Engine Ticking

[XfireZ51]

You may want to run the motor in total darkness. See if there is arching somewhere.

[Dmod81]

And that's the weird part- only one is dead.

I'll take a look in the dark tonight.

[Paul Workman]

Originally Posted by XfireZ51

You may want to run the motor in total darkness. See if there is arching somewhere.

I TOTALLY agree.^

Mice had nested on top of my coils, AND munched on a couple of the plug wires too. One wire was arching (as seen in total darkness), giving reason why only ONE plug was not firing in a "waste spark" situation. (Too bad too. The damaged wires were original with the roll-stamped with the LT5 lettering. I ended up selling or giving the rest away to someone needing a spare original (or two) for their NCRS car: same rodent issue.)

[A26B]

Although the LT5 is a paired cylinder/waste spark ignition, bad spark on a single cylinder can and has occurred on more than one instance, and resolved by a coil replacement. That being said, the problem is probably related to a coil terminal, bad coil internal connection to the terminal or corrosion since a winding breakdown would affect both cylinders.

I have not experienced the "dry plug wire boot misfire to ground" that Marc Haibeck has diagnosed and resolved. Several others here on the forum have had the problem and fixed it using Marc's recommendation, liberal application of silicone di-electric grease in the boot.

In that same vein of thought, I heartily recommend and use silicone dielectric grease on all electrical terminals and the weather seals in the connectors whenever the opportunity presents.

So, as previously stated; (1) check the spark to ground. orange = weak, blue with 3/4" gap jump = good coil & wire, (2) good spark & good plug with misfire may = need to grease the plug boot (3) if still missing after (1) & (2) check ok, replace the coil. I always save the most difficult and costly possibility until last.

[Dmod81]

Originally Posted by Paul Workman

I TOTALLY agree.^

After mice had nested on top of my coils, AND munched on a couple of the plug wires too. One wire was arching (as seen in total darkeness), giving reason why only ONE plug was not firing in a "waste spark" situation. (Too bad too. The damaged wires were original with the roll-stamped with the LT5 lettering. I ended up selling or giving the rest away to someone needing a spare original (or two) for their NCRS car: same rodent issue.)

Painful to lose nice wires like that.

Funny you mention rodents - I found signs of rodents in my garage last year. Never caught one, and haven't seen anything since. I checked the cars and bike, but didn't see any obvious issues. Maybe it did get the Z...

[Paul Workman]

Originally Posted by Dmod81

Painful to lose nice wires like that.

Funny you mention rodents - I found signs of rodents in my garage last year. Never caught one, and haven't seen anything since. I checked the cars and bike, but didn't see any obvious issues. Maybe it did get the Z...

Yeah, apparently the word got out to all of mousedome that LT5s have a nifty spot for nesting, judging by the frequency of times folks have found evidence of them nesting there...da sunzabitches!

[USAFPILOT]

mouse got in mine once, caught with a sticky trap

[Dmod81]

Just ran the car in the dark, nothing seen. Last time I changed the plugs, I filled the boots with dielectric grease, but I don't know what's on the coil ends. I'm going to start the plenum removal tomorrow.

[RICHARD TILL]

I replaced my coils with MSD`S last year due to no spark on #3 cylinder only. A month later i was pulling the plenum again. I`ll never pull it again without cleaning the contacts inside the starter solenoid.

[Dynomite]

Originally Posted by RICHARD TILL

I`ll never pull it again without cleaning the contacts inside the starter solenoid.

Great suggestion
Starter Rebuild

......and I might add........Never pull the Plenum without blocking TB Coolant at the Injector Housing

To accomplish that without removing the Injector Housings would require the removal of the Injector Housing Coolant Manifolds (use heat on those stubborn Coolant Manifold Bolts heating the Coolant Manifolds/Injector Housing in the area of each bolt). The Coolant Manifolds are removed to make sure you keep out aluminum shavings that may drop into each Injector Housing Coolant Port during installing of the TB Coolant Port threaded 1/8 inch pipe plug.

Injector Housing TB Coolant Blocking