Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   Porsche 911 Technical Forum (http://forums.pelicanparts.com/porsche-911-technical-forum/)
-   -   spark test where to ground? (http://forums.pelicanparts.com/porsche-911-technical-forum/432061-spark-test-where-ground.html)

81white911 09-24-2008 03:52 AM

spark test where to ground?
 
If i pull the spark plug cable and leave the original plug in the block, and use a test plug with a ground wire wrapped around the threads. Can i ground it anywhere or is there some special place. Ive tried the intake header, the bracket on the engine fan cowling. I occasionally get a nice bright spark, but not consistantly as i crank the engine.

sballard 09-24-2008 04:02 AM

It shouldn't matter as long as it is conductive metal and grounded. I would think that the header is fine. For this test I image you are looking for any sign of spark.

For those of you who have never done this, DON"T TAKE THE ORIGINAL PLUG OUT. Find a spare plug to test. I remember watching in horror as an ignorant mechanic set my girlfriend's boat on fire by taking the original plug out, hooking it up to the wire and grounding it next to the open hole. When she cranked the engine, the flame that shot out of the combustion chamber was impressive! It even set the mechanic on fire - what a lesson!

81white911 09-24-2008 05:05 AM

spark but not sparky
 
just not getting a spark every rotation, Does anyone know if coils have intermittant failure ? or due they just die.

jtfreels 09-24-2008 05:46 AM

An alternative test, do you have a timing light? If so just hook it up as you would to test timing have someone turn the engine over.

When the timing light never went off I kinda new I wasn't getting any spark.


Jay

RWebb 09-24-2008 07:43 AM

Quote:

Originally Posted by sballard (Post 4198206)
It shouldn't matter as long as it is conductive metal and grounded. I would think that the header is fine. For this test I image you are looking for any sign of spark.

For those of you who have never done this, DON"T TAKE THE ORIGINAL PLUG OUT. Find a spare plug to test. I remember watching in horror as an ignorant mechanic set my girlfriend's boat on fire by taking the original plug out, hooking it up to the wire and grounding it next to the open hole. When she cranked the engine, the flame that shot out of the combustion chamber was impressive! It even set the mechanic on fire - what a lesson!

hey - I know that guy. Sparky.

ischmitz 09-24-2008 08:02 AM

Quote:

Originally Posted by 81white911 (Post 4198281)
just not getting a spark every rotation, Does anyone know if coils have intermittant failure ? or due they just die.

you should see spark every other rotation..... remember it's a four-stroke with a 720 degree cycle

81white911 09-24-2008 08:31 AM

sparky the wet fingered electrician
 
i was told to take the cable off the center of the distributor and hold it near the engine to see if i get spark and isolate any distributor problems. maybe i should put a spark plug on the end and ground it. Something about holding it sounds sparky to me.

81white911 09-24-2008 11:24 AM

sparky
 
intermitant spark off the coil cable, the CDI is shipping for analysis repair or replacement.

rnln 09-24-2008 11:31 AM

wow... scary. I have seen people do it this way all the time and I did it several times too.

Quote:

Originally Posted by sballard (Post 4198206)
It shouldn't matter as long as it is conductive metal and grounded. I would think that the header is fine. For this test I image you are looking for any sign of spark.

For those of you who have never done this, DON"T TAKE THE ORIGINAL PLUG OUT. Find a spare plug to test. I remember watching in horror as an ignorant mechanic set my girlfriend's boat on fire by taking the original plug out, hooking it up to the wire and grounding it next to the open hole. When she cranked the engine, the flame that shot out of the combustion chamber was impressive! It even set the mechanic on fire - what a lesson!


BK911 09-24-2008 03:13 PM

Quote:

Originally Posted by jtfreels (Post 4198358)
An alternative test, do you have a timing light? If so just hook it up as you would to test timing have someone turn the engine over.

When the timing light never went off I kinda new I wasn't getting any spark.


Jay

+1

IMO the best way. No need to disconnect anything, only takes a couple of seconds, and is relatively safe.


All times are GMT -8. The time now is 05:17 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.