Will detonation close a plug gap?
Thread Starter
|
Cargo Master
Joined: Apr 2004
Posts: 2,574
Likes: 4
From: Golden, CO
Interesting stuff fellas. How many of these were carbed, and how many were MPFI?
An interesting observation from work: Our first 0*f morning for the season and one of the stationary engines won't start. A few people try a few things and another says "get a torch and watch this". He pulls the plugs (they were fouled) and starts passing them through the heat zone at the end of the flame-where all the BTUs are. He never stopped in the heat, passed through maybe 6 or 8 times each to burn off the gas and carbon build up. Grant you that oxy-acetelene is hot, but at the 4th pass-through the ground electrode started to glow. By the time the porcelin was clean the ground was getting a pretty bright glow; close to plastic.
What impressed me is that it took seemingly very little heat to reach that point. I am wondering if this is one of the joys of MPFI. I have seen some pretty strange but impressive crap with MPFI, stuff that would not run if a carb were that far out of adjustment. One defective injector? One leaky intake runner? The ECU targets an average from one (or two) oxygen sensor(s), it is very possible for individual cylinders to have wacked-out A/F ratios. If a ground electrode were to get that hot, I wouldn't be surprised if it collapsed on it's own.
Just a few thoughts, Mike
An interesting observation from work: Our first 0*f morning for the season and one of the stationary engines won't start. A few people try a few things and another says "get a torch and watch this". He pulls the plugs (they were fouled) and starts passing them through the heat zone at the end of the flame-where all the BTUs are. He never stopped in the heat, passed through maybe 6 or 8 times each to burn off the gas and carbon build up. Grant you that oxy-acetelene is hot, but at the 4th pass-through the ground electrode started to glow. By the time the porcelin was clean the ground was getting a pretty bright glow; close to plastic.
What impressed me is that it took seemingly very little heat to reach that point. I am wondering if this is one of the joys of MPFI. I have seen some pretty strange but impressive crap with MPFI, stuff that would not run if a carb were that far out of adjustment. One defective injector? One leaky intake runner? The ECU targets an average from one (or two) oxygen sensor(s), it is very possible for individual cylinders to have wacked-out A/F ratios. If a ground electrode were to get that hot, I wouldn't be surprised if it collapsed on it's own.
Just a few thoughts, Mike
More Turbo
Joined: Nov 2004
Posts: 590
Likes: 1
From: in the woods of Maine!
well mine was a MPFI
and another thing, U have a misconceptiopn about O2 sensors.....the computer determines feul, but the coolant temp(motor temp), Intake Air Temp, Air flow(only if MAS system), Intake air Density, Barometric pressure outside.
it only uses the O2 to fine tune your feul trims(if OBD II), if OBD I, than you have no feul trim, but the O2 sensor still fine tunes the injector on-time(or the amount of feul the motor gets). a EFI car should run fine w/o an O2 sensor, or if it's unplugged, it just may run a little rich at times, and a little lean at others, but not enough to really tell....lol
O and on mine I know the piston is fine, because since my combustion chamber is a pentroof design, the plug is in the middle, like a hemi, and you can see the part of the piston RIGHT below the plug, and it all looked like new in there.....so I have no clue what could've done that to me!.....I know detonation couldn't have done that....it's impossible.....so I'm clueless....but I also won't loose any sleep over it!...lol
and another thing, U have a misconceptiopn about O2 sensors.....the computer determines feul, but the coolant temp(motor temp), Intake Air Temp, Air flow(only if MAS system), Intake air Density, Barometric pressure outside.
it only uses the O2 to fine tune your feul trims(if OBD II), if OBD I, than you have no feul trim, but the O2 sensor still fine tunes the injector on-time(or the amount of feul the motor gets). a EFI car should run fine w/o an O2 sensor, or if it's unplugged, it just may run a little rich at times, and a little lean at others, but not enough to really tell....lol
O and on mine I know the piston is fine, because since my combustion chamber is a pentroof design, the plug is in the middle, like a hemi, and you can see the part of the piston RIGHT below the plug, and it all looked like new in there.....so I have no clue what could've done that to me!.....I know detonation couldn't have done that....it's impossible.....so I'm clueless....but I also won't loose any sleep over it!...lol
Last edited by LedheadELH; Dec 9, 2006 at 04:56 PM.
Post Fiend
Joined: Sep 2006
Posts: 14,325
Likes: 14
From: Island Southeast Alaska
Originally Posted by 1975Ford
I tried the link, but it seems, he doing some work to the server now.
This happened once to me on a four cylinder, my commuter car.
I was driving home from work one day, and all of a sudden the engine starts to miss really bad. I'm like what s going on here.
