Ford F-150 - 1997-2003 :: High Idle - Delay In Shift Intermittently?
Jun 14, 2014
So my F150 (with 4r70w) has a weird issue. If I jump on it (only briefly) and then drive normally it gets stuck in a high idle/late shift mode. Sometimes it won't even shift until 3500 - 4000 RPM. If I stop and restart it will usually go back to normal (depending on how warm the tranny is, the warmer it is, the less likely to fix on restart). Now I understand that if you give it a lot of gas it will shift later, but like I said, it get's stuck in this mode even if I have a light foot after. The really weird thing is that it does this after cruising on the highway for a while. Also, the OD light does not flash.
As I'm writing this, I just realized that a common thing is warm tranny fluid. I'm not sure if it's the tranny because the high idle and the fact that it will shift fine if babied. There are no codes.
Here's what I've done: Flushed tranny fluid and filter (full flush, not just the little bit with the filter change), replaced TPS, replaced PCV, replaced IAC valve, replaced a few vac lines, and cleaned entire throttle body (including EGR valve).
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2001-F150 5.4 Eng. bucking/stumble. I think my problem is slightly different than what I am reading about. Here is what I get (125k miles):
* Engine only bucks/stumbles intermittently and not at idle or at harder acceleration (this bucking is really harsh and makes the truck feel like a learner trying to drive a manual transmission and it is jumping down the street). The engine stumble is not a regular timing such as a cylinder going out and staying out for a period of time. It is quite a random pattern to the jumping
* Originally thought it was humidity related, but now I realize it happens in any climate
* No stumble in neutral at any rpm... only at a stop if I put it in a power brake load.
* When the stumble shows up, it seems like the throttle is around 10-25% (my best guess)
* Sometimes goes days without issue, but sometimes every ride and virtually every acceleration.
* Normally no stumbling at highway speeds, unless going up a hill.
* Every time it stumbles, it can be eliminated by either backing off on the accelerator some, or hitting the accelerator harder.
* No engine codes or CEL has ever come on
* Fuel mileage appears to be the same before and after the trouble started
Here is what I have done to try to correct it:
-> Fuel related (bad gas)... tried to run the tank as close to empty and fill it with fuel from different stations... when this didn't work, I have added HEET to it to dry up any water in tank.
-> Fuel delivery... replaced the fuel filter... seemed to work for one day, but then the gremlins came back.
-> Fuel delivery... ran multiple injector cleaners through tanks of gas.
-> Intake... replaced the filter.
-> Electrical... I don't believe this is related, but my battery died... parts store tested the system and stated the alternator was bad... replaced it, and took the old one to the parts store for bench testing and it was 100% OK... even thought the old showed OK, I left in the new one as a precaution. Only other item was a set of plug changes around 30k miles ago... I think I put in the super duper Bosch plugs with a lifetime warranty.
Current thinking and items I don't understand:
A) The bucking is so severe, it appears to be a random harsh loss of either fuel or ignition. A component that has failed electrically should give me a fault code with this level of severity. No trouble codes or indicators to electrically sense this disturbance...
B) For the fuel path, the most likely item is bad gas and I emptied my tank by running it as close to empty as possible and then used different gas and HEET to eliminate water. THIS MIGHT STILL BE THE CAUSE???
C) Another one for the fuel path is an intermittent fuel pump electrical connection or a weak pump from a pressure point. But if this is the cause, then why does it dissappear upon harder acceleration?
D) One last fuel thought is injectors... perhaps one or more have a range of delivery that they don't work properly... but this doesn't make much sense as at idle and harder accels are fine
E) From an ignition standpoint, perhaps I have failing COP's. I have not just gone out an replaced them due to my limited budget and the difficulty I read about changing them. Again, if one of these is failing in an either open or short condition, the computer should set a code for a misfire for the related cylinders. I get nothing. Hence my hesitation in making this change so far.
One thing i don't understand from the various posts is that the cops can fail under loading. what makes this happen as electrically, i don't think they can detect a load or not? it is hard for me to also understand why my truck would allow me to back off on the throttle or hit it harder and the issue disappears.
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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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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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I've got a 2003 ford f-150 with a 4.6l 150000 miles. when it is started the rpms are at 2000 for about a min. and a half then it drops to normal when its started cold. when started at operating temp. The rpms are at 2000 for about 30 to 45 sec then drop to normal. The iac, upper and lower intake gaskets, intake run controller valve, dfbe, low intake and shield, coolant temp. sensor, intake air temp. sensor, egr, egr regulator valve, maf, ecm have all been swapped out no vacuum leaks all line in good condition tps voltage reading of 0.84v...
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I will try to keep this short. Picked up a 2000 f-150 4.2 for my nephews first truck last night. Bought it blind against my better judgement, but the price was right. Got it home, odometer didn't work, fixed the solder joint and was happy it only had 132k on it. Heater core was plugged solid. Got it flushed and at least now its has luke warm heat until I have time for a full coolant flush and new core.
