Ford F-150 - 1997-2003 :: 2001 - Intermittent Drop In The Idle From 700 To About 500 RPM

I have a 2001 F150 with the 4.6 engine. I get an intermittent drop in the idle from 700 RPM to about 500 RPM. The computer catches it quickly and brings the idle back up. It might drop several times and clear up or it might not happen at all. Seems only to happen on a hot engine, never when cold and in gear, if in park or neutral seems to idle ok. Changed the idle air control valve but no different. Runs fine except for the idle dropping when stopped.

Never get a check engine light, and no codes from the computer when I had it checked. Could this be the vapor management valve turning on?

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Ford F-150 - 1997-2003 :: 2001 - Rough Idle In Cold Weather

Have a 2001 F150 FX4x4 and since the weather changed and started having days below 40 the truck has started running rough for about the first 15-20 miles. When you first start it starts like normal for first 3-5 min and then it starts loping real bad like it has a cam in it!

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Ford F-150 - 1997-2003 :: 2001 - Got P0357 - Replaced Coil - Rough Idle?

Sunday my truck began to sputter at idol while at a light and continued when parked. My first assumption was another coil pack has gone out. Went to autoparts store to get a new one and run the codes to tell me which cylinder it was. Code P0357 came up referring to cylinder G which seemed odd to me as it usually gives me a number rather than a letter. Bought the coil pack and went home to swap it out. Replaced the coil and with no change in the idol I googled the code. I have now replaced the coil, inspected the plug and wires around the plug and now I am at a loss of what to do next.

There is only a rough idol, no hesitation when driving or accelerating. Along with that, I've notice that if I'm going between 30-50 and take my foot off the gas it doesn't slow down, it's as though the cruise control is on... After a few miles on the highway and come to a stop, the RPMs are around 1k for about 30 seconds then drops to almost stall before catching itself and begins to sputter.

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Ford F-150 - 1997-2003 :: 2001 - Fog Horn Sound Coming Form Left Side At Idle After 4.6L Warmed Up?

My '01 F-150 2WD, XLT has a foghorn sound coming from the left front side at idle after the 4.6L is warmed up. It goes away with an increase in engine RPM and is unnoticeable at hwy speeds. I have no codes (I have checked w/ my code reader). The service desk guy at the stealer said it is my abs pump going bad (I figured it was a pump of some sort, my 55 packard PS makes the same noise when almost empty-the system leaks). It also appears this is a stealer only part, and going to cost 6 or 7 benjamins to buy and probably another 5 benjamins too fix.

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Ford F-150 - 1997-2003 :: Missing When At Idle

it's missing at an idle and it acts like it dont wanna take gas but once you get it going on the road it does good. the motor is a remanufacture motor it's only got 6,000 miles, new coils, plugs and wires, cam sensor, crank sensor, idle air control, mass air flow,and temp switch.

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Ford F-150 - 1997-2003 :: V8 Cranks But Will Not Idle

My f150 cranks but will not idle unless you hold the throttle at 2 rpm. It has not ran hot. There is no oil leaks.

I've changed the following parts:

Cam sensor
Crank sensor
Fuel pump
Fuel filter
Coils
Spark plugs
Iac
Tbp
Maf
Fuel pressure
Pcv

I've have tried everything i can think of so i took it to a shop they said just get a new motor I don't think so.

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Ford F-150 - 1997-2003 :: Starts But Not Idle?

So, I don't use my F150 too much and an animal made a nest int the intake tract and the nest material (chewed up air filter) got sucked in the throttle body all the way to IAC valve. So I thought I cleaned everything out, even got a new IAC. It starts now but just dies. I didn't remove the throttle body, should I? Where else do you think I could I find this stuff?

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Ford F-150 - 1997-2003 :: Rough Idle At Start Up

I just acquired a 2003 with 5.4 L. Did all new plugs and coils, cleaned MAF sensor, changed air filter, oil, transfluid and filter (obviously not related).

Upon start up and idle the truck has is rough, enough that it will vibrate the whole truck SLIGHTLY. Once in gear and warm, it smooths out and is fine. Unit the next stop and start.

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Ford F-150 - 1997-2003 :: High Idle Now No Electric

So, yesterday I noticed the idle was higher than normal. In drive I'm at 950 to 1000 rpm and in park it's about 1150 to 1200. It's kind of like a cold start but never backs off and does this when things are warmed up also.

I replaced the IAC Valve about a month ago cause I got tired or cleaning it. The condition was a low idle and fluctuation when I came to a stop.

To test for the new conditions I have been reading that if I pull the plug on the IAC that the idle should drop if it's working?

If there is no drop in RPM then it could be the TPS? 1999 5.4....

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Ford F-150 - 1997-2003 :: 4.6 Lumpy Idle When In Gear

Recently I just purchased a 1998 F-250 (light duty) with 11X,XXX miles on it. Up until today, it was running perfectly. However, today it started idling rough whenever I was at a light. This was only when I was stopped, in gear, with my foot on the brake. In neutral or park it didn't do it, and it stopped as soon as I gave it a little gas. No CEL either. I've looked around, and saw that it might just be "feature" of the 4.6. I also have seen to clean the MAF, but wouldn't that also give a rough idle when in park/neutral? Same with replacing the coil pack.