The next day, I going thru the diagnostic checks, and start pulling spark plug wires and notice the number three cylinder had no change in idle when removed. I pull the spark plug, and sure enough, the side electrode is bent in all the way towards the center electrode. I shake my head in disbelief, I thinking something in the cylinder, slamming up and down, and now something is going to get damaged or ruin.
I decide to R&R the cylinder head and check what had fallen in the cylinder. Now I'm wondering what could this object in cylinder be?
I pull off the cylinder head, and look down the cylinder.
There was nothing in the cylinder. I just wanted to ease my mind and make sure nothing had fallen in. Replaced gaskets, and install new plug, everything ran perfect till the day I sold the car.
Could never figure what had caused this, maybe a foreign object in cylinder, or a weak side electrode.
This happened once to me on a four cylinder, my commuter car.
I was driving home from work one day, and all of a sudden the engine starts to miss really bad. I'm like what s going on here.
The next day, I going thru the diagnostic checks, and start pulling spark plug wires and notice the number three cylinder had no change in idle when removed. I pull the spark plug, and sure enough, the side electrode is bent in all the way towards the center electrode. I shake my head in disbelief, I thinking something in the cylinder, slamming up and down, and now something is going to get damaged or ruin.
I decide to R&R the cylinder head and check what had fallen in the cylinder. Now I'm wondering what could this object in cylinder be?
I pull off the cylinder head, and look down the cylinder.
There was nothing in the cylinder. I just wanted to ease my mind and make sure nothing had fallen in. Replaced gaskets, and install new plug, everything ran perfect till the day I sold the car.
Could never figure what had caused this, maybe a foreign object in cylinder, or a weak side electrode.
Post Fiend
Joined: Mar 2004
Posts: 6,056
Likes: 8
From: Union, Washington
Originally Posted by Hypoid
Interesting stuff fellas. How many of these were carbed, and how many were MPFI?
An interesting observation from work: Our first 0*f morning for the season and one of the stationary engines won't start. A few people try a few things and another says "get a torch and watch this". He pulls the plugs (they were fouled) and starts passing them through the heat zone at the end of the flame-where all the BTUs are. He never stopped in the heat, passed through maybe 6 or 8 times each to burn off the gas and carbon build up. Grant you that oxy-acetelene is hot, but at the 4th pass-through the ground electrode started to glow. By the time the porcelin was clean the ground was getting a pretty bright glow; close to plastic.
What impressed me is that it took seemingly very little heat to reach that point. I am wondering if this is one of the joys of MPFI. I have seen some pretty strange but impressive crap with MPFI, stuff that would not run if a carb were that far out of adjustment. One defective injector? One leaky intake runner? The ECU targets an average from one (or two) oxygen sensor(s), it is very possible for individual cylinders to have wacked-out A/F ratios. If a ground electrode were to get that hot, I wouldn't be surprised if it collapsed on it's own.
Just a few thoughts, Mike
An interesting observation from work: Our first 0*f morning for the season and one of the stationary engines won't start. A few people try a few things and another says "get a torch and watch this". He pulls the plugs (they were fouled) and starts passing them through the heat zone at the end of the flame-where all the BTUs are. He never stopped in the heat, passed through maybe 6 or 8 times each to burn off the gas and carbon build up. Grant you that oxy-acetelene is hot, but at the 4th pass-through the ground electrode started to glow. By the time the porcelin was clean the ground was getting a pretty bright glow; close to plastic.
What impressed me is that it took seemingly very little heat to reach that point. I am wondering if this is one of the joys of MPFI. I have seen some pretty strange but impressive crap with MPFI, stuff that would not run if a carb were that far out of adjustment. One defective injector? One leaky intake runner? The ECU targets an average from one (or two) oxygen sensor(s), it is very possible for individual cylinders to have wacked-out A/F ratios. If a ground electrode were to get that hot, I wouldn't be surprised if it collapsed on it's own.
Just a few thoughts, Mike
More Turbo
Joined: Nov 2004
Posts: 590
Likes: 1
From: in the woods of Maine!
That's a good point, never thought of that factor!
BTW, I read Hypoid's post a little backwards.lol, BUT, I still don't think a that must have been in rather good working order....it was a motor I JUST put together like 3 days prior....and all plugs were a nice light brown before and after this happened. I got some sensors that are bad, and possible ECU....so it doesn't start like it should, and I've trying to see if it's too rich, or too lean to start when cold???....but that's a whole other issue! lol
BTW, I read Hypoid's post a little backwards.lol, BUT, I still don't think a that must have been in rather good working order....it was a motor I JUST put together like 3 days prior....and all plugs were a nice light brown before and after this happened. I got some sensors that are bad, and possible ECU....so it doesn't start like it should, and I've trying to see if it's too rich, or too lean to start when cold???....but that's a whole other issue! lol
Last edited by LedheadELH; Dec 9, 2006 at 07:55 PM.
Thread
Thread Starter
Forum
Replies
Last Post
