My van stumbles & hesitates when I am gradually accelerating up a hill. It does not happen if I accelerate quickly or on level ground. It only happens going up hills slowly. It can be very violent.
View 1 RepliesMy 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.
View 10 RepliesFord Focus 2004 manual 150K miles. Most days the car runs fine. Other days it will start and run until it warms up, then stumbles or hesitates at speed. When this happens the headlights and dash lights are also flickering. Sometimes i hear a clicking sound behind dash, left side. I have the sure cure: turn the heater fan to high. This works every time. When the engine is hesitating, i turn the fan to 4-high, the engine smooths out. Turn the fan down, engine again hesitates. Hesitates at 3, worse at 2, worst at 1. It seems to need the extra load.
But after few minutes of high heater fan, the alternator light comes on. I flick the heater switch down, endure the hesitation for a few seconds, the alternator light goes out, engine still hesitating, flick the fan to high, engine smooths out. A few months ago i could get it to fun smoothly with the fan on 3, didn't need 4-high. Now seems to need 4.On the days when it is always running smoothly, the heater fan can be on any speed, the alternator light does not come on.
Next few days or even weeks the engine will run smoothly, no hesitation, with the fan on or off or any setting.
The car has been to three shops in past year, one of them a major Ford dealer, who kept it two weeks. The problem has been diagnosed as battery (replaced), Battery connections (checked), plugs (replaced), fuel pump controller (replaced), fuel pump (replaced - ouch!), alternator (replaced twice - ouch twice), grounds (checked). Every time they "fix" something the car runs ok for a week or so.OBD shows P2004 (intake manifold runner stuck) but all agree it can't be the problem.
There have been a few times when i flicked the heater fan to high that all the dash lights died, fan went off, headlights off, turn signals didnt' work, but the engine ran smoothly. Not so good on the highway at night!There have been a few time, not recently, when the car wouldn't start. No dome lights, no dash lights with key turned to ON, no clicking or starter with key turned to START. It acted as if my battery was missing. The cure was to turn the headlights on. All normal after that.
I have a 2001 Accent, manual transmission 1.5L. The lady who had it before me overfilled it and stuffed the charcoal canister. She had this replaced, but when I bought it she reported that it still had a fuel issue immediately after refueling. She said it would stall and run rough and hesitate.
After I bought it I took it to refuel and confirmed the problem. I had read that the ECU may be trying to draw fuel through following refueling, but the new canister might be messing something up. She used to only drive it commuting distance in a city, so I took it for a long drive. Running at steady cruising state for a prolonged period seemed like a good idea, to allow any ECU learning. This partially fixed the problem! Now, most of the time, I can leave a fuel stop without a 20km drama before the car settles down, although the problem hasn't entirely gone away and it still does play up sometimes.
There's a more pressing problem which may or may not be related, however. When launching from idle, the engine goes through this 2-5 second hesitation of no power at all. If I rev up before letting the clutch out it's ok, but there's a certain minimum revs needed to avoid the problem. This is killing my clutch, and if I get it wrong it sometimes leaves me in the middle of a busy junction with no power for an uncomfortable period! During the hesitation, I've found the best way to force it is to put clutch back in and go full throttle. After 1 second or so the revs come back. The problem is much worse when the air conditioning is on.
So the clues are:
1. the previous charcoal canister issue
2. the full throttle thing might indicate something with the TPS
3. the worsening of the problem with the a/c on
Things I've tried so far...
1. prolonged cruising; seemed to improve things after refueling but overall fueling issues not fixed.
2. disconnected the battery -ve and applied brake light circuit to drain ECU capacitor, then left for any power-hold relays etc. then reconnected battery and took it for a normal drive for 30 minutes or so. No effect.
...and things I've yet to try (all gleaned from searching this forum)
1. checking / replacing plugs and HT leads
2. checking / replacing o2 sensor
3. checking the TPS plug connections. Checking the sensor itself sounds expensive - would it involve more than standard OBD?
4. checking vac hoses, in particular the hose which draws from the cannister
5. checking alternator (not sure how); the worsening of the problem with the a/c on could indicate low power getting to injectors etc? (bit of a wild guess)
In a former life I was a diesel engine calibration engineer, so I know the tricks which manufacturers can put into ECUs. What I don't know is the tricks specific to this car.
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.
For the last 2 months I have been having an issue with my 2007 Passat when speeding up BUT only up hills. I have brought it to the dealer over a month ago when it was really bad on highways and it barely speed up to 60mph. So I went and got new 4 brand new tires with an alignment. Problem was still there but def. improved the, I guess I really needed new tires! But the hesitation still there, so I went again to VW and they didn't get no error or fail messages when they test drove it.