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Ford F-150 - 1997-2003 :: Idle Very Rough Like A Misfire

I got a 97 f150 4.2l from my neighbor. he takes good care of his vehicles. he sold it to me cuz it started to idle very rough like a misfire. it is hard to start when cold spits sputters and pops. once started idles like it wants to stall, then will idle normally then back to rough. back and forth like that. runs like a champ when going down the road . check engine light was on took it to auto store they checked codes . said bad o2 sensors so i changed them. still same issue. neighbor changed coil packs checked spark plugs and wire. every thing fires good. i changed iac. still didn't fix problem. could this be a bad egr valve or sensor? if so how can i diagnose this? he also thought was a clogged cat and bored it out. tight budget can't afford to take it to a mechanic. Was told spray carb cleaner spray around engine to check for leaks that did nothing at all...

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Ford F-150 - 1997-2003 :: High Idle After Warm Up

1999 F-150 5.4L. I just removed the clutch fan and installed two electric fans about two weeks ago. The same evening, I took a short drive and noticed the idle was way higher than it normally is. Its idling about 800 to 900 RPM. Now, the weird part.....Startup is normal, as in the idle jumps up for the warmup, then drops to the normal 600 to 700 range. after a short drive, the idle is high and noticeable at a stop.

Sometimes, if I let the truck idle, after about 10 mins or so the idle will slowly start creeping up a little at a time till it hits about 900 or so and will level off. I have tried the IAC, I have tried disconnecting the battery and letting the PCM reboot, I have checked ALL my vacuum lines, I have checked my TPS sensor and voltages, checked my MAF sensor and voltages, fuel pressures, everything I could think of...

I hooked up my scanner (Auto X-Ray 6000) and checked all my running data, nothing really sticks out to me as outta whack. No codes set..

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Ford F-150 - 1997-2003 :: Idle Roughly - Shakes?

Truck seems to have a rough idle not bad I had kid in back seat and ran into store came out and he asked why my truck was shaking. Plugs been changed dunno anything else I could do.

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Ford F-150 - 1997-2003 :: Rough Idle When In Drive

I bought this truck used and when it's in drive the engine idles rough and seems about to stall when the ac is on at a stop sign or red light.. I've tried it w/o the ac on and it seems a little better but not as smooth. Idle in park is fine.

When I should start looking? Spark-plugs? spark plugs wires, disturber cap, fuel filter etc...

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Ford F-150 - 1997-2003 :: 1999 - Low Idle With No Codes?

I have a 1977 f250 460 with c6. As far as I now everything is stock on the motor. The carb is a motorcraft but I cant see what model it is, there is a ID tag that I need to get the numbers off of so I can see what I have.

I don't know much about carbs so I'm trying to learn as I go, but what has me wondering about the secondaries is going up inclines. We have a canyon that is a decent grade and long, I was towing a empty flatbed trailer and with my foot all the way down could never get it above 40 mph it just felt like that was it. I have been out playing with no trailer and it feels like I can get them to open up when it down shifts, but cruising along at 55 and stomp it nothing.

I am worried about pulling our camp trailer with it and that is the main reason I got the truck with a 460. What to check?

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Ford F-150 - 1997-2003 :: Stalls At Idle - No Codes

My buds 2003 4.6 liter stalls every time he takes his foot off the pedal. Runs fine otherwise, no roughness or anything, you just have to keep your foot on the thing to keep it from dying out.

We checked for codes and found none. I checked vacuum connections and they looked OK.

Is there an easy way to test the IAC or should we just throw a new one in and cross our fingers? If we do change it out, does the truck need to be driven around a bit for the computer to re-learn anything?

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Ford F-150 - 1997-2003 :: 1999 5.4L - Low Idle With No Codes

The truck ran fine this morning and this afternoon I had trouble with the truck running at idle.

The idle is at about 450RPM in park. Runs smooth with no miss but if you bring the idle up and then let off quickly it stalls. Can stall while trying to idle at warm up also. Sometimes it will stall at a light but I think it is related to taking my foot off the pedal quickly.

There is no check engine light on and there are no codes. I have 138K on the engine now. Both air & fuel filter were replaced about a month ago as well as the PCV valve.

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Ford F-150 - 1997-2003 :: 2002 4.2L - Surging Bad At Idle

I am having great difficulty trying to figure out why my truck is surging so bad in park or in gear at idle. I have to mat the brake while in drive to prevent me from ramming the car in front of me. It all started when I replaced the air filter. Everything I've read leads me to the EGR valve, but that has been bypassed.

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Ford F-150 - 1997-2003 :: 2002 - Vibration At Idle?

I have 2002 5.4L f150 120k miles. Bought it almost 2 years ago and did not notice this vibration at the time but it could have been there and I didn't realize it. The trans was replaced by ford with a reman at 90k. I'd assume they inspected the trans mounts but who knows.

At idle only, there is a vibration. Enough that I can see water in a bottle moving and a plastic bag shake., felt through the seat, hand on engine can feel it, can feel it through the door..etc. Very annoying. At 700-750 rpm it goes away. Happens in all gears. I don't want to shotgun approach this. What I've done: Replaced plugs and coils since it needed them anyway. They looked good! No difference. I've sprayed the maf down and cleaned the throttle plate (I know your not supposed to but some 16 year old will try to tell me it cured his idle and he gained 10 mpg, so I figured I would mention it). I've removed the IAC and cleaned it, plunger moves freely. My idle does not fluctuate. I have watched mode $6, it's not a misfire. I have removed the pcv hose and checked for cracks - it's in good shape. Replaced the pcv since it's cheap. Ran Chevron tehcron through it. Checked codes - nothing. I have an edge and it happens on all tunes as well as stock.

I have ability to read live data but do not know enough to interpret it, so that is about useless unless you can provide me acceptible ranges.

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