spark plug evaluation - help - timing? running temp?

[Jwernatl]

Guys - I have an 87' Long Bed 4WD Silverado bone stock - 350 TBI W/700R4-


I replaced my plugs last night and they looked VERY ODD to me. There is a dark side and light side - Very prominent and it was on EVERY plug -


Here I uploaded videos. But pics are also attached

https://www.dropbox.com/sh/eh82mt6slwu29vs/AACEnV7IgmmKcK4pFU3jzTEba?dl=0

Would the timing have something to with
1. lack of power?
2. with the truck temp running low?
3. the odd looking burn on spark plug?


Here's a little back info....

When I bought the truck(Sept 2020), it had been siting for since 2003 - (Original owner replaced the drivers side Fuel tank prior to me picking the truck up)

After driving it for a few days, occasionally, it would stall when slowly coming to a stop - after it would stall, I'd drop it in park - turn the key and it started back up EVERY-TIME and continue to idle perfect.

So far I've completed the following...
1. swapped ALL fluids (complete - front to back- power steering to rear diff)
a. new 180 degree thermostat
b. replaced all the vacuum lines.
2. plugs, wires, distributor, etc.
3. replaced the passenger side fuel tank w/ accessories - pump, fuel lines etc...
4. Replaced the TBI w/a Holley® p/n 502-6 (670 CFM Two Barrel TBI) (included MAP and IAC) - the truck stopped stalling after replacing the TBI.


***

Last week I took a trip to Alabama, and pulled my HARLEY on the trailer -

1. After pulling a trailer on interstate - I don't think I have as much power As I should -
2. My truck was not getting much over 160 degrees (had 180 degree thermostat installed).

AND SO -- Last night,

I swapped spark plugs to ACDELCO 41-803 gapped @ .035 and switched to a 195 degrees thermostat
I pulled the advance connector and checked the timing -

With the truck warmed up approx 180 and RPM @ idle (approx 780) the TIMING shows 0 DEGREES - (actually my timing-mark light is approx the width of a nickel to the right of the of the 0 degrees mark)

Where should timing be?
Can anyone tell me about the burn on the spark plugs? please see attached video and pics below ...

Again, I'd like to hear opinions - Would the timing have something to with
1. lack of power?
2. With the truck temp running low?
3. is the burn on spark plug normal? if not, because of timing?

Sorry this is so long, I wanted to give as much info as I could - thank you all for your patience.

 

[Bextreme04]

Guys - I have an 87' Long Bed 4WD Silverado bone stock - 350 TBI W/700R4-


I replaced my plugs last night and they looked VERY ODD to me. There is a dark side and light side - Very prominent and it was on EVERY plug -


Here I uploaded videos. But pics are also attached

https://www.dropbox.com/sh/eh82mt6slwu29vs/AACEnV7IgmmKcK4pFU3jzTEba?dl=0

Would the timing have something to with
1. lack of power?
2. with the truck temp running low?
3. the odd looking burn on spark plug?


Here's a little back info....

When I bought the truck(Sept 2020), it had been siting for since 2003 - (Original owner replaced the drivers side Fuel tank prior to me picking the truck up)

After driving it for a few days, occasionally, it would stall when slowly coming to a stop - after it would stall, I'd drop it in park - turn the key and it started back up EVERY-TIME and continue to idle perfect.

So far I've completed the following...
1. swapped ALL fluids (complete - front to back- power steering to rear diff)
a. new 180 degree thermostat
b. replaced all the vacuum lines.
2. plugs, wires, distributor, etc.
3. replaced the passenger side fuel tank w/ accessories - pump, fuel lines etc...
4. Replaced the TBI w/a Holley® p/n 502-6 (670 CFM Two Barrel TBI) (included MAP and IAC) - the truck stopped stalling after replacing the TBI.


***

Last week I took a trip to Alabama, and pulled my HARLEY on the trailer -

1. After pulling a trailer on interstate - I don't think I have as much power As I should -
2. My truck was not getting much over 160 degrees (had 180 degree thermostat installed).

AND SO -- Last night,

I swapped spark plugs to ACDELCO 41-803 gapped @ .035 and switched to a 195 degrees thermostat
I pulled the advance connector and checked the timing -

With the truck warmed up approx 180 and RPM @ idle (approx 780) the TIMING shows 0 DEGREES - (actually my timing-mark light is approx the width of a nickel to the right of the of the 0 degrees mark)

Where should timing be?
Can anyone tell me about the burn on the spark plugs? please see attached video and pics below ...

Again, I'd like to hear opinions - Would the timing have something to with
1. lack of power?
2. With the truck temp running low?
3. is the burn on spark plug normal? if not, because of timing?

Sorry this is so long, I wanted to give as much info as I could - thank you all for your patience.

Seems to be running colder than I would expect it to. The plugs look very good. Did you set the Idle with the new TBi unit? Did you set the timing? I believe you are supposed to set the timing, on a fully warmed engine, to zero with the brown w/black stripe wire in the passenger side of the engine bay disconnected. When you plug it back in it should show some intial timing at idle(I would expect 4-12 deg advanced at idle). If that isn't what you are seeing you might have a distributor issue, an ECU issue, or maybe a knock issue that is causing the motor to pull timing advance.