Next on my list is the high idle and engine lights. Its idles around 1300-1700, cold or hot sometimes it drops down. I only have a cheap scanner, but I have 2 codes. PO171 and PO174. Where should I start with diagnosing this? I would assume vacuum leak. Any common spots to check on these?
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corrected vaccum leak. Still high idle and obd2 code 1506???
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I have a '98 F150 4.2l with 230k miles on it. A couple of days ago when starting, I noticed that the engine kept racing instead of idling down like it normally does and the weather here in Arkansas has approached the 80 degree mark. The engine also doesn't idle down when shifting (I have a manual tranny). Where to start? I don't have any codes stored other than two for bank 1 and bank 2 running lean but they popped up many miles ago. I'm thinking either a vacuum leak or throttle control. I checked the operation of the cable and the throttle valve and they appear to be fine. Maybe the idle air control?
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High mileage 1999 4.6 4wd 5 spd: Needed to replace the rear ABS sensor and decided to clean the throttle body too while the battery was unplugged. Cleaned it around the butterfly and not much else. Truck idled at 750 BEFORE cleaning the TB. Now it fluctuates between 820 and 950 rpms. Also tends to stay at a higher rpm after pushing in the clutch and taking it out of gear.
Did a thorough check for vacuum leaks, nothing. After research, I cleaned the IAC and re installed (battery was disconnected then too). No improvement. Unplugged the IAC while running- ZERO change in idle. Installed new IAC, no change whatsoever. Unplugged NEW IAC, no change whatsoever. Is there an issue with the PCM needing time to fully re learn? Am I missing something.
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I had the transmission in a 2003 Honda V6 rebuilt in Nov. 2014. It is slow to change when starting off and slow to change into the next gear. Sounds like it is hung up for a while. Is this normal for a recently rebiult Transmission?
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My trucks symptoms include a illuminated service engine soon light, sometimes a high rpm idle, and sometimes a rough erratic idle. When a scan was done it indicated the oxygen sensor was defective. The issue is: which specific one (there are multiple oxygen sensors) or how could I check or determine the faulty one for sure. I am trying to economize and replace only the bad one myself if possible. I own a good multimeter, can it determine the bad one? 1999 F-150 4.2 Litre V6 oxygen sensor dillemna....
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My 2002 Ford F-150 4x4 4.6L 5speed strangely has a time delay in starting now. A delay in TIME and not the usually chucking along waiting to start. Or simply I turn the key and a second or two passes before anything starts to happen and it fires right up. Was wondering a few months ago, if my clutch sensor was going out but then it cleared up once I put a new battery in it although at the same time the weather warmed also. Bad connection somewhere, bad ignition switch, or bad clutch position sensor – I could go in each of these directions. Thought maybe the security in the key was doing it too but both keys have the same problem. No codes also.
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2000 f150 4x4 5.4auto tranny.
When I turn the key, sometimes i have a time delay before the starter kicks in. I replaced the relay on the firewall and no change. A couple of days ago I started the truck but the starter did not turn off when the key was released. I had to turn the key to off then back to run to get the starter to stop. Now today, I nearly got stranded by it. It took several attempts to get the starter to kick in.
To me this seems like a relay sticking. What should I try next?
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I have a 2000 X V10 and am having an intermittent high idle condition. I have searched the forums and found some useful info but nothing that addresses this issue. Here's what I've done. New IAC, found PCV valve hose leaking-replaced also new valve, found another vacuum leak-repaired, tested TPS and that was fine according to the specs I found. So here's my problem-upon starting engine occasionally "stumbles" then roars to life idles 8-1100rpm. Drives well till stopping at an intersection and idles 1100-1200 rpm.(lots of brake) Can pull into parking spot place in park and will idle up 1500-1800 rpm and then only drop to 1200 or so. I have checked everything I know. ALL these idle conditions are INTERMITTENT. (and yes I did check for codes "0" ) There is no loss of power.
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I have got the most aggravating electrical gremlin possible. For over a year now, the truck intermittently just dies. Mostly it happens about 2-3 mins after start (every couple weeks or so), then takes a couple of key offs, then back ons to restart. But it does restart and then runs fine for a time.... 2 weeks ago I was rollin' down the road and hit a pothole, and whammo, she died, and wouldn't restart. I thought, "great it was the intertia cut-off going bad." I had it towed to the shop where they did some diagnosis and told me it threw a PO231 code.
The tech then said he was doing the diagnostic manual directed test, and swapped out the fuel pump relay, and it started right up. New relay, out the door. A few days later on the way to work about 2 - 3 minutes after start, she dies again. I hang my head, say a curse word, and key it a couple times, and it starts back up and runs fine. Presently speaking she's back at the shop, but the owner, who's a straight up dude was loath to take her back, because it was running fine at the time.... I've got to figure this thing out before I drive it off a cliff.
