quick question re:removing plug wire at cap
 

hi


Curious, a lot of youtube videos on troubleshooting a misfire start with the engine running and then pulling one wire off at a time.


Can we do that with our 2005 blazers?


Does it ruin anything?


Do blazer owner/mechanics use this as a valid test?


Or is it easier to just put a timing light on the wire see if the pulse is there?

Can't see why it would hurt anything on a 2005 - I do it all the time when needed - by pulling one wire at a time you are not looking for spark you are seeing if the miss increases by shuting down that cylinder - if the miss doesn't change when the wire is pulled that will be your problem cylinder - most times you can check for a rod knocking in this manner also, pull the wire and the knock quiets down that will be the bad cylinder:icon_clapclap:

Thanks for clarifying, will I get shocked by taking the plug wire off at spark plug or should i do it at cap? I know my post said "at cap".

Thanks

either spot you can end up with curley hair - I usually loosen all plug wires first and do my best not to get knocked on my a--:icon_hyper:

Just letting everyone know I did the test, started it up, pulled a plug wire off at CAP and you could tell FAST that the engine totally sputtered 10 times worse.


So this helps rule out a dead cylinder or a misfire on one of the cylinders as being a plug or plug wire doesn't IT!


??

as I stated above when you pull a plug wire off and the miss increases the cyl is fireing - if the miss does not increase when plug wire is pulled the cyl is misfireing

As above...ONLY when you pull the plug wire out of the distributor cap and there is no difference in how the engine is running.....that is when you have found the bad cylinder.

yup, I pulled every plug (except one) and you could tell immediately it ran like ass. I couldn't get one in passenger side nearest firewall to come off because of stupid tranny dipstick in the way


who knows maybe that is one, lol