 

[Jwernatl]

Bextreme04- thank you for the reply....

"Seems to be running colder than I would expect it to"
I agree, its running colder than it should -

"The plugs look very good"
even being burned on one side?


"Did you set the Idle with the new TBi unit?"
I didnt set the idle - it was where it is now.


"I believe you are supposed to set the timing, on a fully warmed engine, to zero with the brown w/black stripe wire in the passenger side of the engine bay disconnected."
The timing is set at zero degrees. (*Actually, just right of the zero mark)

"Did you set the timing?"
The timing was set already - I checked it with engine as warm.- (I unplugged the advance brown w/black stripe wire - Mine is on the drivers side, up by fire wall.


"When you plug it back in it should show some intial timing at idle(I would expect 4-12 deg advanced at idle)."
When I plugged the advance brown w/black stripe wire back in - it jumped about 20 degrees -

You are seeing you might have a distributor issue, an ECU issue, or maybe a knock issue that is causing the motor to pull timing advance.
How should I determine? HMMM.....

 

[Bextreme04]

I would recommend you go through the idle set procedure. Its possible that the gauge sending unit is just off and you are actually getting up to the right temp. The plugs don't look burnt to me, it looks like deposits from combustion to me. The chambers aren't balanced, so it makes sense that it would be more built up on one side more than the other.

So you are saying that the Zero-ish reading was taken with the advance wire disconnected? That is the desired setting, although it sounds like the timing is actually retarded a bit. You should probably adjust it to either zero or a few degrees advanced(counter-clockwise) of zero. When you plugged it in and it jumped about 20 deg, did it jump counter-clockwise that amount?

Did you check for any ECU fault codes?

You can see all of the engine parameters with an ALDL cable and some computer software or phone apps.

 

[AuroraGirl]

Seems to be running colder than I would expect it to. The plugs look very good. Did you set the Idle with the new TBi unit? Did you set the timing? I believe you are supposed to set the timing, on a fully warmed engine, to zero with the brown w/black stripe wire in the passenger side of the engine bay disconnected. When you plug it back in it should show some intial timing at idle(I would expect 4-12 deg advanced at idle). If that isn't what you are seeing you might have a distributor issue, an ECU issue, or maybe a knock issue that is causing the motor to pull timing advance.

Or ive heard from guys with these and slightly newer small blocks, knock issues or perceived knock issues can really throw a wrench in the diagnosis.
Something about using a newer style sensor and making sure exhaust ground-outs dont occur and mounts are good?

 

[Rusty Nail]

Screw zero degrees at idle dude...many if.not most squarebodies I ever seen are only tuned well enough to run 6-10° with that wire unplugged? Zero is the factory setting of 30 years ago! That's why your truck is so slow ... it's choked out at 180 and I think your plugs may be the wrong heat range?

I run Delco R45TS plugs at TWELVE degrees. ..

The exhaust valve is on the dark side..

You must be registered for see images attach

I bet if you made a couple of tweaks it would come back around?...can we double check those spark plugs please?
Chances are it will NEVER tune correctly with a 180° stat - in stock trim. Especially if the plugs are too cold or short.

xc_hide_links_from_guests_guests_error_hide_media

*edit*
I'm gonna hang up pretty hard on the strange plugs. I never heard that number in my life...

• AC Delco 41-803 replacement spark plugs
• Autolite APP25
• Denso 4510
• Denso 5331
• Denso ITF20
• Denso PTF20TT

** edit part duex

Dude... arent Autolite hotter at lower number? If you run autolite in a cheby aint it the 21? Not the 25? Delco get hotter as the number gets higher.. a 45 is hot, a 41 cold . But what is a.p.p mean? I dunno! Autolites r 4 fords. I thought denso was in hondas so why is that number found when looking up those weirdo 41-803 plugs?
What I know about Delco plugs says you want a 45-803? Is that such a thing or? 41-805? 41 is the reach yes?

 

[Rusty Nail]

Yes.

Oh wait...hey're double platinum?

That might be your problem...

you got the wrong spark plugs.

Your truck is thirty years old and likes conventional plugs pliz. I bet the correct part is Delco R44TS.

xc_hide_links_from_guests_guests_error_hide_media

 

[AuroraGirl]

Yes.

Oh wait...hey're double platinum?

That might be your problem...

you got the wrong spark plugs.

Your truck is thirty years old and likes conventional plugs pliz. I bet the correct part is Delco R44TS.

xc_hide_links_from_guests_guests_error_hide_media

You’re saying to use r44 because of not running a truck In the exact factory setup means it’s probably needing that instead of the r45 it calls for? I’m just wondering what you mean.

