missing 360
Thread Starter
|
New User
Joined: Nov 2012
Posts: 10
Likes: 0
missing 360
Hello fellow ford fans. I've browsed the forums and gained valuable info for the last few months, now I finally registered so I can ask some questions and get answers from experienced ford owners.
I have a '75 F250 4X4 highboy with the 360. Took off all the smog, and I put the heads and intake manifold (4 bbl) from my '65 on my highboy. Besides the head and intake swap, I also have an Edelbrock 600 cfm carb. The rest is stock. It was surprising what that little mod did for the power. Getting to my question, when the rpm's get just above 1000, it feels like it is missing. I've changed cap, rotor, plugs, wires. Did compression check and all cylinders are within 10-15 lbs. It runs smooth as silk at idle, but once it gets about 1200 rpm, it feels like a cylinder drops out. Any ideas?
I have a '75 F250 4X4 highboy with the 360. Took off all the smog, and I put the heads and intake manifold (4 bbl) from my '65 on my highboy. Besides the head and intake swap, I also have an Edelbrock 600 cfm carb. The rest is stock. It was surprising what that little mod did for the power. Getting to my question, when the rpm's get just above 1000, it feels like it is missing. I've changed cap, rotor, plugs, wires. Did compression check and all cylinders are within 10-15 lbs. It runs smooth as silk at idle, but once it gets about 1200 rpm, it feels like a cylinder drops out. Any ideas?
Thread Starter
|
New User
Joined: Nov 2012
Posts: 10
Likes: 0
Replaced the pump a couple years ago. I should probably check the fuel filter again, even though I changed that not to long ago. I bought the truck from a friend a few years ago and it had been sitting on his property for about seven years. There could be some gunk in the tank that is plugging up the filter. I appreciate the feedback.
Laughing Gas
Joined: May 2006
Posts: 1,140
Likes: 13
From: Port Orchard Wa
Have you checked the spark plug wires? I had a problem a couple of years ago. Truck would miss under acceleration/load. Tried all the usual suspects (new fuel pump, etc.). Then one day touched a plug wire and got zapped. Turned out the wire was not seated well on the plug. The weak spark would not fire when the fuel mixture got richer.
Trending Topics
Thread Starter
|
New User
Joined: Nov 2012
Posts: 10
Likes: 0
I was wondering about that myself. The plug wires I get now days for these motors never seem to fit quite right. They feel loose on the plug and, at least where I get them from, the boots on the two middle cylinders on each bank interfere with each other. I'm still not sure why it would only miss off idle and not all the time.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 59
Have you tried watching the engine at night or in the dark for spark arcing?
How advance are you running? I wouldn't go more than 12 degrees BTDC on a stock cam, and then set with the vacuum advance disconnected.
Also, you're using ported vacuum for the advance correct?
Josh
How advance are you running? I wouldn't go more than 12 degrees BTDC on a stock cam, and then set with the vacuum advance disconnected.
Also, you're using ported vacuum for the advance correct?
Josh
Thread Starter
|
New User
Joined: Nov 2012
Posts: 10
Likes: 0
Haven't looked at it in the dark. Good idea. I'm running 10 BTDC on ported vacuum. I've always been a firm believer that it's almost always the simplest solution. I've gone thru the basics, besides the tips you all have given, but I'm starting to think on a more general level. Are there mechanics that could be bad, i.e. lifter, balance etc.?
Thread Starter
|
New User
Joined: Nov 2012
Posts: 10
Likes: 0
Yes, I have the firing order correct. I think I need to reiterate that at idle, you can put your coffee on the air cleaner, and there wouldn't be a ripple in your cup. It runs perfectly smooth.
By the way, the three most powerful words, according to my girlfriend, are "three fifty two." The motor that's in my '65. She loves it when I pick her up in that truck. She actually requests to be picked up in the truck. How cool is that.
By the way, the three most powerful words, according to my girlfriend, are "three fifty two." The motor that's in my '65. She loves it when I pick her up in that truck. She actually requests to be picked up in the truck. How cool is that.
Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 59
As for mechanical:
Did you reinstall the pushrods back to there original positions? For hydraulic lifters there was a standard length depending on year, but post 68 is 9.59" with an over-under available of .060" (There were other over/unders avaible, but somewhat rare to find)
So installing a +60 PR in a lifter that needed a -60 you'll see you are now .120" tight.
Josh
Did you reinstall the pushrods back to there original positions? For hydraulic lifters there was a standard length depending on year, but post 68 is 9.59" with an over-under available of .060" (There were other over/unders avaible, but somewhat rare to find)
So installing a +60 PR in a lifter that needed a -60 you'll see you are now .120" tight.
Josh