Ford F-150 - 1997-2003 :: Motor Will Turn Over Fine But But Immediately Stumbles While Trying To Start
Jan 24, 2015
This 97 F150 4.2 is new to me, originally a very base 2wd white fleet vehicle, with 189,000 miles, runs smoothly and quietly, idles well, transmission shifts smoothly. Gets reasonable gas mileage.
Problem statement: the truck has an intermittent starting problem. The failure to start happens about 5-10% of the time. The motor will turn over fine, but but immediately stumbles while trying to start. Turn key off and then re-start attempt will be again followed by a bucking stumble. Some times the motor might try and run for 2-3 seconds bucking and stumbling. It is possible the problem happens more often when the truck is warm and has been shut off for 15 minutes or so. Once the problem happens it is very repeatable. It won't start again unless I wait about 30 minutes to an hour. Once it starts it seems to run very nicely. I have noticed some times when I go to successfully start the truck it might run roughly for the first 3-4 seconds bucking and sputtering a bit and then smooth out and not have an issue until the next re-start attempt.
The truck runs so nicely when it is running I doubt it is an issue with the plugs, air filter general tune up. Could it be an intermittent fuel pump issue? The next time it occurs I will check fuel pressure. Could it be fuel pressure regulator? Also tested by fuel pressure. ECU? The truck runs very nicely most of time that seems like a long shot. Crank sensor? Bad fuel? I did add some dry gas.
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So after work tonight I went to start truck it turned over fine but wouldn't start, when it finally did it barely ran and then it was fine, I had it b4 when I start it would turn over for a little bit b4 starting, would that be fuel pump?
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The Engine cranks over fine, but won't start. When it does start everything is okay and it runs good with no codes. I noticed that by taking the key out of the ignition, I was checking under the hood, and put it back in the truck fired right up. Also it has never done this to the second driver who has a different key. The truck runs fine at all speeds and loads, even when hauling twenty bags of wet mulch. It's a 2001, 4.6 L, RWD. Could the PATS Chip be failing?
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I have 98 f150 with 4.6 starter went so I put a new one on wich was a hassle and it tries to turn but just wont as if the motor is seized. I had been hear a loud howling sound from what I think is the ac unit and the ac line burst after trying to start. Would a bearing or something with the AC be enough to stop the engine from turning over? Or could it maybe be a wire connection problem? To me it sounds like a starter trying to start a seized motor but I cant see that my motor would be out it only has 190 000km and the oil looks good. but we couldn't turn the motor over with a ratchet? The truck had been getting gutless. I am stuck...
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My girlfriend has a 2003 f150 4.6lt pick up its a great truck most of the time. Problem is when the temp gets in the neg double digits it becomes very hard to start it cranks fine but doesnt want to fire. When it does fire it might stall a few times before it stays running. The last cold snap we had I replaced the battery and in the summer the starter got changed. I have heard that this model of truck are known for hard cold starts. I am just wondering if this is true and any other thing besides block heater. It is strange that my 89 gm pickup will start no matter what temp and I'm having problems with the newer truck.
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I have a 97 f150 5.4 4x4 a/c compressor and clutch. It won't let my motor turn over because the ac compressor is locked up bc the bearings are shot is there any way to by fix this until i get a new compressor and clutch....
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2002 F-150 4.2L. About a year ago, it threw the P0171 and 0174 codes up. After replacing all the simple stuff, I bit the bullet and replaced the lower intake gasket as well as the upper intake gaskets. Buttoned it all up, reset the codes and we were back in business. No issues, truck ran good. About 6-8 months later, the check engine light came back on, I check it and it was that pesky set of codes again, 0171 and 0174.
It still ran fine, but the codes were there, so I just drove it for a while (it's a company truck that doesn't get driven that much).
A couple of weeks ago while driving it, it acted very sluggish. You could mash the accelerator and it would just very slowly run up the speed. It never hesitated or missed, it just got very very sluggish. Checked the codes, no additional codes.
Then it began to stumble when you mashed the gas.
I put new plugs (old one's looked great, other than a huge gap), new wires, new coil pack and started it. Pushed the gas pedal, it just dies.
I look for obvious vacuum leaks and replace a couple of elbows for the PCV and it seems to run a little better. Enough so that I can drive it, but still not running right.
I ordered all the intake gaskets and new isolator bolts and spend Saturday pulling that apart. I didn't do the lower intake because the upper intake gaskets looked so good, I just don't believe this is a intake gasket problem. None the less, I installed the new gaskets on the plenum and upper intake, new isolator bolts, replaced a couple pieces of vacuum hose that looked cracked, started it back up, it ran as smooth as silk.
