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[BBBAD94ZR1]

I have a odd one here, every now and they when I start my car. Hook opened I can hear the plug arching on the right cylinder head area. I does it for arond 3 seconds and goes away, it does not affect the idle or engine perfomance. My wires are original and the plugs are new split fire triple electrodes. .50 gap. It only does this from what I can see at start up. The car runs fantastic otherwise.
Any ideas other than possilbly are wire going bad.
Your thoughts please.

RAY

[tomtom72]

I was thinking...I know bad idea...about that sound you hear Ray. It can't be a plug or a wire that is n/g or going bad because it would get worse the longer the motor runs...or at I would think that would happen.

If a plug archs to ground it's not gonna stop and if a wire is leaking voltage that don't stop either. Could the noise from the right side be the secondary vacuum pump? That runs for a bit upon start up to charge the secondary vacuum system and then shuts off...as long as the sys doesn't have any leaks.

Do you think you hear the chains before the oil PSI comes up? I know on my 90 I do but I think the later Z's don't have that noise because of a redesign on the tensioners, I think???

The only other thing I can think of that is on the right side is the alternator and the belt tensioner(serp belt) but I would think that if either made noise due to impending failure the noise would not stop.

Sorry I don't have a better answer to contribute. Maybe one of the senior guys has a direction to go in for you.

Tom

[BBBAD94ZR1]

It sounds exactly as if you pulled a wire off when the car is running and it starts to arch.
Ray

[tomtom72]

Hey Ray

I was thinking about the sound you're hearing and this thought wandered into my mind...Is it possible that you could hear the pintle in the injectors close? I would think that if it's possible for an injector to make a metallic noise from the pintle closing that it might sound like an electrical arc??

Just thought I'd toss that out to see what you think?


Tom

[We Gone]

Start touching plug wires while its running...If you have a leaker you'll find it.. ..Or start it up at nite you should see it..can you tell I'm from the old school...Good luck.

[BBBAD94ZR1]

TRIED THAT AND NOTHIN.
IT DOES NOT DO IT ALL THE TIME.
RAY

[Tom]

The air injection pump usually runs for a short time at startup and a leak in it's plumbing could be making noise.

If the sound occurs before the engine starts it could be the secondary vacuum pump but the secondary vacuum pump should shut off as soon as the engine starts since the engine pulls more than enough vacuum at idle to keep the secondary system happy. If you had a leak big enough to cause the vacuum pump to run with the engine at idle you would probably be setting trouble codes and have other idling and running problems.

I believe the shop manual states the only time the vacuum pump should run if the engine is running is when you stay at wide open throttle for extended periods, the rest of the time the engine pulls enough vacuum to keep the secondary system charged.

Does the engine run rough, cut out or miss?

I had a recent one that was doing that. You pull one of the plug wires off and the car died completely. Which should not happen. Closed off all ambient light and you could see arcing around the plug wires by the coil packs. And when pullingt he wire off, the spark wanted to ground by the dis module killing the vehicle.

Other things you could be hearing. Lifter noise, or injector noise.

[BBBAD94ZR1]

I will try looking in total darkness, it does not do it all the time kinD of seems like its corrected by the computer within seconds. Maybe Im JUST crazy..
RAY