I-Talian Tune UP

Old60Driver · Jun 15, 2021

So, I had gotten ye old '83 running pretty decent. Driving her everyday, 13 miles each way to work. Getting a little heat soak after about 15 minutes when I'd run into the grocery store, but nothing I couldn't live with.

Three days ago, I noticed she wasn't running at optimum. Seemed like a bit of a miss. Not so much at first startup in the morning, but as she warmed up, I noticed it when I'd pull up to a light. She ran great off idle, but AT idle in gear? Not so good. It progressively got worse; I was sure I had a fouled plug. I kept bumping up her idle screw just to keep her going because she was shaking at the stops. Never felt like she was going to die, and would take off great, but I knew something was wrong. Today was the first time I'd had to actually wrench on her, and I thought I'd share.

I checked everything I could think of. Pulled the plugs, they looked about as perfect as I'd ever seen. Checked for vacuum leaks. Nope. Checked timing (maybe I didn't have the lockdown tight enough?) Nope. Checked fuel filter. Nope. Pulled the dizzy cap. All was good in there. I couldn't figure it out, but I felt it was in the idle circuit, because she ran so well at RPM.

Decided to try the whole 'I'll run the RPM up while choking her with my hand, and see if maybe I can unplug something' routine that my dad showed me so many years ago. THAT made a bit of difference. Not a ton, but I gained a hundred RPM at idle.

I was just staring at her while she idled, and saw a can of Seafoam I had in my toolbox. I've been running a can every two tanks or so because she sat so long. Anyway, I poured about half the can down her gullet, while keeping her running. Didn't seem to make a big difference, so I flooded her out with a good portion of what was left, and let her sit for a bit while I replaced my temperature sending unit out.

Long story short, when I fired her back up, I expected a bunch of smoke (I'd been down this road before lol), but what I didn't expect was for her to be idling at 1100 RPM, and just PURRING!!!

No misses, no stumbles, NADA! I brought the idle down to 700 or so, and man, she sounds and drives great!!! Decided to reward her with a bath and a cruise down the country roads around town. Damn fine time.

Here's the question:
WHY did it fix it? I mean, she's idling better than she EVER has. Granted, I've only been messing with her about 5 weeks after sitting for several years, but still. She idles as smooth as my 2019 DD.

Was there simply a blockage in the idle circuit? Could the 'top end cleaning' thing be real?

Anyway, I'd love to hear y'alls thoughts, and thanks for reading!

Gotta run to town for some cold snacks. Yep, I'll be taking the long way.

Catbox · Jun 15, 2021

Definitely a VGG fan.

I suspect there may have been some buildup on the valves where they seal to the seat that may have been cleaned off from the Seafoam.

Bextreme04 · Jun 15, 2021

That would be my guess too. You probably had a rough idle due to a compression leakage from a leaky valve. Good heatsoak with the seafoam probably cleaned off whatever was stuck to the valve seat or maybe seat a piston ring. My truck had always had a miss and ran rough with a difficult time idling low. It wasn't until it blew up that I found the cylinder that had always had low compression and misfire issues had both compression rings broken into 20 pieces or so.

78C10BigTen · Jun 15, 2021

Old60Driver said:
So, I had gotten ye old '83 running pretty decent. Driving her everyday, 13 miles each way to work. Getting a little heat soak after about 15 minutes when I'd run into the grocery store, but nothing I couldn't live with.

Three days ago, I noticed she wasn't running at optimum. Seemed like a bit of a miss. Not so much at first startup in the morning, but as she warmed up, I noticed it when I'd pull up to a light. She ran great off idle, but AT idle in gear? Not so good. It progressively got worse; I was sure I had a fouled plug. I kept bumping up her idle screw just to keep her going because she was shaking at the stops. Never felt like she was going to die, and would take off great, but I knew something was wrong. Today was the first time I'd had to actually wrench on her, and I thought I'd share.

I checked everything I could think of. Pulled the plugs, they looked about as perfect as I'd ever seen. Checked for vacuum leaks. Nope. Checked timing (maybe I didn't have the lockdown tight enough?) Nope. Checked fuel filter. Nope. Pulled the dizzy cap. All was good in there. I couldn't figure it out, but I felt it was in the idle circuit, because she ran so well at RPM.

Decided to try the whole 'I'll run the RPM up while choking her with my hand, and see if maybe I can unplug something' routine that my dad showed me so many years ago. THAT made a bit of difference. Not a ton, but I gained a hundred RPM at idle.

I was just staring at her while she idled, and saw a can of Seafoam I had in my toolbox. I've been running a can every two tanks or so because she sat so long. Anyway, I poured about half the can down her gullet, while keeping her running. Didn't seem to make a big difference, so I flooded her out with a good portion of what was left, and let her sit for a bit while I replaced my temperature sending unit out.

Long story short, when I fired her back up, I expected a bunch of smoke (I'd been down this road before lol), but what I didn't expect was for her to be idling at 1100 RPM, and just PURRING!!!

No misses, no stumbles, NADA! I brought the idle down to 700 or so, and man, she sounds and drives great!!! Decided to reward her with a bath and a cruise down the country roads around town. Damn fine time.

Here's the question:
WHY did it fix it? I mean, she's idling better than she EVER has. Granted, I've only been messing with her about 5 weeks after sitting for several years, but still. She idles as smooth as my 2019 DD.

Was there simply a blockage in the idle circuit? Could the 'top end cleaning' thing be real?

Anyway, I'd love to hear y'alls thoughts, and thanks for reading!

Gotta run to town for some cold snacks. Yep, I'll be taking the long way.

