Idle jumps
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Idle jumps
Hey, guys. Im new to the site, but long time Ford truck owner. So the other day i was at a light stopped and in drive sitting there and the idle jumped down about 100 rpm or so, seemed to stumble down for a few seconds, then went back to normal. Now it hasnt done that for a few days. Until today at a light, the same thing happened. I have a duel tank and i know the first time it did this i was on tank 1, and today on tank 2 for fuel. Anyone have a situation like this, or any advice on what to look at first? Any advice is greatly app. Thanks in advance
Postmaster
Joined: Mar 2011
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From: Taxachusetts
Check the green(?) wire on the TACH TEST terminal of yer coil....as well as the other connections. The tach runs off the (-) terminal on the coil....if you still have an unbutcherd DSII ignition system
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I checked all my connections that are ignition related. Plug wires, cap, coil, etc... when the idle does drop down, you can actually feel the engine drop, not just the tach droppong a couple hundred rpms. Truck actually stumbles. Thanks for your reply
Postmaster
Joined: Mar 2011
Posts: 2,698
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From: Taxachusetts
Ok...if yer wiring/connections/plug wires/rotor/cap, etc are all squared away then the next troubleshooting tip would be the fuel delivery system.
How old is the gas?
Rubber fuel lines in good shape?
Fuel filters clean/unobstructed?
Carb(?) adjustments good? Carb's innards clean?
Other carb accoutrements (choke, anti dieseling solenoid, etc) in good working order?
No vacuum leaks....(kinda obvious but I had to ask)
How old is the gas?
Rubber fuel lines in good shape?
Fuel filters clean/unobstructed?
Carb(?) adjustments good? Carb's innards clean?
Other carb accoutrements (choke, anti dieseling solenoid, etc) in good working order?
No vacuum leaks....(kinda obvious but I had to ask)
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Ya, went there next. Gas is new, its fuel injected. So all lines look good. No obvious vaccum leaks. Went to do the fuel filter, but could only get one side off, and other seems like its going to need some more muscle. I ran out if time and had to put back together. So will try again this weekend.
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Ya, not sure whats going on. Now it hasnt done it since saturday. And its only done it 4 times in the last couple months, so its hard to put fingure on it... the idle has always seemed to be alittle low to me. When in park it idles at about 850 which seems fine, but when in drive its goes to 690 to 700. I know it will always be lower rpms when in drive due to load, but just seems low to me. Is that a normal range?
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Postmaster
Joined: Mar 2011
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From: Taxachusetts
In gear, an automatic at idle - you'll like to see around 650 RPMs. Your current idle condition seems a bit high, but fine....not a problem.
With computerized(?) fuel infection it's difficult to set the idle, if at all. A different chip might solve the problem but if she's runnin' fine, why mess with it?
Try to note what you were doing with your rig the next time it happens....as in slowing down for a stop from...say 40 MPH? And it only happens settin' at a light/stop sign.......a poser, indeed.
With computerized(?) fuel infection it's difficult to set the idle, if at all. A different chip might solve the problem but if she's runnin' fine, why mess with it?
Try to note what you were doing with your rig the next time it happens....as in slowing down for a stop from...say 40 MPH? And it only happens settin' at a light/stop sign.......a poser, indeed.
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