Ford F-150 - 1997-2003 :: 2001 - Intermittent Drop In The Idle From 700 To About 500 RPM
Sep 6, 2004
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?
View 8 Replies
Advertisement
So my truck started to intermittently misfire about a month ago . I changed the spark plugs wires at first and it seemed to get better but it still had a misfire . I replaced the spark plugs and ignition coils and the misfire is still there . Up until the other day it was a noticeable issue but still drivable with . On my way home from work it got alot worse and started to misfire any time I tried to accelerate and now is noticeable at idle now as well.
I checked the fuel injectors resistance and they are about 14.8 ohms . I am not getting any codes for a misfire . I tried to pull the fuel injector connectors to try to find the source of the misfire but could noticeable change in engine rpm. Where to go from here and what I should check first? Would a clogged fuel filter cause something like this ?
View 9 Replies
01 supercrew 4.6. Have had intermittent no start. The first few times it did start with a jump. Cranks fine but I thought the battery was weak. Replaced battery, same issue. 40 psi gas pressure at the fuel rail with analog gage. Theft light blinks with battery inserted. Theft light not illuminated while cranking. Battery light flashes while cranking. Battery is brand-new and charged. Opened and closed inertia switch several times to check.
View 12 Replies
I found no heat last week in my 01 F150. The AC was cold but no blower. The heat was there but no blower. I replaced the blower motor resistor. Result: i believe a FEW of the speeds worked when turning the fan speed switch...but was intermittent. It would blow L, M, H, then nothing. I jiggled the know on the dash mounted switch and heard it on/off, on/off the motor as I jiggled. I DID notice that when I disco'd the connector off the resistor the HIGH speed worked. Is the switch on the dash perhaps crusty ? Or should I be looknig at the motor itself.
View 4 Replies
I just purchased a 2001 F150 XLT with a 5.4 engine. If I start the truck and let it idle, it will hold steady around 900rpm's. If I give it a little gas and then let of (all while in park). The rpm's never come back down to 900. It hangs at approximately 2000rpm's. If I turn off the truck, wait a few minutes, start it back up, the engine idles fine again at 900rpm's. If I give it some throttle again, the same scenario takes place.
View 8 Replies
1997 Olds. Bravada. 4.3L original engine. 217000 miles, maintained well (routine oil changes, fluid checks, etc)
Intermittent stalls. When stalling, voltage found to drop to 0 even though radio, headlights, and dash lights remain functional. Engine will sometimes "automatically" return to running (it doesn't turn over, just runs) and the air bag light flashes, other times it needs to be restarted. No problem restarting, but may or may not stall a few seconds later. No specific action triggers the events. On a potential side note, the rear wiper motor will spontaneously start running occasionally (once per week frequency typical).
Attempted fix: cleaned both battery contacts, removed and cleaned frame ground, removed and cleaned body ground, all done with either sand paper and/or a wire brush
View 1 Replies
Twice now this has happened to me and I'm concerned it will become worse if I don't fix it. Driving down the road my engine has disengaged. By this I mean the vehicle both times has been at 55 MPH, my foot on the throttle rpms riding around 1300 revolutions, and the engine disengages rpms drop below idle and my "wait to start" light comes on. This both times lasts approximately 2 seconds and throttle reengages while still traveling 55 MPH, "wait to start" light goes off and its like it never happened. What's going on with my truck? Ford diesel 97 250 7.3 ...
View 2 Replies
1997 escort lx wagon, manual, 173,000 miles... When I stop at a red light or stop sign, it takes 10-15 seconds for the idle to drop down to where it should be, and when I push clutch in to shift gears it doesn't drop down, it stays where it is. No codes are coming up. I'm thinking IAC....
View 9 Replies
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!
View 5 Replies
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.
View 8 Replies
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.
View 4 Replies
My 1997 f150 5.4 has started an idle issue. The truck when started will idle around1200 rpm and not settle down After driving a bit it will drop down around 800 and idle rough and sounds like it has a plug fouled. As soon as you give it gas it clears up and sounds fine, then drops down an idles rough.
Checked for vacuum leaks but don't see any. pulled the MAP sensor and cleaned it, but did not change.
View 7 Replies
Two weeks ago Sun, truck ran fine, however Mon morning all hell broke loose. Truck was running very sluggish and stalling while coming to a stop. My first thought was tune up. I replaced the plugs and wires. During this I found that i could not get a socket around the ever loved driver side rear plug so i was only able to replace 7 plugs however in that process i managed to break the metal coolant tube that runs to the heater core.
Aday later replaced the entire intake manifold,egr valve, egr tube, IAC valve, both coil packs, fuel filter, tranny fluid and filter. During the removal of the intake i looked at the rear spark plug and found that a screw had been wedged into the hole breaking the plug and got it changed now it is all back together and the truck runs amazing however did not solve the low rpms during stopping. ive replace the above and checked fuel pressure which is good.
I have a TPS sensor just haven't installed it yet not sure if it is related to the issue. Tranny guy says it may be a bad solenoid or TC however last night I reset the PCM and drove it it ran flawless. this morning the problem returned which leads me to believe its not the tranny. ok one last kicker that 6 experts have failed to answer when i manually put the truck into 2nd gear the engine dies! no studder no fighting just quits.
Truck is a 98 F150 4.6 V8 186,000 miles i have yet to
1) change TPS.
