Discussion:
Clark CGC70L w/ Vortec V6

The unit was intermittently hard to start. It would crank with no problem just wouldn't start. While checking spark I noticed silver rub marks on the tops of the plug wires. The foil heat shield of the hood was coming loose and sitting on the wires. I fixed that but the engine still needs to cycle 4 to 5 time during start up before any spark is seen. Is this normal? The coil, wires, plugs, cap/rotor and regulator are all about 9 months old.
  • Posted 29 Sep 2010 22:33
  • By joe_d
  • joined 25 May'10 - 253 messages
  • Texas, United States
Ain't nothing I can't fix but a broken heart and the break of day!
Showing items 1 - 7 of 7 results.
Thanks for the info guys. This truck has been a thorn in my side with previous backfire issues, running rough and fluid leaks. Now, when I have operators complaining "Why does it take so long to get it started???", I start running for cover.
  • Posted 1 Oct 2010 21:05
  • By joe_d
  • joined 25 May'10 - 253 messages
  • Texas, United States
if as you say this is a tier2 C.A.R.B. truck, the engine may well be fitted with not only a crankshaft sensor that will want at least 1 complete engine revolution to be sure it sees the #1 cylinder ignition spot before it gets any spark, and may also have a low oil pressure shut off that would require a certain amount of oil pressure before it allowed a signal to the coil. Tier 2 trucks do NOT have or need the 0.5 (not 1.5 sec) sec time delay,
these are "good things".
This motor (as well as any other high compression motors with H.E.I.) can have a "rock-back" effect from the fact the motor always stops before T.D.C. on the compression stroke, and as soon as there is spark (key switch turned to on but not crank, micro second before key gets to crank position), if the motor's flywheel is not moving in the correct direction, that spark will cause the motor to turn in the opposite direction from the way the starter is just about to engage. To add to that, the way this starter mounts, and you may find more than expected breakage of the block near where the start mounts and the starter tearing nosecones. The delay, or waiting until the crank sensor has seen #1 T.D.C. 2 times, cures that problem.
As long as the motor has oil pressure, it doesn't wear the motor any more to turn at 150 rpm [starter cranking] than at 750 rpm, and unless you are using the very least expensive oil filters possible, then the engine should be able to pretty much get oil pressure within a few seconds cranking and it IS better to spin at slower speeds if you don't have full oil pressure. You may find better [as in more $] oil filters have a valve and spring to hold residual pressure when the engine is not turning, and not only to allow bypass when clogged.
starter wear is far more likely as a result of restarting each time the operator gets off the seat to scan a load than it will be from starting once with low oil pressure each day, but this -is- just one more spot where proper operator training can save lots of money, as well as changing the oil and filter at correct intervals and NOT using the least cost after market filters.
  • Posted 1 Oct 2010 20:11
  • Modified 1 Oct 2010 20:19 by poster
  • By edward_t
  • joined 5 Mar'08 - 2,334 messages
  • South Carolina, United States
"it's not rocket surgery"
the correct delay is 1.5sec. its under teh firewall cover, i believe on the RH side. but no, the delay module is needed to ensure the starter is fully engaged with the ring gear before the engine begins to fire, the consequences of kickback damage can be disastrous. at minimum, broken starter nosecones, and in extreme cases, engine block damage. do not disable the delay module. replace it if faulty.
  • Posted 1 Oct 2010 11:38
  • By steponmebbbboom
  • joined 21 Nov'05 - 189 messages
  • Ontario, Canada
Thanks, that would explain the 2 second or so delay. But, doesn't that make the starter go out sooner? More revolutions per actual start of engine?
  • Posted 1 Oct 2010 06:03
  • By joe_d
  • joined 25 May'10 - 253 messages
  • Texas, United States
It has been posted on this site that some of these engines are fitted with an ignition delay module to protect the starter motors. Could your ignition delay be from this?
  • Posted 1 Oct 2010 04:46
  • By AndyPandy
  • joined 26 Oct'07 - 175 messages
  • Staffordshire, WM, United Kingdom
Hello, Bruce. It's a tier 2 truck and I got all parts from the dealer including platinum plugs.
  • Posted 1 Oct 2010 02:48
  • By joe_d
  • joined 25 May'10 - 253 messages
  • Texas, United States
Ain't nothing I can't fix but a broken heart and the break of day!
joe,
is this a newer tier 2 or 3 truck? these engines call for Bosch platinum spark plugs for better starting. regular spark plugs just aren't hot enough.
  • Posted 1 Oct 2010 02:40
  • By bruce_c
  • joined 28 Jul'10 - 52 messages
  • Missouri, United States

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Fact of the week
The use of "hello" as a telephone greeting is attributed to Thomas Edison. He is said to have suggested it as a simpler alternative to other greetings, such as "Do I get you?" or "Are you there?".