Engine Running Rough When Accelerating

So it seems that the trouble appears when accelerating hard after stop and go driving. The bike sputters on acceleration and runs rough under load. 140000 miles. Run a vacuum pressure check (AKA Lower than atmospheric pressure test). It's 10 years old. I thought no big deal. It bucks and kicks and shudders, especially when trying to go up even mild slopes or if I accelerate the slightest bit. A properly functioning idle should feel smooth — no bumps or skips. Running Lean You may be running lean (too much air in the A/F mixture) if you are: 1. Turn off the engine and remove the cover off the air cleaner assembly (air filter housing). Dropped the boat in the water yesterday, she started right up, but under acceleration the engine is cutting out and has reduced power. Changed wires and went to autozone and had codes checked. It isn’t as smooth as it was before. 11 Causes of a Vehicle Losing Power when Accelerating. Why is the engine bogging under acceleration? I recently managed to get the moped running properly, albeit for only a short time. Compression is 215-220-220-225. I just changed the spark plugs, but it didn't help. Once I get it up around 1500 to 2000 rpm, it smooths outs and runs OK and doesn't make excessive noises. 6 Engine Running Rough the Check Engine Light is not on « Reply #11 on: October 13, 2011, 08:42:06 pm » The check engine light never came on , I used a code checker and P0307 (number 7 cylinder miss) and P0316 miss detected below 1000 RPM , I installed a new plug (Motorcraft) and a coil , all is well , it runs fine. Acceleration/cruise The engine stops unexpectedly at the beginning of acceleration or during acceleration. It didn't run perfectly before, but one day it just seemed like something fucked up and it's been running badly ever since. Sometimes we experience an annoying hesitation or stalling when we are cruising in our cars and decide to accelerate either slightly or harder. Normal engine maintenance schedule followed. Then even under light acceleration the engine runs very rough, shudders and lacks power. So it seems that the trouble appears when accelerating hard after stop and go driving. An engine cylinder misfires when it is unable to efficiently burn the air/fuel mixture in the combustion chamber. no linkages have been adjusted or anything like that, everything has been left exactly the same as when I got the cars, apart from changing the timing chains, guide rails, oil lines, motor mounts and basic maintenance. The engine starts, runs about 3 minutes and then starts stumbling, backfiring, and eventually will stall out. Rough running and poor acceleration but no codes?! – 30-08-2019, 12:48 PM Mk4 1. I have yet to get a check engine light, so I got no codes to work from. My engine runs ok when idling or accelerating at a moderate rate. Try this first, it costs. My car is idling and accerlating very rough. I have been told that some garages put the wrong spark plugs in and causes this? I been told they need to be twin ground electrode plugs? Please give any suggestions thanks. Just bought a 2000 xterra with 84k miles. 89K miles, and for the past month, it has been having several different issues, such as engine surges, rough idle and acceleration and the service engine light has been coming on. I have checked for Vacuum leaks and didn't find anything obvious. car would shut off when wires touched. On Thursday after filling the tank with 93 octane it started to run rough after a few miles (it had 93 in it from when I bought it) and a few minutes later the engine started to bog when I hit the accelerator. Mechanic saw knock code and lean code first time. The idle is very rough after coming to a stop. Then it got very sluggish again. I have checked for Vacuum leaks and didn't find anything obvious. I get the same P0303 code each time (misfire cylinder #3). NOTE: IF YOU HAVE 0420, 0430 ERROR CODES WHICH TELL YOU THAT CATALYTIC CONVERTERS ARE NO GOOD ANYMORE, IT MEANS YOUR ENGINE IS BURNING OIL KILLING CATS, SO NEW CATS WILL NOT LAST IF YOU DON'T FIX INITIAL PROBLEM WITH VALVE SEALS!! CATALYTIC CONVERTERS CAN EASILY LAST 300-400K, AND THEIR FAILURE INDICATES INTERNAL ENGINE. Then a couple days ago to add to the problems, in the midst of driving it started vibrating at red lights and running pretty rough, it also now has a big loss of power with any type of acceleration, not just up hills anymore. If it runs better than the choke sensor is bad. seems to have a litttle more punch now. The last owner confirmed he replaced 4 injectors. A few days later after getting up and running, the service engine light came on. White smoke out the exhaust when the engine is cold and the ambient temp is cool or cold is normal. If it is cold, it fires right up, but if it has been running and i try to start it, it is almost impossible. At idle it sputters and sounds more like a little boat engine to me. there is a good chance the vibration isnt coming from the engine itself. The only code is P0300. Having a hard time getting the engine started, 2. At idle it has a slight miss, and under load any sort of load or