is it carb or timing issues?
Thread Starter
|
Senior User
Joined: Mar 2007
Posts: 499
Likes: 0
From: Erie Pennsylvania
is it carb or timing issues?
I have a 400 built up to a 408 with some high performance parts from tim meyer. it doesn't run correct however its not bad. it used to run a lot better when i just rebuilt the motor last summer. its seems to run hot once warmed up, however the temp has never gone over 200. once its warmed up, it will "pop" when taking off (manual trans), and hessitates when you step hard on the throttle. It also pops through the exhaust when you coast in gear. it doen't want to run as well when its warmed up. its not terrible, but it lacks power. the fuel milage also sucks lately. also, it "diesels" (turns over for a long time after its shut off) when you shut it off. do you think this is timing or carb issues? i have it set at top dead center. does it need to be retared or advanced in your opinion? I have a procomp (i know they're crap) ignition on it now, however the brand of ignition is not the problem i don't think. The carb is a 670 CFM Holley truck avenger and i did set the jets down a couple sizes. I need to get this truck running right, as it is my only vehicle right now, and it gets about 3 MPG (used to get 10-13) and doesn't run RIGHT.
Thanks,
TheBlueMule
Thanks,
TheBlueMule
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Have you done anything to it between the time it ran well and now? there could be many issues at play here, dieseling is most often the result of having your idle set too high.
As for the hesitation i'd check the accelerator pump and verify the vacuum advance is working properly.
You said you went down a few sizes on the jets, you may have leaned it out too much which would cause the "popping" thru your carb, the popping thru the exhaust sounds like an exhaust leak.
Where is your timing set at? all these symptoms leads me to believe it may be too far advanced.
As for the hesitation i'd check the accelerator pump and verify the vacuum advance is working properly.
You said you went down a few sizes on the jets, you may have leaned it out too much which would cause the "popping" thru your carb, the popping thru the exhaust sounds like an exhaust leak.
Where is your timing set at? all these symptoms leads me to believe it may be too far advanced.
Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 60
With the timing at 0 you now have the throttle blades too far open so the truck will idle, which is also the reason the truck is dieseling when whutting it off.
Advancing the timing will allow you to close up the blades a bit so it is more on the idle circuit.
This will also help with your mileage.
Josh
Laughing Gas
Joined: Jan 2007
Posts: 868
Likes: 2
timing should be ten minimum, possibly twelve if you put in a bigger cam. Running it at O degrees is WAY retarded. Hopefully you have not burned your exhaust valves out!
I would get timing light immediately and get that right. Then you can mess with your carb IF it needs anything.
I would get timing light immediately and get that right. Then you can mess with your carb IF it needs anything.
Junior User
Joined: May 2009
Posts: 87
Likes: 0
From: South Berwick, Maine
"it used to run a lot better when i just rebuilt the motor last summer".Sounds like retarded timing to me. when you rebuild it are you sure the timing gears are lined up? read your plugs, they will tell you a lot
Laughing Gas
Joined: Jan 2007
Posts: 868
Likes: 2
Trending Topics
Thread Starter
|
Senior User
Joined: Mar 2007
Posts: 499
Likes: 0
From: Erie Pennsylvania
i have the original jets and planned on putting them back in. thank you for helping me out. i'm not driving the truck right now, but i'm using my father's truck but in the next few days i will advance the timing and go from there.
Thanks,
TheBlueMule
Thanks,
TheBlueMule
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
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
Thread Starter
|
Senior User
Joined: Mar 2007
Posts: 499
Likes: 0
From: Erie Pennsylvania
well i got to work on the truck today. I crawled under and turned over the motor by hand. after sanding off the paint that covered the majority of the timing marks, i adjusted the timing to 12 degrees advanced, and set down the idle speed. The truck runs ALOT better, runs about 30 degrees cooler, and seems to take alot less effort to get moving. The truck still "pops" when coasting, but i'm going to change the jets back. Thanks guys.
thebluemule
thebluemule