But I knew my car did not sound like that 3 months ago. So I brought it again and went with them for a test drive and the mechanic felt the hick up speeding up at 60-70 mph as well, you could even see it on the speedometer that it set back for a sec. when accelerating at 60mph but after 70 and 80mph it is riding smooth. VW mechanic only saw a high air intake when it happens and believed it was the engine speed sensor that was failing.
Yesterday I went to the VW dealer for the 5th time and they have it again all day, test drive it and now they say yes it is still doing it. Diag. laptop still shows no signs or fails. BTW, I don't have any start misfires like usually carbon build up cars get!! I did my research online but I see no other Passat's doing that kind of thing. I just don't want to continue driving it and one day my engine just cuts off...The car is balanced and just got aligned, and my steering wheel is not shaking while it happens either. I feel a little hick up from the floor/gas pedal.
My truck recently has been giving me the issue of wither having no boost , bogging down as its trying to excelerate , then going into overboost. It idles fine , i have cleaned out the egr . I'm at a complete list on what to do at this point the truck is a 2007 F250 6.0l
View 4 Replies2002mazda protege5,2.3 ltr engine.had the timing belt changed, then the problem started after the belt was replaced.took back- scan showed short in #2 cylinder and vacuum code.they fixed coil problem for #2 cylinder but vacuum code went away.once rmp get above 2500 accelerates o.k.hesitates when taking off from stop sign, etc.could vac hose be missing somewhere?seems to act like it floods when taking off.does vacuum control timing advance or gas/air mixture?
View 5 RepliesI have a 1998 Jeep Cherokee with a straight 6. Lately I have been having trouble with hesitation when I accelerate. It happens at all speeds. It is a stick shift, and as I push in the clutch pedal, the engine races a bit and then as a let it out the car hesitates and/or bucks if I don't give it a shit load of gas. Also, if I let off the gas completely and then try to accelerate quickly it will pause and buck unless I do it really gradually. This problem is intermittent, so I am thinking it might be something with a sensor. Also, if it stalls out completely, restarting the car requires me to hold the gas to the floor. I have already replaced the camshaft and throttle position sensors. Not sure what the deal is.
View 1 RepliesI have a 2000 Saturn sl2 (automatic 85,000 miles) and recently, I can feel the momentum of the car stop for a split second. The hesitation isn't occurring when the transmission is shifting between gears but, when I'm just at a normal speed or accelerating. The fluid is new and at the right level and there's no change in the RPMs (it doesn't rev up or drop like I would expect) and no weird noises.
This is my fourth Saturn SL and I love em but, I have a feeling that this car has had a more interesting life that the carfax printout indicated. Is carfax reliable?
1994 olds 88 royale with 3.8 sometimes hesitates or "bumps" when accelerating. sometimes it seems like the tranny is slipping, but other times it seems to feel like poor firing or slight misfire with hesitation. when at highway speeds of +50 it runs fine but occasionally bumps or seems sluggish if i rapid accelerate or speed up to pass. do i have a tranny problem or poor performance or emissions problem.
View 1 Repliesi have an 88 volvo 240 wagon with 89K miles on it... it's been passed down through the family, is in great shape and is a joy to own. i have always have it serviced at the volvo dealership and recently had a bunch of work done to it including complete lube, oil and filter change, replaced the radiator overflow cap, replaced a leaking valve cover gasket, replaced the oil pan gasket, replaced the rear diff gasket and added oil, and replaced the sway bar links (it was an expensive visit).
to my dismay, on the way home, accelerating hard up a hill, something under the car started to rattle and black smoke started coming out of the back of the car. i took it back to the dealership and they replaced a leaking seal that they said was the problem, on the way home, same thing with the rattle and smoke happened on the same hill... maybe just stop driving on that hill, right? so i took it back and they changed the oil again (the oil levels were a bit high) and said they couldn't find anything wrong... drove the car home and seemed not to have the problem (though i did take it easy on the hill).
so today, i take the car out for a drive (usually just drive it on the weekend), and accelerating hard up the same hill i get the same rattling and black smoke that continues until i let off the acceleration. by the time i get home (a couple blocks later), it's like nothing ever happened.
Is it safe to drive as long as i don't accelerate hard? Never had this issue before all the work was done, kind of seems like i should take the car back to the dealership, but this would be the 4th time for the same issue...
my 88 camry will start and idle fine however whenever you attempt to accelerate the vechicle the car trys to stall and hesitate badly and will not move. i have changed the fuel filter the spark plugs and plug wires i cannot figure it out. also this started out of nowere the car was driving i had been driving for about ten miles stopped at a red light and that is when the car started doing this.