Convinced I had it fixed, I went for a test drive. Idling, it is as smooth as you could ask for. Pull up to a stop sign, wait, step on the gas and it chokes. Just stumbles and you can hear it almost backfiring and pushing air back through the system.
I've put new PCV, new EGR, new vacuum lines in several places, new upper intake gaskets, new plenum gaskets, new isolator bolts, and even new o-rings on the injectors, and I'm still getting the 0171 and 0174 codes.
With the diagnostics on, I can see voltage varying on all O2 sensors, so I assume they are working (none of them are reading 0 volts). It doesn't throw any other code up, other than the 0171 and 0174.
At this point I feel like I'm replaced every single thing ever mentioned in any 0171 and 0174 thread on the internet. Where to go next? 1 more point, if you very slowly push the gas, it runs fine, but any pressure on it, it bogs down and just stumbles.
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I can cold start my 98 f150 with the 4.2 and it runs fine. After you drive it for a while and turn it off and try to restart it, it starts then dies, it will do this until you rev up the motor to keep it running. I have to drop in gear and get going down the road and then it smooths out and runs fine. I had a mech check the fuel pressure at the rail and it was 19 psi. The book says it is suppose to be 35psi. He said my fuel pump was bad. I installed a fuel pump and it is still doing the same thing yet. What to check now?
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Vehicle is stranded on the side of the road (safely) and here's what happened. Driving (normal) 1/4 mile away from the house, motor shut down. Pulled off, tried restart. Motor turns over normally and all gauges work (temp/oil/volt). The only weird thing is that the O/D light on the end of the shift selector stays on even after pushing it on and off. I plugged in my OBDII reader and it will not link with the system. Yes... the ignition is on Is this indicative of a fuel, computer, electrical issue? or all the above. Worst case scenario is i have it towed to the shop tomorrow and they diag it. I don't have the proper tools to diag this.
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I come over from the old school forum (48-60) with a question about a new to me 1999 F150 XLT 5.4L, 4x4, Auto. Truck has ran awesome for a couple of days. Truck has in excess of 410,000 miles but don't let that mislead. I believe the engine has been replaced sometime along the way. Yesterday I was driving and it just stumbled and stopped. After sitting for 5 minutes it started again, stumbled and stopped.
Today I checked the following:
- Fuel pump/relay - both work
- Dropped gas tank and replaced fuel pump strainer and fuel filter
- Fuel pressure at rail remains steady
- No codes present and no SES/CEL on.
Could this be a plugged EGR valve or IAC valve? I have had similar issues on Tauruses but it always threw a code when it did. Could this indicate a cat issue?
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I drive an 03 Civic Hybrid. Twice, a week apart, while driving about 50, the speedometer goes to zero, then the power steering goes out and I lose power and momentum. The dash indicator lights go on like a christmas tree, engine still running, but car sluggish. I shut it off, and then get no power at all, not even hazard lights, and car won't start. With jumper cables, it starts right up and runs like nothing happened. IMA and check engine lights are both on, and have been since I bought it three years ago. In those years, my gas mileage has been consistent (42mpg) and no other funny business. Dealer won't work on it except to replace IMA and O2 sensors, which it has always coded for, and would cost the value of the car. What to do?
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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.
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My 2002 F150 Screw has been giving me issues when trying to start it for the last month. Sometimes it will start sometimes it won't. When I turn the ignition on the gauges all seem normal, the theft light turns solid then goes out, but engine will turn over but not start. Sometimes it will start if I leave the ignition on for 20 seconds then pull the key and try again. (this doesn't always work). I have disconnected the battery for about 2 minutes this usually works but not always.
Sometimes it will start first time with no issues. Once the the engine fires it runs fine. Another symptom is when I shut the engine off, pull the key and open the door, the chime telling me that the key is still in the ignition sounds. (but the key is in my hand)
I put a new battery in yesterday to rule that out and because the old one seemed to be getting weak. (starting issues didn't go away). I don't want to put 300+ into a fuel pump without being sure that's the problem.
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My 02 F150 4.6 has 84K miles on it, and started stumbling/hesitating during accellartion about three weeks ago. Before this problem started (about 2,000 miles ago), I installed a new fuel filter and air filter. Since I noticed the problem, I installed new plugs. The problem didn't go away, so today I checked the fuel pressure. At idle the pressure is 32psi with the vacuum line left on the fuel pressure regulator (30-45 is normal as per Chilton's), and 42 with the vacuum line off (40-50 is normal as per Chilton's). I also had someone else rev the engine so I could observe, and found that the fuel pressure went as low as 28 when the engine speed was quickly increased. The standing fuel line pressure is 30 (30 is normal as per Chilton's) Does this sound like a fuel pump problem, or is there something else that I'm missing.