2) clean throttle body.
3) clean MAF sensor. n
Not sure if any of this has an effect on the issue. There is only a EGR insufficient Air flow code..
View 14 Replies
I have a 1997 F-150, 2 wheel drive, 4.6L truck. Recently the transmission got to where it didn't shift properly. Then it got to where, after driving it about 10 to 15 miles the transmission would drop out of gear with the transmission selector in drive.
I have replaced the transmission sensor, the rear end sensor and it still does the same thing. Drive about 10 to 15 miles and, with the transmission selector in drive the truck will not pull. The motor can be rev'ed but the truck won't move just like it was in neutral.
What is wrong. The transmission shifts fine, the truck runs fine, but after 10 to 15 miles the transmission quits working.
View 1 Replies
It just doesn't end lately. I've noticed over the last several months, when it rains and I start the engine I would hear an underhood squealing noise. Like a belt or pulley. After the engine warmed up a bit, and the engine bay dried out, the squeal would go away. After a rain about a month back, I opened the hood to listen but wasn't able to locate the exact source of the squeal. Never gave it any more thought.....until this evening. I was driving in our New England Nor'easter in 4 whl drive mode with the wipers on HI, the defroster and blower on HI, and the headlamps and dash lights illuminated, when suddenly the dash lights dimmed about 40%, the blower slowed down about the same, and the wiper speed dropped as well from HI to about low speed. This was shortly followed by an underhood squeal which sounded a lot like the one I've experienced recently. After about 20 secs, the squeal would disappear and the power would quickly return to all accessories! This happened about 4 or 5 times and I returned home and parked it as I did not want to be stranded during the blizzard with a dead truck. The battery voltage gauge needle on the dash never seemed to move so I'm a bit stumped.
View 14 Replies
So I know there has been lots of posts on surging issues and how to troubleshoot. My truck is a 97 f150 4x4 xlt 4.6l v8. I have noticing surging and dropping in my RPMs lately. No CEL. I have kept a journal when I notice when it happens. I only have issues when I am driving around 40-50 mph and if I go over bumps/pot holes/rough spots in roads or when I'm braking over bumps/pot holes/rough spots, my truck surges/RPMs drop CEL flashes on and off only during these instances. Makes me think something could be loose or something causing this. It has stalled at times when having to brake fast (yellow light, etc.). Where to look first? 1997 F150 4x4 4.6 V8...
View 1 Replies
I have a 1997 forkd F150 with a 4.6L Romeo engine. I have recently rebuilt the engine and now since it is put back together I am having a issues that i cannot pin point. When the truck is running and in gear my RPM drop to around 500 or below and my oil pressure drops and comes back up when the rpm's come back up this an intermittent problem and I have replaced the IAC valve and every once in a while i get a P0401 code for the exhaust recirculation. I think I am loosing some kind of vacuum. It was not doing this when I tore into the truck. It seems to be running okay not hesitation.
View 2 Replies
4R70W. This one is in my 99 F-150 with the 4.6. From what the previous owner told me this trans only has 13k miles on the rebuild and I believe him because the converter is bright blue and when it does shift right, the shifts are solid and fluid is very clean. Truck only has 98k miles on the body as well, so it's possible the truck did sit a while because my tires have a ton of tread on them, but they are dry rotted a bit (dated 2006 IIRC).
Issue: When the trans is cold (sat overnight) it will shift to neutral between the 2-3 shift for 1-3 seconds depending on outside temperature and then drop into gear. But it only does this for the first 30 seconds or so of driving, after that it shifts normal (although it does seem to hold gears a little longer than I would think it should on occasion and not upshift). I have only gotten it to do it once per cold start so it seems like once the trans gets any heat it's fine.
I was also thinking I was getting drain back and maybe it wasn't heat related so I dropped the pan, replaced the filter, fluid and pan seal (it had a small leak) and torqued the valve body. Two of the bolts were a little loose, but the rest were fine. Tightened them to spec and put it back together with no dice. Truck also gets pretty bad fuel mileage so I'm starting to think maybe there is some temp sensor screwing everything up?
View 12 Replies
My '03 7.3 is "surging" on idle. When warmed up, and idling, the RPMs will drop by 300 or 400 for a few seconds and then will correct and shoot back up. It cycles like this (every 5 seconds-ish) continually . I just put in a new IDM and checked the UVCH - is there a separate idle control mechanism that I need to have a look at? (2003, 7.3, 214K, stock).
View 14 Replies
I have a 1997 Audi A4 that has been acting a little bit strange lately. When it is started up and left to idle all of a sudden the RPMs drop from around 600-800 to 100-200 sometimes rebounding back up and sometimes the car just dies. This also is happening while I am driving and stopped at a stop light for a short time. It will idle fine then suddenly drop RPMs and if I don't give it any gas then the car usually dies. I have just had some work done on it to try and fix this problem thinking it was the air flow sensor (or something like that) but apparently that is not the case.
View 2 Replies
Recently I have noticed that when on a tune other than stock I am getting a surge at idle - my RPMs drop to around 621-630 then shoot back up to 660-675. On my stock tune my RPMs stay around 640-667 and don't cause the surge (felt as a shimmy so to speak). Is there anything else that causes a similar symptom? I attribute it to tuning due to it only happening when running anything but stock but could be wrong.
View 2 Replies