View 9 RepliesI recently purchased a 1997 Rav4 (3F-SE Engine) with 162000 miles. Overall, it is a great car. The only problem (besides a clutch, which can wait) is that it hesitates/bucks between 1500-2100 rpm while accelerating. This happens usually on a shift change from 1st to 2nd, or while in 2nd and after decelerating to make a turn. This only happens after the engine has warmed up, i.e. the temp gauge is above 25%. When cold, there is no hesitation at all. It just passed emissions testing. Check engine light is off. I recently replaced the TPS (and adjusted it properly), with no change in symptoms. This car does not have a MAF sensor.
View 8 RepliesI have an 08 awd honda element w/ 70k miles-last 2 yrs my element has had slight hesitation when slowly accelerated to about 30 mph and seems to 'balk' in the 25 -35 mph zone.No problems noted when accelerating quickly in that zone and car performs well otherwise. I have changed air filter added dry gas in winter but the problem is year round. I use generic gas.
View 1 RepliesI have a 1991 Audi 100 that is flawless and paid for. 215,000 miles and doesn't leak or use a drop of any vital fluid. It does have one problem: While under load and accelerating from a dead stop, about 75% of the time the engine hesitates as if it is not getting any fuel. You step on the accelerator, get no response for one second and then off you go, no problem. On occasion while accelerating from a dead stop, the engine will quickly cough, pop like a backfire, and then catch. I have replaced the fuel filter, and through accident inadvertently found out that I seem to have excellent fuel pressure. While at speed, I seem to have little or no problem with instant acceleration when the accelerator is pressed.
View 1 RepliesI recently bought a 2004 Hyundai Sonata 4cyl with about 65k miles. In the past few months I've noticed that it likes to sputter and hesitate at times, mostly in lower gears when I'm not accelerating hard. At highway speeds it's mostly fine. It's also fairly random - some days it's really bad and others it's fine. Also seems worse when in reverse. I don't think the plugs have been changed so that's one idea, but I'm wondering if it's a bad fuel filter, exhaust manifold leak or something else. It's not throwing any codes (and yes the light works) and it has never stalled completely out.
View 4 RepliesI have the light engine on - and my mechanic has informed me that the O2 sensor on bank one needs to be replaced. I need to understand if the lost of power when accelerating the car can be directly related to the O2 sensor or something else. The car hesitates and takes long to switch gears on my Auto tectronic trany.
View 2 RepliesIts the 5.4 ....its been an ongoing problem...first it wiuld happen once a month starting maybe a year ago. Turn the key off and try again and it would start up easily. Gradually became more frequent...maybe a couple times a week now and sometimes taking more than one attempt. It died on me while driving last week...started easily again. Today after driving i parked it and a few minutes later it would not start even after 10 or so attempts....waited 10 or so minutes and started right...killed it and restarted 5 times easily. Brought it home killed it and it would not restart.
Now its starting again......so i cant troubleshoot something that is not working. I ruled out fuel pump/regulator because it is either running good or not at all and also it would not start immediately after killing it. There should be engage pressure in the lines to do something but its either a start or no start situation. Its not showing codes either....so I am guessing that rules out sensors....? ......so i guess something is causing a no spark or a no fuel inj. Pulse......... I have a cam sensor i bought a few weeks ago and never put on trying to aviid being stranded.
I live full-time in an RV which results in very bad condensation building up in the cab and over the past year, the ignition system has gradually got more and more stiff.At first, it was noticeable that it did not spring back from "start" to "run" (the airbag light remained on and the fan/indicators did not work) but I just had to tweak it into the right position.
This was mainly an issue when starting from cold.Then, after a long drive with the heater on, it would not turn off. It finally took a wrench to turn the key off. Leaving off the heater seemed to work but it gradually got worse and it got more and more difficult to turn it on.I finally replaced the key cylinder but it made absolutely no difference and now the key physically will not turn. I am now sitting in a vehicle with no propane and full waste tanks.
So, I've been having cold start issues for a couple of years now especially when temps get below 25 or so. It started with virtually no issues until temps got into the 20's but got to the point this year where it run a little rough at startup even in the summer. Once ECT gets up around 140* it runs pretty good.
I took it to a diesel shop last year and was told I had 1 bad injector and a bad glow plug. I couldn't afford to do the work, so I waited.
Now after researching this site, I'm more inclined to think it may just be the FICM. I've seen scangauge numbers in the low 20's up to 48.5. On cold morning FCM will usually start in the low 30's and gradually work up to upper 40's. The batteries were both replaced 2 years ago, but I probably should give them a load test. The alternator voltages vary from 11.0 to 12.5 when cold and 12.5 to 14 once warmed up. I have noticed that the AC blower will slow down a little when I sit at a red light, and then pick up again when taking off. I don't notice it with headlights or anything else.
According to Bismarc's spreadsheet, alternator numbers seem to be in the acceptable range, but I don't want to get a new FICM and fry it with a bad alternator. I can get the alternator or the FICM now, but if I need to do both at once I'll need to wait a bit longer.