Truck -- 2001 7700 XLT 5.4L 88K miles
Symptoms -- Random interval engine stops with short delay to restart, 1 hard bump engine stop with no restart. PO231 code (after the hard bump no restart). Didn't check it previously (wasn't aware there were "soft" codes).
Troubleshooting to date -- 1 new fuel pump, 1 new fuel pump relay.
Only things left are the inertia cut-off switch (which apparently don't go bad that often), and the wiring itself/connections to the different components....
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I completed the high idle mod on my '05 Excursion 6.0 a few months ago. The 12V source is the blue/white wire that up/right of the ODBII connector outlined in the high-idle mod how-to.
For some reason, every couple of weeks, the 10-amp mini fuse at #29 will blow. It will work well for several weeks - then randomly pop the fuse about once a month.
Not sure if maybe I should swap out the switch I'm using to toggle the high idle, or maybe if an increase in the fuse amperage is required...or something else?
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My Jeep does not always start. All the dash lights come on, but when I turn the key to start the engine, they all go off. The lights stay off, and the engine will not start. The ignition won't even click... it's similar to a dead battery. When I turn the key back to its original position (when first inserting), all the gauges spike and the needles jump really high for a split second. When the door is open the gauges keep jumping (spiking). After waiting for 30 minutes, the engine will start fine like nothing was wrong (except the fluctuation in idle). It would rev high at idle sometimes, and sometimes it would idle low... so low in fact the jeep stalls. I have read about the symptoms of crank/camshaft sensors and relay, but I wanted to make sure from people that know more than I or have faced this particular problem.
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My '01 recently seized up and a buddy determined it was the AC pump. Replaced the belt with the bypass version. A month later, I moved across the state to Iowa. A couple weeks into living here I turned the truck on and it was idling really high (about 2500-3000) but would settle down to around 1100 when put in gear. However, shifting into gear is causing a progressively worse "jump" into gear. Hadn't really had the money or the time to take it in so I let it mostly sit unless I absolutely needed the truck.
Today, the idle is still high and does seem to cycle a bit in that it will rev up close to 3000 then settle back down around 2200 or so and then rev back up again and so on. I backed it down the drive into the sun for a little warmth and it darn near jumped a foot when I shifted. I turned the heater on defrost so I could clear the windshield and absolutely nothing came out.
I can't get into a garage for a few days to get it hooked up for diagnostics. So I thought I'd try here. My research leads me to think part of my problem may be a vacuum leak and/or maybe a sensor somewhere.
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2004 Grand Cherokee. I was pulling a heavy trailer 1000 miles, and while coming down a mountain pass 50 miles from the end of the trip the check engine light came on. All other gauges (oil pressure, temperature, etc.) had not changed while climbing or descending and I was in low gear while descending to save the brakes. I drove the rest of the way to the destination without incident. I tried turning the Jeep off and restarting it several times to see if the check engine light would turn off and it stayed on. The next morning the light was off when I restarted it and has not come on again since. I hooked it up to a scan tool and received 2 codes: P0152 and P0132. 2 days later I noticed that it was revving high while idling and in Park. It would rev between 1500 and 2200 RPM while in Park, and at 900 RPM while in Drive. Also, while travelling at freeway speeds it seems like it's trying to downshift for no apparent reason. I hold the throttle still and have even tried cruise control and it intermittently increases engine speed, without changing ground speed. I assumed that I got the transmission too hot while climbing/descending and that the error codes listed above (related to O2 sensors) were associated with that, but now I'm wondering if something more has happened.
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I have a 08 6.4l F250SD. At 127k miles, it has been a great truck. All service has been performed by dealer. When I shift from Park into drive there is a 3-5 second delay, and when it drops into drive the truck rocks. Once driving there are no shift issues. Into reverse there are no issues.
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1998 F150 XLT 4x4 4.6L Auto.
Bought this truck two months ago, the lot had the engine rebuilt due to bad bearings, so fresh motor. They forgot to recharge the AC, so I had them charge it when I purchased it. It blew icy cold every things until a few weeks ago. It wouldn't work, then randomly it would, then it would quit, etc. Today it's 97 and I had it on with my kids in the truck, hot air.
I tried turning it off and on, still hot.
I tried seeing if the temperature was stuck and moved it to hot, it got sweltering hot, back to cold, just warm air. There is no difference between vent and max AC.
I went to the store, picked up a refrigerant filler with gauge and a can of R-134. I hooked it to the low end of the system and was surprised that my pressure was about 60PSI. Great, they over filled it at the dealership. I released the pressure down to 40psi and checked, sill hot. I figured maybe something was weird and they might have mixed good refrigerant with bad and that's why it was intermittent.
I released all the pressure down to 0 PSI. I then put on the can of R-134 and filled it to spec. Sill hot air. I removed the harness from the pressure switch and jumped it, getting sparks when I connect the wire, so it's connecting, but still hot air, probably not the switch.
What's going on here? Could they have over filled it and killed the system or something? What is likely broken here? My heater works like a champ, my AC just blows environment temperature air.
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