Crackling under hood?
Thread Starter
Burning Brakes
Joined: Sep 2001
Posts: 1,011
Likes: 0
From: Jupiter Florida
Crackling under hood?
Recently my car started misfiring 2000-3000rpm immediately following a hard launch. This misfiring is accompanied by an intermittant crackling sound. After a few minutes the noise goes away and the misfire is gone until I push it hard again.
The wire jackets appear to be ok, but I did quickly look at them in the dark and noticed several places where I'm getting some very faint (not bright like a direct short) arcing. I recently had the opti apart, no dust/rust/whathaveyou so I'm disinclined to blame that, but I did clean up the the cap and rotor, so here's what I'm wondering;
Does it make sense that having a stronger spark would cause my (marginal?) wires and/or plugs to heat up under higher rpms and force the discharge to find a path of less resistance?
I've seen other posts about 'popping corn' under the hood, but wasn't able to find a conclusion. I'm just trying to get a feel for how disappointed I should expect to be if new plugs/wires don't fix the problem.
The wire jackets appear to be ok, but I did quickly look at them in the dark and noticed several places where I'm getting some very faint (not bright like a direct short) arcing. I recently had the opti apart, no dust/rust/whathaveyou so I'm disinclined to blame that, but I did clean up the the cap and rotor, so here's what I'm wondering;
Does it make sense that having a stronger spark would cause my (marginal?) wires and/or plugs to heat up under higher rpms and force the discharge to find a path of less resistance?
I've seen other posts about 'popping corn' under the hood, but wasn't able to find a conclusion. I'm just trying to get a feel for how disappointed I should expect to be if new plugs/wires don't fix the problem.
Pro
Joined: Jun 2001
Posts: 721
Likes: 10
From: Irvine CA
Re: Crackling under hood? (rocketfinger)
First impression is; if you can see arching, you need wires. I jut did the "dark room" thing with my car and found that the coil wire was bad.
If I remember my schooling properly, ignition problems show at low RPM and heavy acceleration. The increase in the cylinder head pressure increases the resistence of the mixture the spark must jump across. If you have a weak spot in the rest of the system the spark will ground, but not at the spark plug.
Plug wires, big PITA.
If I remember my schooling properly, ignition problems show at low RPM and heavy acceleration. The increase in the cylinder head pressure increases the resistence of the mixture the spark must jump across. If you have a weak spot in the rest of the system the spark will ground, but not at the spark plug.
Plug wires, big PITA.
Burning Brakes
Joined: Aug 2002
Posts: 848
Likes: 0
From: Houston TX
Re: Crackling under hood? (Yellow95)
It's actually normal to see the spark plug boot *glow* a little with each ignition event, while viewed in total darkness. The porcelain conducts a little light from combustion. But if you're seeing a *spark*, then the wires are bad.
Couldn't tell you what's causing the misfire/popping under hard acceleration - could be lots of things. Can you be more specific?
Couldn't tell you what's causing the misfire/popping under hard acceleration - could be lots of things. Can you be more specific?