To my understanding, more compression(usually also heat in turn) you want a hotter plug to reduce likelihood of knock or pre ignition generally, but a colder than necessary plug is more likely to foul the plugs and leave deposits In the combustion chamber.
Meaning you need to find a plug that keeps your cylinder from being too hot and pigmy but not keep it dirty and fouly

is this correct?

a low compression engine smogged up may want a colder plug but a low compresssion engine with a higher t stat or some hp adding/not power robbing enhancements wants a hotter plug. Ac delco plugs increasingly by counting down?
And hotter ignition liking smaller gaps as well, separate this

 

[Rusty Nail]

You're fun Auroragirl! That sure covers a lot of ground...you can hear the buttholes puckerin cant ya?
Tricky to answer all if that but basically;

Spark plug "heat range" for the sake of this discussion, is more appropiately a measurement of time or it's actually camshaft duration - rather than temperature.

Those numbers represent - how long the spark plug actually fires. Hotter plugs fire longer than colder plugs.. the letters represent a measurement of reach into the combustion chamber.?

Aluminum wants different than iron, CC, quench, head design , operating temps, all that comes into play and sometines when people try new tech into old tech the results are often undesireable, and we have all seen that here and other threads in this msb.

Not to fault the OP but I dont know him - I believe he got sold is all. Same kind of schtick mechanics pull on unknowing women, thats the ploy for men at double the price kind of deal - if you get what im sayin. Surely the fancy new plugs will be worth the cost, right?
Know your enemy. Maybe a different source for parts would be better.

I have said this before and stand on it, often fancy platinum type plugs cannot reach their self-cleaning temperature before they foul - especially in older or higher mileage engines with looser internal tolerances and richer fuel mixtures. Especially in a wet manifold!

The darkside represents an incomplete burn. You can see the ash on the plugs!


Commence the bashfest . Look im not a pro but I used to know a little bit about it and this is common.

 

[AuroraGirl]

You're fun Auroragirl! That sure covers a lot of ground...you can hear the buttholes puckerin cant ya?
Tricky to answer all if that but basically;

Spark plug "heat range" for the sake of this discussion, is more appropiately a measurement of time or it's actually camshaft duration - rather than temperature.

Those numbers represent - how long the spark plug actually fires. Hotter plugs fire longer than colder plugs.. the letters represent a measurement of reach into the combustion chamber.?

Aluminum wants different than iron, CC, quench, head design , operating temps, all that comes into play and sometines when people try new tech into old tech the results are often undesireable, and we have all seen that here and other threads in this msb.

Not to fault the OP but I dont know him - I believe he got sold is all. Same kind of schtick mechanics pull on unknowing women, thats the ploy for men at double the price kind of deal - if you get what im sayin. Surely the fancy new plugs will be worth the cost, right?
Know your enemy. Maybe a different source for parts would be better.

I have said this before and stand on it, often fancy platinum type plugs cannot reach their self-cleaning temperature before they foul - especially in older or higher mileage engines with looser internal tolerances and richer fuel mixtures. Especially in a wet manifold!

The darkside represents an incomplete burn. You can see the ash on the plugs!


Commence the bashfest . Look im not a pro but I used to know a little bit about it and this is common.

Not the same engine but here’s an iridium plug less than a day old

You must be registered for see images attach

3800 series 2. Even has free cocaine on the insulator.

I only ever use copper plugs on anything other than my Buick which is using iridium. Platinum has been a no no for me because price for a plug was too high or I planned on frequent plug changes/it was easier than dirt(my old Saturn. My Hyundai. Sbc in my square. ) ever since I got a m12 ratchet starting a plug and doing most work with that has been nice.

my square has black plugs but it doesn’t see any road time so poor guys can’t clean. Also ignitions systems generally weaken with age and copper is a great cheap conductor. My k series Koehler committed coil suicide only after homicide against the points and condenser I just put on when I used 2 non solid copper core wires.. forums say the coil can’t handle modern spiral carbony fun

 

[Rusty Nail]

I spent a minute readin about spark plugs tonight. R (in R45TS) stands for "resistor".
Ok.
Then there's lots to learn about...AM radios in cars...radio interference was real problem without resistor plugs - invented to kill the interference but switched to FM anyways because
Enter WW2 and the FCC..then I realized my studies had gone off topic, like this thread, but then I was like.

Whatever.

 

[Octane]

Delete

 

[AuroraGirl]

I spent a minute readin about spark plugs tonight. R (in R45TS) stands for "resistor".
Ok.
Then there's lots to learn about...AM radios in cars...radio interference was real problem without resistor plugs - invented to kill the interference but switched to FM anyways because
Enter WW2 and the FCC..then I realized my studies had gone off topic, like this thread, but then I was like.

Whatever.

i do the same
we are not so different, you and I

does that frighten you?

 

[Octane]

i do the same
we are not so different, you and I

does that frighten you?

Frightens me tho. Lol

 

[Octane]

FCC rules changed in the 1970s requiring am and fm band radio combos. Prior to this the radio in my dads car was an 8 track am radio combo.Fm converters were offered also in the 70s to add fm to your am radio.And I remember the noisy old radios