while accelerating through mid range RPMs, it runs like absolute crap and will even feel like a shutter at times. That apparently caused that cylinder to have no compression, hence the very rough idle condition (engine was only running on 7 cylinders). Normal engine maintenance schedule followed. Opel Corsa 1. Sometime dirty parts can also be the root cause of a rough idling engine. I gave it full throttle in neutral (standard) and it reved to about 4500 then bogged down to about 1500 spitting and sputtering with the pedal all the way down. o Trac/Off light is coming on at same time • The exhaust smells like there’s too much fuel. Can someone please help. 3 Runs rough when engine is cold runs real bad choppy acceleration until it gets up to temp. The problem may involve an annoying change (up/down) of engine speed while cruising at a steady pace, a low drop (or even cut-out) at idle or when approaching a stop, a wild high engine speed of several thousand rpm followed by a drop to near zero, etc. Other considerations. The only code is P0300. This has been gradually getting worse in the past 2 months. What Would Make a Car Run Well While Idling but Rough Under Heavy Acceleration? A faulty oxygen sensor can cause a car to accelerate roughly while under a heavy load. Rough idle shakes when accelerating loss of power So I haven't posted on here much but I need some help. The oxygen sensors main purpose is to manage the air/fuel ratios inside of an engine. Well today the engine light turned off again and the car feels like its running normal again. The fuel burns and powers the car. 67 Answers. It ran okay (not great) when the t. It also has a VERY slow acceleration and then it will just jump and go. does this make sense or is it probably something else?. I've had it to the dealer twice and they say it's normal. Various components on the car are actuated by engine vacuum. Acceleration is much improved but idle is still a little rough. com Engine smooth at idle rough at acceleration was created by LeoTheLion89 with my daewoo i have noticed 2 things 1 the engine is smooth as it is idle but runs rough once i give it gas 2 It will run smooth at idle until it warms up then it will run rough at idle and MORE rough at acceleration. Why is the engine bogging under acceleration? I recently managed to get the moped running properly, albeit for only a short time. It usually indicates that your vehicle's engine is misfiring, which could severely damage engine TB, and catalytic converter. Popping, hesitation, rough running - just can't fix it!. It didn’t happen when the truck was cold but would show up when it had warmed up. If the oil is extremely dirty then yes it can and will cause everything you say plus cause massive damage to the engine from the. Engine smooth at idle rough at acceleration was created by LeoTheLion89 with my daewoo i have noticed 2 things 1 the engine is smooth as it is idle but runs rough once i give it gas 2 It will run smooth at idle until it warms up then it will run rough at idle and MORE rough at acceleration. IGNITION TIMING Most engines (except diesels) use an electric spark to ignite a fuel/air mixture. No difference. Engine Stuttering / Acceleration Vibration. After the engine warms up idle speed will increase and the engine may smooth out (although acceleration may have some hesitation until the engine gets real hot. what should I do. I have been told that some garages put the wrong spark plugs in and causes this? I been told they need to be twin ground electrode plugs? Please give any suggestions thanks. 0 XLT and let me just say I've tried what I could think of and luck just hasn't been on my side. If it is carbureted you may have a stuck needle valve under the float. If a valve spring has broken or a cam lobe has worn down, it will cause the engine to misfire and run rough due to the loss of compression. It work for me I'am not sure why, but it works. Rough idle, low power on acceleration, backfire on acceleration along with black smoke, hesitation Out of the blue the 75 FJ40 started this behavior after starting it up two days ago. Land Rover Freelander 2 Lovers 101 things you (possibly) didn't know about your Freelander2. I just bought my first Jeep. And when the engine runs rich, it’s exact the opposite: too much fuel in the combustion chamber and black smoke comes out of the rear exhaust. Though typically the engine evens out a bit when up to constant speed ( highway ) there are times when its in a bad way when I have to stop the truck because. four cylinder engine with a webber 32/36/AV carbureter. When I was driving up a hill on my way back, the service engine soon light started flashing; there was no sound that accompanied this nor was there anything that I had ran over. Neither are high hour machines (700 and 600 hours respectively). At full highway speed (120 km/hr or 75 mph) the engine seems smooth and the car revs at about 3600 rpm. I can turn key off for about 10 seconds and the restart. Also, when I say the engine runs rough, it isn't the same as miss-firing. LTFT stayed at zero the whole time. Many times I have helped people that were