79 400m runing right issues
Elder User
Joined: Dec 2007
Posts: 813
Likes: 6
From: Up Nort Minnesota
have you rebuilt the carb? it isn't just an accelrator pump diaphram gone bad is it?
with the motor not running if you look down the carb throat with a flashlight & pull the throttle back by hand do you see the squirt gun streams of gas from the accelerator pump?
with the motor not running if you look down the carb throat with a flashlight & pull the throttle back by hand do you see the squirt gun streams of gas from the accelerator pump?
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 106
Likes: 0
From: belton mo
no i havnt done a vac test..
and i tried a different carb still same thing.. the carb does smoke for a little bit after i turn off the truck.. like its still got gas down there..
and i tried a different carb still same thing.. the carb does smoke for a little bit after i turn off the truck.. like its still got gas down there..
Elder User
Joined: Jan 2004
Posts: 887
Likes: 0
From: Colorado
Have you ever had the distributor completely out of the block?? I had similar problems, and it ended up being thta the distributor roll pin had sheared, and turned the gear on the dizzy shaft a few degrees to where it idled fine but didnt do anything for power. Try another distributor!!
Zombie Survivalist
Joined: Feb 2009
Posts: 14,809
Likes: 3
From: Rock Springs, WY, USA
i just got done reading a deal about 400Ms. they came from the factory with emissions in mind and made like 175 hp. this was because they came from the factory with the cam retarded 6 degrees. the one they did a rebuild on made 65 hp on the dyno. they did a rebuild for less than $2000 and made 385 hp and 475 ftlbs of torque. naturally i cant find the article now, but it also said that the cam had like 6 flat lobes when they first took it apart for the build.
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
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 106
Likes: 0
From: belton mo
ok well i tried a few things today.. i just messed with the carb a little sprayed wd40 around the intake seals and no change in idle or anything havnt messed with the fuel pump yet.. i just reved it all the way and let it roar for about 3-6 seconds and it sounded good to me.. just some smoke came out the pipe.. now in drive it still idles rough but when drive it down the road seems to have a little more power... im stumped?..
Zombie Survivalist
Joined: Feb 2009
Posts: 14,809
Likes: 3
From: Rock Springs, WY, USA
get on the highway in a low gear and let that puppy scream. just drive it that way for 10 min or so. get the carbon blown out. stop at napa and get some sea foam and add that. sounds to me like youve just got carbon buildup issues. use the "add to intake" directions. the tons of white smoke it will make is NORMAL. do it outside.
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Is your vacuum advance working? do you have it connected to ported or manifold vacuum?
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Which port? above or below the throttle blades? above the blades pulls ported vacuum and below the blades pulls manifold vacuum, if you're connected to the latter then you're pulling in all your vacuum advance at idle which would create an off idle stumble and lack of acceleration like you've described.
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 106
Likes: 0
From: belton mo
its connected to the carb in the front its really low on the carb.. it idles great.. but in drive idle crappy and doesnt really want to accerlate.. im gonna run it in low gear down the road tomorrow see if that helps but it does a little better off the start now but after about 1/8 of the throttle there is basically no power ..