rough idle
Thread Starter
|
Senior User
Joined: Jul 2009
Posts: 177
Likes: 0
rough idle
I just recenly put the holley 390, clifford, hooker headers, dSII setup on my truck and it runs ok. idles rough. its pulling a steady 17hg on the vac gauge and im still fine tuning the carb but man it runs a little "rougher" at idle than i think it should. Also another big thing is when i turn the wheel when the vehicle is not moving, the engine nearly dies out. i have to rev it up a little to turn the wheels when the truck is not moving. Ex is pulling into or outta a parking spot at slow speeds.
plugs and wires are all new. what are some things i could try to help fix the rough idle and turning issue i got.
Maybe its normal i dont know, how does yours guys trucks run who have done the clifford/ offy swap??
plugs and wires are all new. what are some things i could try to help fix the rough idle and turning issue i got.
Maybe its normal i dont know, how does yours guys trucks run who have done the clifford/ offy swap??
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
sounds like you have a vaccume leak. spray brake cleaner around the carb, and intake to head. listen for the idle to rise, and you have found your leak. I had to use copper seal on my carb gaskets to spacer,and to intake, it stoped leaking then, and ran great
Thread Starter
|
Senior User
Joined: Jul 2009
Posts: 177
Likes: 0
well tonight i was searchin for vac leaks and found my clifford manifold i bought off some guy on ebay had a small crack in it causing the leak. put some good ol JB weld on it and the truck seems to run better. pulling alot better vac now. around 18 19hg steady, but still runs rough. I have the timing advance a little over 10 degrees to smoothin it out.
also i dont know if anyone else who did this swap has the problem i have of the accesories really putting a load on the engine. if i have the heat goin, lights on and turnin the wheel at a slow speed, the dam thing dies out on me. its a little better now ever since finding the vac leak.
And to anyone who is thinking of doing this swap. DO NOT i repeat DO NOT GET HOOKER HEADERS. they are JUNK JUNK JUNK. surrounds the starter and the pipes come down and meet the trans crossmember so there is no easy way to hook up the rest of the exhaust. **** pore design and for 400 bucks. i made the mistake please dont anyone else.
also i dont know if anyone else who did this swap has the problem i have of the accesories really putting a load on the engine. if i have the heat goin, lights on and turnin the wheel at a slow speed, the dam thing dies out on me. its a little better now ever since finding the vac leak.
And to anyone who is thinking of doing this swap. DO NOT i repeat DO NOT GET HOOKER HEADERS. they are JUNK JUNK JUNK. surrounds the starter and the pipes come down and meet the trans crossmember so there is no easy way to hook up the rest of the exhaust. **** pore design and for 400 bucks. i made the mistake please dont anyone else.
Posting Guru
Joined: Jun 2009
Posts: 1,174
Likes: 0
Sorry to hear about those hooker headers. Didn't know hooker made 300 headers. Thanks for letting the rest of us know. Oh and this same thing happened to me when I took my stock manifold off and put it back on again. Turns out I pinched and folded my intake manifold gasket over so there was a big leak between the head and the manifold. Had to redo the gasket. A good way to tell if you have an air leak is to put your hand over the top of the carb, covering and restricting air intake. If it helps the problem at all, you are running too lean for some reason.
Trending Topics
Postmaster
Joined: Dec 2006
Posts: 3,603
Likes: 10
From: Spokane, WA
Try changing the vac source for the dizzy between the timed port on the carb and a full manifold vac source then readjust the carb and try. Mine will run on either source BUT the throttle plates have to be opened further via the idle speed screw to get a decent idle on the timed port so I opt to run off a full vac source.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Thread Starter
|
Senior User
Joined: Jul 2009
Posts: 177
Likes: 0
i put a shop rag over the top of the carb like you said. What is it supposed to do when i do this. What my truck does is you cover up the carb and very slowly (it takes about 30 secs to start doing it) it will die out. and then i let air back in and comes back to life. What does this test prove??
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
when you cover the carb, it should stall out. if it don't stall out, you still have a vaccume leak. in your case, not a big one, but you still have one. they're a real pia to find, but when you do, you will notice a big difference in how the truck runs
Thread Starter
|
Senior User
Joined: Jul 2009
Posts: 177
Likes: 0
i covered up the timed spark port on my holley and hooked up the vac advance to a full vac port, and it made a huge difference. Also for you guys with a off idle hesistation problem, heres what i did and it fixed it. First obviously check the timing. next put the vac advance to full vac port. next i got a bigger shooter for the carb .037, and a secondary spring kit. Installed the black spring which has them open at about 2200 rpm and the truck has no more bog at all. but i still have a rough idle can hear it skip a beat by listening to the exhaust.
Is it possible to get a MSD kit to help out with spark for our trucks. I like to make sure im burning all that fuel and air mix going into the engine.
Is it possible to get a MSD kit to help out with spark for our trucks. I like to make sure im burning all that fuel and air mix going into the engine.
Thread Starter
|
Senior User
Joined: Jul 2009
Posts: 177
Likes: 0
truck still misfires. it may be comming from the intake gaskets leaking i dont know. probably will just change them again. Also one more question is when i rev the engine i get smoke coming out of the breather, or dipstick hole if i have it opened up a little. Not alot but its more than its supposed to be. I have an aftermarker breather in the valve cover. it has a New pcv. Any suggestions on what it could be
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
hook your pvc hose straight to the intake instead of the bottom of the carb. check your plugs to see if 1 is fouled, the smoke is blow by. take a compression test while the plugs are out to see what's goin on. usually blow by indecates worn rings