confident there fuel supply was good, and when they put a gauge on it they find the fuel pressure was the problem. We have a 2006 Dodge Charger. When it does the car will start having a really rough idle when stopped. There are several common causes of engine vibration in a car, and they all result in shaking and noises that can be quite alarming and sometimes scary. If operating correctly, at all the various engine speeds and loads, computer should be able to balance out the short term trim around zero with a long term trim. Rough idle, low power on acceleration, backfire on acceleration along with black smoke, hesitation Out of the blue the 75 FJ40 started this behavior after starting it up two days ago. While driving car suddenly began to dramatically lose power and would not accelerate as I give it more gas. Let's run through a few possibilities. One of the most common problems is likely a rough running or poorly idling engine. The fuel burns and powers the car. When I got it to run it seemed to run okay at wot but when I throttled down it seemed to be missing and running rough. Engine deposits are another reason causing black smoke from the tailpipe. This evening I changed the pugs after I gaped them to. I was driving my 2000 7. Mechanic saw knock code and lean code first time. I have a Vauxhall Corsa 1. I've got a 2005 Dodge Ram with the 4. Why does my car accelerate slowly when I press the gas? the car is moving, but it’s ridiculously slow and you can tell that the engine is struggling to keep up. I did have a fouled plug some months back (was running too rich), and after swapping it everything was fine. Page 1 of 2 1 2 Next >. It studders! It will only stop doing this when I release the gas and then gradually press it back down. of course, u should run a scan if u can afford it. engine was running fine until 7 days ago it started a slight stumble upon acceleration. with the 420, I ended changing the fuel distributor because it was idling rough, but now it only has this acceleration problem. By the time I am at work it is running ok still a bit on. The engine itself can also be the cause of noises when accelerating. Try this first, it costs. Eventually, it warmed up and ran without using the pedal, but there is a distinct spluttering sound and loss of power when accelerating through all of the gears. I have an 01 Legacy and have been having this issue for the last year now. But when I accelerate out of the parking lot it hesitates and really sputters. Open the hood and inspect the V-belts when the engine is off and running. Problems with idle speed—things like slow idle, fast idle, rough idle, or stalling after idling for a few seconds—are symptoms that something is wrong with your engine. I suspected it was gear compensation pulling timing that was causing it so I turned that off, but it didn't seem to help. Runs rough while under load only. It sounds like just a tune up will help a little but it sounds like maybe theres a knock in your engine or your exhaust is running a little rough. I've checked the fuel pump and it seems to be getting plenty of gas. Engine smooth at idle rough at acceleration was created by LeoTheLion89 with my daewoo i have noticed 2 things 1 the engine is smooth as it is idle but runs rough once i give it gas 2 It will run smooth at idle until it warms up then it will run rough at idle and MORE rough at acceleration. 146,000 miles. The Jeep will start right up but will idle very rough. She made about a five minute stop and when she restarted the vehicle, no problems at all. It work for me I'am not sure why, but it works. Then it got very sluggish again. N/A: Cracked distributor cap. After the engine warms up idle speed will increase and the engine may smooth out (although acceleration may have some hesitation until the engine gets real hot. Engine hesitates, rough idle. Both conditions can cause a P0171 lean code, rough or unstable idle and sometimes even a stalling condition. After all this work, my altima is still idling rough in gear. I am looking for common solutions, since the truck refuses to give me a check engine light, so i cant run a diagnostic on it. Feels like driving over reflector bumps in middle of the road. LTFT stayed at zero the whole time. I have changed all the old vacuum hoses, connections, and inter hose units. A passenger car will usually idle between 600-1000 RPMs. could it be the injection? headgasket? oil? without taking it to a mechanic what could be done. Out of 23 different cars and trucks I've owned this is probably the worsy running vehicle I have owned. Your car's engine needs both fuel and air to do its work. Pay attention to any jerks or stutters, particularly while accelerating under a load, as a symptom. My 59 TR3 runs fairly smooth at idle. Your engine can rev up ok unloaded but when it's loaded (in gear) you are stuttering. This could happen during acceleration, driving downhill. When performing a hard acceleration, the truck suddenly looses power, the check engine light comes on, and once returning to idle the engine runs rough and won't accelerate. 