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I just bought a used 2007 Hondai santa fe. 65K. Loved it until four times when I turn key to start the car 'stumbles'. Dealer finds nothing wrong. What I notice today is I did not have my foot on the brake. My 11 yr old Subaru started w/o (not good I know) so I developed a bad habit. So now I wonder if this is not a problem but rather a safety feature and I need to always have my foot on the brake at start.
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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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I've recently begun experiencing a problem with my truck dying immediately upon start up. It's a 99 5.4 and it will act like it's starting normally but then will idle down and die. If I gas it to 4000-5000 rpm it will eventually return to normal idle and run fine. At first it was once a week and then every day, usually upon the second start of the day but today it happened twice and I suspect it will become more frequent. What to check that doesn't involve a Ford Dealer?
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If I don't keep in the throttle immediately after start up it will stall a lot of the time. It doesn't do this every time or if it sits for a while but if I drive it and then stop off at a store or something and then go to start it back up it gives me this problem. I notice it idles about 3-4k RPM's when I stop at a light or something too.
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My son's 97 2WD Ranger with 2.3L, 5 speed, no a/c, basic XLT standard cab.
I was using his truck because my 93 Ranger was getting a new starter on it. I drove to work with no problems, then after work, it started just fine and drove a few hundred feet to a stop sign where it promptly died. I was able to start it again with some effort and drove to the next stop sign maybe a quarter mile away. Truck died again, but this time it would not start. Towed it home about seven miles and its in the driveway now. The previous owner had new Motorcraft platinum plugs and wires installed, new fuel filter, fuel injectors cleaned, all about 11,000 miles ago. My son has had it for about 6,000 of those miles.
It felt like it ran out of gas, but the gauge showed about 1/4 tank, and I put about 3 gallons more from a gas can into the tank with no change in being able to start it.
Here's what I've checked so far according to my Haynes manual:
Turned key and listened for fuel pump and it seems to go on just fine.
Checked fuses and they are fine.
Swapped around relays in distribution box with no change
Checked resistance at coil pack and it was about 1.7.
Checked resistance at one injector and it was about 1.7.
Checked inertia switch and it did not need a re-set.
I don't have the ability to check fuel pressure.
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I always have my car in DRL, and just noticed last night to today that it doesn't turn on immediately when I start the car, however it does seem to turn on a few minutes after the car starts rolling. I'm sure before it turned on immediately with the car. Maybe 12v going weak?
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RE: FORD PROBE GL (non-turbo). Last week suddenly car wouldn't start Thurs. night. Cranked but would not turn over. Heard click at ignition switch area when key turned to start position. (Although I could only hear one click from inside the vehicle with windows shut, I was told that clicks audible under the hood from standing outside.) Tried jump starting (from a good battery using proper connections) unsuccessfully, repeated tries several minutes apart, allowing longer and longer time to charge. About every third attempt, instead of cranking sounds, I would get silence, with only the click audible.
Temperatures decreased from approximately 50s to 20s when symptoms began.Battery is old but tests good/replace soon: 330+ CCA at 43 degrees, original rating CCA 530 (silver battery now at 7 years. Will replace, but garage did not have required size 56). At that point, the amps gauge read at the low end of the normal range (and today it read mid-way in the normal range).Had car towed to garage on Friday. Mechanic looked at on Saturday and decided it was the inertia switch, which he said had "tripped".I watched video for technicians on inertia switch but it shows on newer Fords. Mine is not located at the kick panel and does not have a red button on top. I am not certain from my experience whether the reset button would actually be in a different position when tripped or he merely surmised that is what had happened, despite my telling the shop manager that I had not so much as bumped a curb. Also, the trunk was not slammed or even opened prior to the car not starting.
Car presumably started fine at mechanic when they pulled it into the garage to put air in tires and back out to the lot, as well as when I started it to drive home on Sunday. However, on Tuesday it would not start. Just in case, I depressed inertia switch reset and tried cranking again several times, giving it some gas, until I was actually pumping it vigorously in desperation as a last resort (several seconds turning key each time), and on about the 5th try, the engine began to catch just as I was releasing the key. Reset the inertia switch one more time (just in case), and after a couple more attempts, it finally started, but when I was going in reverse to back out and then putting in gear to start out in first gear, for about 15 seconds total, I heard a bizarre loud, fairly high-pitched whistle/whine type of sound that seemed to come from under the hood coming through the central area of the dash where the radio is located.
Drove about 5 miles to my job, and about 2 hours later was able to start the car on the first try. Lately usually driven relatively short distances of 2-4 miles, with a longer drive of 11 miles broken up into 6 miles + 5 miles on the return trip the night before this started happening.
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