engine performance problems
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 214
Likes: 0
From: Hephzibah Georgia
engine performance problems
recently i've had problems with my truck not performing well. the problems have gotten worse. i though it could be a lack of engine vacuum. i tried to seal up the vacuum tree at the rear of the intake and i believe i have it fixed. But now i still think there could be a vacuum leak. how many places can i check out for possible loss of vacuum.
Heres what its doing. If i am at a stop. Engine hot or cold. As I start to accelerate it seems sluggish, then picks up, shifts, RPM's drop lower than it normally does, then slowly starts to pick up speed. Its shifts again and RPM's again drop lower than normal. Its not very smooth now either. Instead of the engine steadily in creasing Rpm's and speed it loses power and jerks more rather than gently increasing in RPM's, shifting, increasing rpm's and leveling out.
specs on truck in signature
Heres what its doing. If i am at a stop. Engine hot or cold. As I start to accelerate it seems sluggish, then picks up, shifts, RPM's drop lower than it normally does, then slowly starts to pick up speed. Its shifts again and RPM's again drop lower than normal. Its not very smooth now either. Instead of the engine steadily in creasing Rpm's and speed it loses power and jerks more rather than gently increasing in RPM's, shifting, increasing rpm's and leveling out.
specs on truck in signature
Elder User
Joined: Jun 2003
Posts: 886
Likes: 1
From: Houston/Hope BC
I guess you know about spraying carb cleaner around the base of the carb and intake manifold to check for leaks.... A couple of places that may also be affecting you are: vacuum advance diaphram, modulator, PB booster. Hook up a vacuum guage or RPM guage and note any changes as you disconnect and plug these hoses. I am guessing this might also be an ignition issue. A friend at a shop with a scope might be 5 minutes well spent. Good Luck.
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 214
Likes: 0
From: Hephzibah Georgia
i believe the vacuum leak is coming from somewhere behing the carb. i can hear it fairly close to the fire wall while driving. i may have a fouled out plug as well but i haven't got anything definite yet. i know this is a heavy truck but it isn't always this hard to get down the road.
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 214
Likes: 0
From: Hephzibah Georgia
i believe i got it today. the number 5 spark plug was fouled by carbon. i checked the vacuum today with a gage and it read around 24 pounds, steady. so i think i got it. yet i still need to figure out the power steering leak. does anybody know of the UV radiant dyes that you can add to like your oil and see where it's leaking from. i wonder if auto zone would carry that?
Thread
Thread Starter
Forum
Replies
Last Post
xjcamaro89
2004 - 2008 F150
463
Feb 13, 2026 05:07 AM
HEpTJJ
1987 - 1996 F150 & Larger F-Series Trucks
8
Sep 11, 2013 10:58 PM