This title immediately made me laugh! My dad used do this in his 73 c10 while cruisin down the road... hed look at me, reach down and grab the choke and say its time for the "buck fifty" tune up lol

Old60Driver · Jun 15, 2021

78C10BigTen said:
This title immediately made me laugh! My dad used do this in his 73 c10 while cruisin down the road... hed look at me, reach down and grab the choke and say its time for the "buck fifty" tune up lol

Holy hell!! BUCK FIFTY TUNE UP!!! Awesome!! Totally stealin' this! :cheers:

Old60Driver · Jun 15, 2021

Catbox said:
Definitely a VGG fan.

I suspect there may have been some buildup on the valves where they seal to the seat that may have been cleaned off from the Seafoam.

Roger that. I was kinda thinking the same thing, but needed some backup! lol

I've done quite a few Seafoam heatsoaks, but never had results like this. Ain't complain' though.

Hitting the road for a 10 hour road trip tomorrow at 0200. Wish me luck!

78C10BigTen · Jun 15, 2021

Old60Driver said:
Holy hell!! BUCK FIFTY TUNE UP!!! Awesome!! Totally stealin' this!

That was back in the late 90s lol. The truck i learned to drive in! (Still in my moms yard, and runs!) :happy160:

rpcraft · Jun 15, 2021

Sitting is the worst thing that can happen to older vehicles. Crap in the fuel, lines, filters, etc etc, just makes it's way into the carb and elsewhere. Ethanol makes things worse. If you do not run a motor that has had older types of oils in it and was perhaps not changed often then it is easy for the sludge to stick to the valves, valve faces, piston faces, etc etc and as the engine cools it turns into tar and eventually hardens and makes stuff stick or wipes bearings and rollers. The italian tune-up helps because the idea is you are going out and warming the motor up and then providing it runs well enough you are running the engine at it's max peak efficiency, which means making power. It blows out the crap to some degree.

Camar068 · Jun 15, 2021

love seeing seafoam fixes.....I just love the stuff. Of topic but I thought my weedeater was gonna blow up it was idling so high after 2 cap fulls in the tank lol. Just one example.

Goldie Driver · Jun 15, 2021

78C10BigTen said:
This title immediately made me laugh! My dad used do this in his 73 c10 while cruisin down the road... hed look at me, reach down and grab the choke and say its time for the "buck fifty" tune up lol

My Dad always said he needed to "Blow the carbon out ".

Same idea - some excuse to flog it.

rpcraft · Jun 16, 2021

Camar068 said:
love seeing seafoam fixes.....I just love the stuff. Of topic but I thought my weedeater was gonna blow up it was idling so high after 2 cap fulls in the tank lol. Just one example.

Seafoam isn't good for cleaning carbs or trash out of gas tanks. You know what is? Actually taking the stuff apart and physically cleaning them. I see guys on bikes all the time talk about use some seafoam, then weeks later they'll post again talking about how their bike still runs like crap.

Duh....

At best seafoam is decent for cleaning some parts in the valve train and top of the piston because of the steaming action, but then again so is water if you know what to do and how to apply through the carb, otherwise get some fuel injection cleaner and follow the steps for FI setups.

gotyourgoat · Jun 16, 2021

Goldie Driver said:
My Dad always said he needed to "Blow the carbon out ".

Same idea - some excuse to flog it.

Haha I have that same memory. Blowing the carbon out. Great excuse to drop the hammer. It's a tradition I'd like to keep alive. :burnout:

Octane · Jun 16, 2021

rpcraft said:
Seafoam isn't good for cleaning carbs or trash out of gas tanks. You know what is? Actually taking the stuff apart and physically cleaning them. I see guys on bikes all the time talk about use some seafoam, then weeks later they'll post again talking about how their bike still runs like crap.

Duh....

At best seafoam is decent for cleaning some parts in the valve train and top of the piston because of the steaming action, but then again so is water if you know what to do and how to apply through the carb, otherwise get some fuel injection cleaner and follow the steps for FI setups.

And it's amazing what a two day carb soak can do in a gallon can of carb parts cleaner.And also the compressed air.Just rebuilt my 44 year old carb for the first time since it was new.That dirty idle circuit can be a problem.

oldretiredafguy · Jun 16, 2021

Seafoam=an apple a day keeps the doctor away.

DoubleDingo · Jun 16, 2021

rpcraft said:
Seafoam isn't good for cleaning carbs or trash out of gas tanks. You know what is? Actually taking the stuff apart and physically cleaning them. I see guys on bikes all the time talk about use some seafoam, then weeks later they'll post again talking about how their bike still runs like crap.

Duh....

At best seafoam is decent for cleaning some parts in the valve train and top of the piston because of the steaming action, but then again so is water if you know what to do and how to apply through the carb, otherwise get some fuel injection cleaner and follow the steps for FI setups.

Motor Purr works, though. I use it in my chain saw, lawn mower, vehicles. Chain saw won't start. Add some motor purr to the fuel, let it sit for a day, go to start it and it will start. Lawn mower sits with gas in the tank, add some motor purr to the tank before the first start of the season, and one pull, it starts. No issues with anything gummed-up. Old Tecumseh-power rototiller from Western Auto, that dates it to at least the 60s or 70s, and same thing, motor purr de-gums the fuel system very effectively. Of course finding motor purr is the biggest challenge.

I-Talian Tune UP

Old60Driver

1983 K20 Silverado

Catbox

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Bextreme04

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78C10BigTen

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Old60Driver

1983 K20 Silverado

Old60Driver

1983 K20 Silverado

78C10BigTen

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rpcraft

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Camar068

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Goldie Driver

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rpcraft

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gotyourgoat

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