Won't idle when warm.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Good videos. Hard to tell from here - in the first one though, the ignition timing sounds like it's off. The second one - what RPM? The gauge indicates according to the charts maybe intake leak, worn valve guides or sticky valve? But make sure ignition timing is set correctly and carb is adjusted right, I bet that will mimic other problems. Cylinder compression test check out OK?
Thread Starter
|
Freshman User
Joined: Aug 2017
Posts: 33
Likes: 0
I only had a little bit of time this evening and wanted to get the vacuum reading on video. Hopefully tomorrow I will check timing again and pull of the valve covers and take a look. I have never done a compression check but I'm not afraid to learn! I think I also definitely need to check sparks on each plug. Not sure if there is a misfire or if it's just associated with a leak somewhere.
Postmaster
Joined: Sep 2013
Posts: 2,595
Likes: 5
From: Pasadena, Ca
A compression check is like rebuilding a carb is like learning there is no Santa. Once you know, the magic and hype is gone and you will wonder by you believed it was so ooo la la in the first place.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Pull all the plugs, block the throttle open, make sure the battery is full charged. It's really the first test before anything else. Evilbay has some pretty decent deals. It ain't Snap-On but I bought one for less than $20, quality isn't bad for the price. Accurate enough.
Thread Starter
|
Freshman User
Joined: Aug 2017
Posts: 33
Likes: 0
Finally did the compression test and all cylinders had a reading between 120-130. And each reached full compression with only a couple cranks. I'm thinking about doing a leak down test next. I hooked the vacuum gauge up again because in the last video I had the timing advanced. With timing set to 12*, idle set to 850 the vac gauge has a sweep reading between 10 and 14 in/hg.
Lead Driver
Joined: Jul 2017
Posts: 9,600
Likes: 1,174
From: San Jose, CA
Strange that you would have that condition and still have some pretty good compression numbers though. Although I guess that's not impossible.
What was it reading with the timing advanced? And what was the timing at that point?
Since 12 degrees is actually a pretty nice setting for most engines, it's surprising (to me at least) that it ran good if it was anything more than say, 16 degrees BTDC. At that point my engine would have been pinging like a big dog under any acceleration.
If it ran better and had higher vacuum numbers (nearer to 18-21?) when the timing was more advanced, I wonder if the timing marks are off a bit.
Anyway, I'll re-read the last few pages to see what I missed.
Paul
What was it reading with the timing advanced? And what was the timing at that point?
Since 12 degrees is actually a pretty nice setting for most engines, it's surprising (to me at least) that it ran good if it was anything more than say, 16 degrees BTDC. At that point my engine would have been pinging like a big dog under any acceleration.
If it ran better and had higher vacuum numbers (nearer to 18-21?) when the timing was more advanced, I wonder if the timing marks are off a bit.
Anyway, I'll re-read the last few pages to see what I missed.
Paul
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Keep and maintain idle RPM around 550-650 and advance distributor for maximum steady manifold vacuum on the gauge. Should be 18" to 20" on a healthy stock motor. Lean out the carburetor mixture screws for maximum vacuum as well. May have to go back and forth a couple times as they interact with each other.
As a kind of verification test - then see what the timing is at indicated on the damper. It does sound a little like the marks might be buggered, tough to tell from here.
As a kind of verification test - then see what the timing is at indicated on the damper. It does sound a little like the marks might be buggered, tough to tell from here.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Did the engine spend a lot of time over the years sitting in a field inoperable or anything like that? Sludge and varnished fuel will tend to stick rings and valve lifters &c.
Replace 1qt of crankcase oil with Marvel's Mystery Oil. Install 4oz. of same for each 10 gallons of fuel in the gas tank. Both fuel and oil.
Then make a highway run or two, drive normally get it warmed up etc. It's a mild solvent with penetrating oil (wintergreen) and is just the stuff for freeing up valve lifters and stuck rings. Worth a try and usually works fast.
Replace 1qt of crankcase oil with Marvel's Mystery Oil. Install 4oz. of same for each 10 gallons of fuel in the gas tank. Both fuel and oil.
Then make a highway run or two, drive normally get it warmed up etc. It's a mild solvent with penetrating oil (wintergreen) and is just the stuff for freeing up valve lifters and stuck rings. Worth a try and usually works fast.
Thread Starter
|
Freshman User
Joined: Aug 2017
Posts: 33
Likes: 0
I have bee thinking of using seafoam or MMO. What is the best between the two and if you have used them, some say to let some through the brake booster vac into the intake? Is this common practice?
Lead Driver
Joined: Jul 2017
Posts: 9,600
Likes: 1,174
From: San Jose, CA
But I'm still a big fan of cleaning additives even after using them for almost 50 years. Because for me at least, they've almost all worked as expected.
And the ones that did not could just have been due to the severity of the problem more than any lack of chemical prowess.
You'll have one VERY clean cylinder!
It's probably one of the easier vacuum lines to access, but verify it's source.
Easier still would be the PCV vacuum line on any engine from the early sixties on up. They are all supposed to be plumbed to the common plenum, so are a better choice.
But just like the other one, verify it's source. Plenty of them out there that have been connected incorrectly.
Paul
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Don't pour it down the intake don't pour it down the spark plug holes don't suck it through a vacuum hose.
Just put it in the gas AND crankcase per the directions on the can. I've heard good things about Seafoam too, but I don't have any experience with that. I know for a fact MMO works for this purpose so mentioned it. If it doesn't work you're out 5 bucks, it can't hurt anything and may help.
Just put it in the gas AND crankcase per the directions on the can. I've heard good things about Seafoam too, but I don't have any experience with that. I know for a fact MMO works for this purpose so mentioned it. If it doesn't work you're out 5 bucks, it can't hurt anything and may help.