I'm looking for a diagnostic machine dat can run tests to tell me der condition of my ride's plug cables. I used 2 do these tests back in der 80s but I'm lost as 2 who can do dem these days. Can anybody help point me der vay to a werkshop/ mech who has dis machine/ a machine mit dis function? :blink:
HT Plug Cables
- Thread starter 2cents
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An ohm meter just tell you the resistance of the cable from end to end. Of course the lower the resistance, the less power is lost thru the cable. But for HT cable, it is more important, the insulation resistance. In this case, you need an megger ohm meter which can inject DC voltage from 250 to 1000V. There are some megger that can inject the DC voltage at 5000V.
To summarised, low reistance is milli or micro ohms. High insulation is meg or giga ohm.
I have learn one simple way to test the condition of the cable without any special tool. Just use a long screw driver with an insulated handle. Place any of the expose part of the screw driver by touching one the HT cable at a time. Bring the end of the tip of the screw driver to any body part of the car. Observe whether there are tiny sparks. If there are sign of spark, then the insulation of the HT cable is breaking down and need to be replaced soon.
Danke schone guys but I'm trying to c the integrity of der cable in conducting electricity. Dis attempt is related to der quirks I've been having mit my ignition lately. 
As I hv described in da other threads (I can't rem'ber wich) I am experiencing an occasional problem mit my ignition in dat my engine sometimes vill crank but not fire. :dunno:
I hv changed der fuel regulator but not der fuel pump (only 2 yrs old), der distributor cap (rotor arm's also 2 yrs old), tried swapping mit Kevster's old ignition coil und am going to tackle der HT cables for der moment b4 I move on to der ignition control, switch, starter, relay & etc.
But der strangest thing happens if I leave der "situation" alone und try to start 2-3mins later - it fires upon cranking! :lol:
So vat do I to shortcut der process - I unplug my HT cable connexion to der ignition coil und rest it over der mouth of der coil & und crank again - & voila, has never failed me dis vay in der past 30 days. :wink:
Meanwhile back at der batcave...I found dat if I ver to turn my ignition key straight thru without hesitating at der first schtop like we all usually do, I experience less chances of engine crank without firing! :yahoo:
So nowadays, ven I start der my ride, I turn der key right thru to de end. Yes it verks but der mystery still not solved!! So now I suspect dat it cud be der plug cables - und dats vy I ned to test dem. :getyourfactsright:
So guys, I'd appreciate it if u can tell me, izzit der resistence r der arcing I need to zoom in, r something else? :blink:
As I hv described in da other threads (I can't rem'ber wich) I am experiencing an occasional problem mit my ignition in dat my engine sometimes vill crank but not fire. :dunno:
I hv changed der fuel regulator but not der fuel pump (only 2 yrs old), der distributor cap (rotor arm's also 2 yrs old), tried swapping mit Kevster's old ignition coil und am going to tackle der HT cables for der moment b4 I move on to der ignition control, switch, starter, relay & etc.
But der strangest thing happens if I leave der "situation" alone und try to start 2-3mins later - it fires upon cranking! :lol:
So vat do I to shortcut der process - I unplug my HT cable connexion to der ignition coil und rest it over der mouth of der coil & und crank again - & voila, has never failed me dis vay in der past 30 days. :wink:
Meanwhile back at der batcave...I found dat if I ver to turn my ignition key straight thru without hesitating at der first schtop like we all usually do, I experience less chances of engine crank without firing! :yahoo:
So nowadays, ven I start der my ride, I turn der key right thru to de end. Yes it verks but der mystery still not solved!! So now I suspect dat it cud be der plug cables - und dats vy I ned to test dem. :getyourfactsright:
So guys, I'd appreciate it if u can tell me, izzit der resistence r der arcing I need to zoom in, r something else? :blink:
For high resistance, you need a good insulation resistance. i.e. no leakage.Originally posted by 2cents@Apr 2 2005, 05:14 PM
Danke schone guys but I'm trying to c the integrity of der cable in conducting electricity. Dis attempt is related to der quirks I've been having mit my ignition lately.
As I hv described in da other threads (I can't rem'ber wich) I am experiencing an occasional problem mit my ignition in dat my engine sometimes vill crank but not fire. :dunno:
I hv changed der fuel regulator but not der fuel pump (only 2 yrs old), der distributor cap (rotor arm's also 2 yrs old), tried swapping mit Kevster's old ignition coil und am going to tackle der HT cables for der moment b4 I move on to der ignition control, switch, starter, relay & etc.
But der strangest thing happens if I leave der "situation" alone und try to start 2-3mins later - it fires upon cranking! :lol:
So vat do I to shortcut der process - I unplug my HT cable connexion to der ignition coil und rest it over der mouth of der coil & und crank again - & voila, has never failed me dis vay in der past 30 days. :wink:
Meanwhile back at der batcave...I found dat if I ver to turn my ignition key straight thru without hesitating at der first schtop like we all usually do, I experience less chances of engine crank without firing! :yahoo:
So nowadays, ven I start der my ride, I turn der key right thru to de end. Yes it verks but der mystery still not solved!! So now I suspect dat it cud be der plug cables - und dats vy I ned to test dem. :getyourfactsright:
So guys, I'd appreciate it if u can tell me, izzit der resistence r der arcing I need to zoom in, r something else? :blink:
you may ask why?. Well, the required current flow for ignition is very small but you need a very high voltage in order to create the spark or arc (in this case, the break down of the the air.)
If there is breakdown in the insulation of the HT cable, the energy is prematurely divertly to the ground before it could reach the spark plugs. This will cause misfiring or high vibration because one piston is not firing. However, it would will NOT stop the engine from starting. (The possibilty of 4 or 6 HT cables failing at the same time is almost impossible)
Based on your discription of your problem, you could be facing a crank sensor problem. If you have a crank sensor failure, the ecu would go to fail safe mode and cut power to the fuel pump and the ignition coil.
wolverine
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Hello 2cents,
Did u try tapping the ignition unit in the left side of ur engine compartment while cranking? How were the cables I passed 2 u?Also try spraying contact cleaner into the ignition unit sockets...
Uncle Jarance,
I don't think it's the TDC sensor coz if it fails,it fails just like that at one go.It doesn't wear off in time...normally.
Did u try tapping the ignition unit in the left side of ur engine compartment while cranking? How were the cables I passed 2 u?Also try spraying contact cleaner into the ignition unit sockets...
Uncle Jarance,
I don't think it's the TDC sensor coz if it fails,it fails just like that at one go.It doesn't wear off in time...normally.
Actually, happened to me once.. the tdc sensor. could not start the car but after a few try, the car somehow managed to start again. However, later the car stalled after i drive for about 30 km.
change the sensor and every thing was back to normal.
However, you could be right about the sensor thing. Normally electronic either work well or don't work at all. it seldom lose it performance gradually.
Wolverine, thanks for the HT cables again but I've not done anything with them just yet.
Fitting old cables is also one way of testing and altho it may quickly determine generally that the problems lie in the cables, it takes more time to identify which cable is causing the problem & then if not found in the first, I may have 5 other cables to test. :dunno:
So b4 I try ur cables, I hv first to try & c if the cables can b tested in an easier & more definitive way with quantitative data like from a diagnostics machine which used to be possible back in the '80s. From dis machine I could tell the running condition/ functioning of each cable compared to the rest.
So far I've not had a repeat of the same incident since we met last so I've not had a chance to try rapping the ignition control but thanx, now I kno what else to try/ test when I get into a situation.
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