  Figuring that the grey replaced the red, I wired up the new trigger to the original Crane ignition with grey to red, black to black and white to white.  That didn't work, so I got sent down the path of buying another ignition unit...  more stuff was tried, etc. 

 

During one of my web search episodes today, I came across this: correct wiring of optical trigger with grey wire which this person confirmed with Crane tech support.  The correct way to wire this new optical trigger is actually: black is the +12v line, the white is the ground, and the grey is the signal output.  Why in the world this is the case is beyond me!

 

Is it possible to damage the optical sensor by wiring it wrong?  

***edit - I guess not. Just found this which says it is reverse polarity protected and short circuit protected.***

 

So far, I have tried original crane hi-6 unit with original optical trigger. I have tried the original crane hi-6 unit with a new optical trigger (which was wired incorrectly).  I have tried a new crane hi-6 unit with the original optical trigger, and I have tried the new crane hi-6 unit with the new optical trigger: wired incorrectly and wired correctly.

 

My thinking at this point is that perhaps I fried the original optical sensor while trying to prime the engine with the spark plug leads off.  And that I fried the second one by wiring it incorrectly.  Given this, I went in search of any information I could find on how to test just the optical trigger.  I found this: normal optical trigger function

 

With the original optical trigger, the white wire is the trigger signal wire.  According to the link I posted above, this wire should see zero volts when the optical path between the LED and the photo-receptor is blocked.  This is supposed to be the case when the "disc" with the slots in it does not have the slots aligned with the LED and the photo-receptor.  When the slots align, the white wire is supposed to see 12 volts.  I am seeing around 10 volts on the trigger wire whether the optical path between the LED and the photo-receptor is blocked or open. 

 

With the new optical trigger, the grey wire is the trigger signal wire.  When the new optical trigger is wired correctly, I am seeing around 11 volts on the trigger wire whether the optical path between the LED and the photo-receptor is blocked or open.

 

Any ideas?  Anyone have hi-6 unit that can confirm what voltages are at the three wires for the optical pickup when things are working properly?  Is the light from the LED visible - or is it infrared?  I have yet to see any light coming from either pickup.

 

Garrett

Edited March 15, 2015 by inline6

[inline6]

During all of my searching over the past weekend, I came across some info online that got me thinking the optical trigger I bought two weekends ago might be the wrong one.  I called Crane Tech Support on Monday and had that confirmed.  My new optical trigger (part number 700-0020) with the grey, black, and white wires is for the XR700 and XR3000 ignitions only.  It operates on 5 volts.  The correct one (part number is 715-0020) with red, black, and white wires is now on the way to me.  

 

So, I probably did diagnose the problem correctly: the original optical trigger died.  The new ignition was probably not needed.  I will be able to determine for sure when I get time to install the new, correct optical trigger.

[inline6]

The correct, replacement optical trigger fixed my problem.  The old one was dead.  The first replacement was incorrect - it is for XR700 and XR3000 only.  Original ignition unit is fine.  

 

For anyone searching in the future - the 700-0020 trigger works on 5 volts.  The 715-0020 works off of 12 volts.  That is why you need to use the 715-0020 with the HI6 CD ignitions.

 

G

[Badler]

Hey, just wanted to thank you for the write up. I am having the exact same issue with my Hi-6 so I'm hoping that getting a new optical trigger will fix the problem.