1992 lexus ls400 has low, rough idle, extremely slow acceleration. To accelerate, I have to keep throttle below 30-ish percent. Hi guys, I have a 1978 280z that i recently picked up. Also, when I say the engine runs rough, it isn't the same as miss-firing. car is giving cel code engine - 25, 26, trac code - 11, 51. But the idle remains rough, and you can feel a vibration when accelerating, even a little. i have replaced the PCV and grommet, car running improved slightly, cleaned idle air control. Insufficient burning inside the engine will make the car hesitates or jerks when driving. growling noise when accelerating hard ('07 3. When I try to start it, it doesn't start very well, really idles rough, and when I give it some gas (not even under load), it stumbles, boggs, and backfires a little before it picks up rpm. Its a 1999 X1 Lightning with 4092 miles on it. Its only at idle when it does it. There are several common causes of engine vibration in a car, and they all result in shaking and noises that can be quite alarming and sometimes scary. I parked it in the garage, today I started it up and it is running rough, backfiring and low on power. The problem started without warning. Plugs are 2 yrs old, fuel filter 2 yrs old and air filter is new. Sometimes I can see black smoke from exhaust (unburnt fuel). Within about 3 minutes, it would not go beyond 10 - 20 mph, jerks and stumbles as if trying to accelerate but unable to, runs rough, and NO check engine light. N/A: Faulty spark plug. Open the hood and inspect the V-belts when the engine is off and running. So it seems that the trouble appears when accelerating hard after stop and go driving. We have a 2006 Dodge Charger. I'm thinking fuel pump now. Acceleration was poor too. Treating with Stiction Eliminator will clear out all of the stiction gumming your injectors. It has a yellow colored ring handle and “engine oil” is stamped on the ring. i have replaced the PCV and grommet, car running improved slightly, cleaned idle air control. Not as bad since the engine mounts but here's another clue as to what might solve some symptoms. After all this work, my altima is still idling rough in gear. If the idle changes, you have at least narrowed down the problem. That, combined with the poor power and erratic idling probably suggests that I am not getting a rich enough mixture. It idles very smooth. For the past few months our check engine light will come on periodically. I have checked for Vacuum leaks and didn't find anything obvious. The engine itself can also be the cause of noises when accelerating. almost like it wants to stall. Worst after stationary idle, but also after moving at low to medium speed with closed throttle and then accelerating. I pulled the code for the check engine light and got: P0171 - System Too Lean (Bank 1) OBD-II Trouble Code: P0171 System Too Lean (Bank 1). Power generally holds steady on the freeway, but every now and then I'll still have those episodes where it just suddenly starts to stutter and lose power. I pulled the code for the check engine light and got: P0171 - System Too Lean (Bank 1) OBD-II Trouble Code: P0171 System Too Lean (Bank 1). My car is idling and accerlating very rough. 3 Van was running great then while driving down the road it was as if someone flipped a switch. Engine runs rough at idle smooths out when driving. Find a code reader and find out WHY the check engine light is on. I have a 1994 GMC suburban. This evening I changed the pugs after I gaped them to. The engine could seem to rev up and down on its own at idle, but it’s more likely that it will simply rev up abnormally and stay there at idle. What Causes a Car to Run Rough? Credit: Jordan Siemens/Taxi/Getty Images Reasons for a car running rough can include problems with the engine temperature or oxygen sensors, bad hoses, ignition system or timing problems, clogged air or fuel filters, and faulty spark plugs or fuel injectors. told to run seafoam thru it and should clear up after running three or four times. I can even hear the engine working harder sucking air or something. Your car's engine needs both fuel and air to do its work. When the engine is started cold, the engine temperature sensor sends a signal to the DME control unit to provide a richer mixture. had engine wire replaced and it was fine for a week or so while it was dry. Hi guys, I have a 1978 280z that i recently picked up. There are many moving parts, and all the parts need to move at the right time in order to make the engine run properly. Pressing the gas does not help at all. We have a 2006 Dodge Charger. If the engine runs good at 3000-4000 rpm but stumbles elsewhere, the correct main jet is being used, and the problem lies somewhere else. My engine runs ok when idling or accelerating at a moderate rate. Rough running and poor acceleration but no codes?! – 30-08-2019, 12:48 PM Mk4 1. She ran fine for the longest time. When it does the car will start having a really rough idle when stopped. You need to look for something temperature related. Engine bogs and will not go beyond a certain RPM. Honda's acceleration gains with its revamped MotoGP engine are not yet consistent, reigning