Hi folks! My truck start to fail again just like some 25,000 miles ago (fixed in jan/09) I visited the same shope and the same mechanical drive test the truck. The fail is most of the time at 70+ MPH he in the city can not replicate the fail because he can't drive no more than 60-65

The truck hesitate and lack of power at 70+ MPH and he fix it channging cops and plugs.

This time I don't have any code. but the truck feels just like before only not as notorius.

He don't want to change cops because he don;t have any hard data to make the change (no computer code).

I want to test the COPs myself. O'm an electronic engineer and I have scopes, waveform generators and all the stuff i think is needed.

Any of you have any experience?

I think to inyect to a coil a 1khz to 5khz square waveform at 12 VCD and look the output in the scope.

The only problem is I don't have a test probe larger than 500V. How much voltage is in the secondary of the coil?

Thanks for your help!
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Art,

I have had a similar problem previously. Once when we took the truck to Veracruz to my wifes family ranch. We were on a gravel/mud road with a lot of water and the engine got really wet. Pulled the cop and dried the wires. Problem solved. this happened again one time when I was cleaning the engine at the car wash with the pressure sprayer. I have stopped getting the engine wet and the problem has stopped. as for the voltage, I am not really sure but the old style single coil for automotive was around 25K volts. These cop may be alittle bit more on the secondary voltage. I doubt that your cop,s are bad , Check the wires that attach to them and look for signs of carbon traces which would indicate shorting to ground. Also when reinstalling the wires make sure to use the dielectric grease. Hope this helps. Also Enjoy your beautiful city of Monterey. When we lived in McAllen we would take many trips to visit your city. Now we are in El Paso Tx and it is too far to visit Mtry N.L Good Luck!

 

I've been hoping someone could answer that question. I would like to know also.
I had a friend that used to love to charge condensers, and throw them to people.(ouch)

 

um.... waste of time??

 

there is no way to repeat the symptoms.... the arc from the coils gets weak due to the compression in the engine.... it blows it out like a candle

 

That's 10 V/div.

What kit are you working with? 418-F5528 ? You really need this kit ,-more accurate diagnosis . Try 1-800-ROTUNDA, - Still works!

You need to stress test. Do you have this preconfigired setting = COP_STRESS_TEST_RED. ?

 

I'd say there are only 30-35k on the new plugs...changed at either 80 or 85k, can't remember. I changed 'em.

I have a scan tool, it's how I knew it's the cylinder with the new coil.

I think my plan will be to change the plug to a new one, and swap the coil with another cylinder at the same time.

 

Wtf...that posted in the wrong thread