What Kind Of Timing Light?

F-134
I have an innova 3568a digital timing light that works on all my other vehicles and projects including checking it on my lawn tractor.

i can not get it to work with this F-134 setup. It will not flash.
Yes all the plugs are firing and i have tried it on all 4 cylinders to verify.

Please tell me which timing light you are using.

 

I’m still using my 40+ year old Sears/Penske timing light. Still woking fine on my old stuff.
-Donny

 

Mine is a 40+ year old Montgomery Ward / Equus brand and works well.
Seems odd that yours won't flash on the F-134 , especially considering it works on your lawn mower .
Maybe as a test try it on the coil wire to see if it will flash from that input.

 

Innova does say they don't work with MSD ignitions.

Otherwise? Maybe solid wire versus graphite plug wires? Resistor versus non-resistor plugs? Battery voltage six or twelve? Correct polarity? Clamp arrow-mark pointed towards the plug, as per instructions?


I dunno, a stock f-head is pretty damn basic. I'm assuming it does not have military (shielded) plug wires.

Didn't have these dididgital things the last time I timed a Jeep engine with my Sears unit.

 

I still use my 120V timing light I used on my Dirt Bikes in the 70's, no battery, it works on anything with a spark plug. I can't see why you are having a hard time? Good Luck.

 

I think I have the same one..

 

Used an old metal accutron with the variable timing rheostat since the 70's. works on everything I've connected it to.

Good point....
Are you running anything unusual in the secondary ignition department?

 

Time it using a vacuum gauge. Your motor will thank you.

 

Yup. Timing specs are a best guess based on "average" driving habits and the fuel availble at the time. If it never pings you can use more advance.

 

can you give a little more info on how to do this? I’m not a mechanic by any means so this technique is new to me.

 

Disconnect and plug the vacuum advance, if you have one. Attach a vacuum gauge to any manifold vacuum port - not the vacuum advance port. With the engine fully warmed up adjust the timing to max vacuum at idle. Tighten the distributor clamp and reconnect the vacuum advance, Done. Might ping a little depending on your driving habits and fuel quality. Back the timing off little by little until it's acceptable.

 

Thank you

 

For an F head, with a vacuum pump supplemental tube, you'll probably have to "T" off the PCV port for a good connection which you can cap off when done. Here is the link. https://oldjeepcarbs.com/thread/29/time-motor-timing-light

 

I have one of the digital innova lights too (5568) haven't had any problems with it on an f-head or any other motor. I don't have anything with MSD though.

 

No, this isnt a M38A1 with shielded wires. The wires are marked Prestolite R-16 wires so I am not expecting that they are shielded type. I can't find anything that indicates they would be. I am going to try a cheap Harbor Freight gun this weekend to see if it changes. I am baffled so far.
Standard Coil/Cap/Rotor/Points setup. Only thing that might be different from stock is its an external resistor coil not an internal resistor coil. I dont see the difference in coil causing the timing gun to not work.

 

If you happen to have any old plug wires scrounge away from some other application maybe try substituting one for the existing #1 on you F head and see what that may do with your current timing light .
It wouldn't cost anything but time and effort... if you have happen to have other similar wires to try .

 

Naw, doesn't matter whether the resistor is internal or external.

 

I think I might have a plug wire from my wifes VW bug I can “borrow”
Great idea, thank you.

 

Well….. Swapped in different plug wire and timing light works like a champ.

Real head scratcher. I guess Im buying a set of plug wires tomorrow. SMH.