Thanks for the update Scooter I think I will try to make one. Any tips or info you can add?

Thanks
Dave

 

What is it you are trying to find out?

Do you think you need new COP's or plugs?

 

I have an OTC labscope but have no way of looking at secondary waveforms on coil over. Plugs have been changed. No check engine light but a skip under load. And off and on at other times. Mode 6 says skip on cyl 5 but I need to know if it is an injector or coil. This vehicle has had some injector issues but I want to be sure.

 

Here is the same thing made up for $41.44.

3825-56 Scope Universal Cop Probe OTC Tools


/

 

Apparently, from the post above, there is a cheap OTC probe out there that should work better than my "home brew" version. I assume it should come with some kind of information as to what to look for. I was just flying blind.

Would not replacing the suspected #5 COP be an easy way of testing the coil?

With me it was bucking when you hit a hill and tried to give it power. Level ground was OK but it you tried to accelerate too fast even then it would
bog down.

 

Yeah I guess I will order the OTC probe. As far as the coil I could just move it to another cly and see if the skip moves to the new cyl. I Would like to see what the pattern looks like

 

Note that link to that online store above does not have very good reviews.
There are others selling that probe.

 

I will shop for it elsewhere

Thanks

Dave

 

Dave,

I ordered it from O'Reilly auto parts store in my home town locally.
It was $59.99 + $6.68 shipping + tax.

As I understand carquest and NAPA stores can also order it but none have it in stock at their warehouses.

 

Thanks for the info I will try NAPA.

Thanks
Dave

 

Found this for $41.85

OTC 3825-56 Scan Tool Accessory - Electronic Testing

Anyone used this store?

 

I don't have a Ford, ...or a truck but I found this thread on a google search. I built the OP's circuit,it looked good but I couldn't get a signal out of it. The problem I had was it needed rectification and the signal was further weakened by the 10K resistor.

The circuit overall was good, it just needed tweaked so here's a couple pictures of the revision of the circuit that worked for me and the clamp I built it into.
I use it with a Hantek 1008 Scope and it gives a nice trace, in fact I built 8 of them since it's an 8 channel scope and I can view 8 cylinders at once.
Thank you Scooterspal for such a cool project, hopefully I haven't offended anybody by posting here but it seemed appropriate to put this with the rest of the OP's legwork.
I may revise this a little more with a large variable resistor where the OP had the 10K so each probe can be "Calibrated" but for now I'm thanful to view traces and have such a useful tool.

I have to add.. I assume no responsibility if you damage your scope, but it works fine with my Hantek, the ground clamps came after these pics and really got rid of the "noise" and made the trace pop.