Weird timing light readings

[GregW]

I have a strange problem with my inductive timing light. It is a Stinger by OTC. It has all the bells and whistles; dwell, RPM, adjustable advance and voltage. I have painted the TDC mark on my damper. When I take a reading, it looks like 15 degrees ATDC (mark on damper above timing cover mark as viewed from the right side of the car). If I dial in 15 degrees of advance on the timing light, the reading doesn’t change. If I rev the engine, the reading doesn’t change. If I rotate the distributor, the reading doesn’t change (I did this with the sparkplugs out). I’m using a multi-spark electronic ignition, but I wouldn’t think that would have an effect. Any thoughts of what I might be doing wrong? The directions are a little less than and there is no troubleshooting guide on OTC’s website. /ubbthreads/images/graemlins/computer.gif

Thanks,
Greg

 

[Keoke]

/ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/confused.gif

How can you rev the engine and expect to get a timing reading if the sparking plugs are out?--Keoke- /ubbthreads/images/graemlins/confused.gif

 

[GregW]

Hi Keoke,
I wrote that out of sequence. Before I started the motor, I had the plugs out to build oil pressure. With the starter cranking, I got that weird reading. I rotated the distributor a full 60 degrees with no change in the reading. I did a static timing to reposition the distributor. Then the sparkplugs went in. Fired the motor, good throttle response, no hesitation, no obvious pinging. No matter what the engine is doing, the timing reading remains constant.

 

[Keoke]

OK Greg, I wid you now but I do not know what the problem is I have guests today but you can come by and pickup my Snapon lite and use it if you like. However, I am aware that some of these special electronic ignitions require a special comb filter to read correctly particularly to read dwell.---Keoke

 

[Dave Russell]

Some timing lights just won't trigger correctly on some electronic ignitions. A little experimenting is in order.

I had the same problem with a MSD6 ignition. A very old Sears light responded correctly.
D

 

[Keoke]

Hi Dave yes that is true, the older the light the more likely it won't trigger.While a standard inductive timing lite will generally allow you to set timing when a Pertronix unit is installed you can not read the dwell without the comb filter.---Keoke

Well if the sears unit worked I just happen to have their top of the line timing light too.

BUT THEY BOTH Dial Backs. /ubbthreads/images/graemlins/cryin.gif---- OH! someplace in the shop I have one of those old non inductive timing lights ,the ones with the little spring that you hook to the sparking plug and then connect the spark plug lead to it also some other cables to hook up havent seen it in a coons age but its in there.- /ubbthreads/images/graemlins/yesnod.gif-Keoke- /ubbthreads/images/graemlins/grin.gif

 

[GregW]

Hi Keoke,
Thanks for the offer. The Jacobs ignition website didn’t mention anything but I went to the MSD website thinking if Dave had a problem, maybe it is a known issue. Sure enough, MSD recommends NOT using a dial back timing light for CD multi-spark ignitions. Guess I need to go buy a cheapy. I think I know someone with an original ignition system who will buy my light.

 

[GregW]

Hi Dave,
Thanks for the MSD tip.

 

[Dave Russell]

[ QUOTE ]

BUT THEY BOTH Dial Backs. /ubbthreads/images/graemlins/cryin.gif---- OH! someplace in the shop I have one of those old non inductive timing lights ,the ones with the little spring that you hook to the sparking plug and then connect the spark plug lead to it also some other cables to hook up havent seen it in a coons age but its in there.- /ubbthreads/images/graemlins/yesnod.gif-Keoke- /ubbthreads/images/graemlins/grin.gif

[/ QUOTE ]
My old Sears light that worked is not a "dial back" but it IS an inductive pickup. You have to put marks on the pulley. This being said, I still prefer it to the dial back lights. In my mind, it is more likely to be accurate.
D