champion Marc Marquez feels. For the past few months our check engine light will come on periodically. For about a year and a half I have an issue with jerky acceleration at lower speeds. Run some Redline S1 with a half a tank of gas or more and change engine oil and filter in a week or less. 6 thoughts on " Running Rough?? Check engine light? No Problem!! " Brooks December 16, 2014 at 11:11 pm. When one or more cylinders stops firing, the power cuts, and the vehicle hesitates under acceleration. Car was driving fine. It was hard to restart and I had to press the gas pedal slightly to keep it running and then a few minutes later it recovered and drove normally again without stalling. Took my 2003 Sportsman 500 for a drive and it worked really good. Re: 1988 350 TBI idles funny, stalls when put in gear, and accels rough Fixed! After rebuilding the fuel pressure regulator, new fuel filter, plugs and wires, I finally dropped a new fuel pump in and seems to be running like a champ. It depends on what you mean by “old”. Good idea to check fuel trims and O2 sensor adaptations, it will tell you if you have any vacuum leaks, which will make your engine run very inefficiently, shaking etc. When an engine is running at idle speed, it generates enough power to operate systems such as the water pump, alternator, and power steering — but not enough power to move the vehicle itself. It seems as if ur fuel pump is weak. Since then, I have sprayed Johnson/evinrude engine tuner into the intakes, changed prop and added fuel stabilizer. sometimes, but it would not rev above 2500RPM, and then it would then smoke excessively if you tried to keep accelerating and proceed to kangaroo down the road in a cloud of smoke. it started to run rough when it rained about a year ago and then the engine died going 55 mph when it was raining. Most carburetors use a piston or diaphragm type pump. The engine itself can also be the cause of noises when accelerating. Once its been driven a bit you can sit with it idleing for as long as you want and it wont stall and pulls away fine. even headers, to manifold, to a crank in your engine. Had him install oem MAF sensor. Also, sometimes when accelerating, the car stutters. If you got white smoke coming out the tailpipe during acceleration when the engine is warm, that’s another story. A properly functioning idle should feel smooth — no bumps or skips. It’s just water vapor, a byproduct of the combustion of gasoline. Of course, a misfire while accelerating meant the Toyota V6 got even slower. It was a consistent noise. But when accelerating or pulling uphill, it becomes sluggish and misses, causing the truck to shake and sputter. I think it may be ignition, timing, or carburetor related. Air filter. Cranked it up and got two blocks, then when I tried to accelerate it stalled. The best course of action is to take your vehicle to an Omaha auto service professional, but here are a few things it could be…. Opel Corsa 1. The engine has more power, is more responsive, and generally runs pretty smoothly, but it still stumbles and even backfires slightly on acceleration. of course, u should run a scan if u can afford it. Rough Idle. Test the engine's performance through the range of 1000-4000 RPM, paying attention to steady throttle position through this range. But when accelerating or pulling uphill, it becomes sluggish and misses, causing the truck to shake and sputter. Just bought a 2000 xterra with 84k miles. Other considerations. Starting up, the car runs fine; very smooth idle. 8L manual has been running rough and hesitating on acceleration. When it does the car will start having a really rough idle when stopped. Engine hesitation, almost by definition, usually goes back to a misfire in one or more of the cylinders. 3 Stumbles on acceleration, rough running Problem Diagnosis Car Forums 4. Another strange thing caught my interest. The engine may only misfire and run rough when cold but then smooth out as it warms up. It didn’t happen when the truck was cold but would show up when it had warmed up. I had a similar problem about a month or so ago - check engine light came on and the car was running rough. Hi All, Ok so my car has been running fine and lately (last couple of weeks) it has developed a running issue where it idle's poorly (fluctuates back and forward) and the last few days, and especially today it has been running quite rough (coughing and spluttering, not wanting to rev properly hope this makes sense) and has progressively gotten worse today. Worst after stationary idle, but also after moving at low to medium speed with closed throttle and then accelerating. If it will help here's the numbers from the tin shroud - 126T02-0290-B1 10032658. had engine wire replaced and it was fine for a week or so while it was dry. My 1996 Tacoma 2. Rough idle, hesitation on acceleration, raw gas smell, rough running? Now I have another question, totally unrelated to the vehicle and problem that I posted yesterday. Per Pony Carbs timing instruction initial advance was at 20 degrees, mechanical at 18 degrees and John told me on the phone to add more initial advance but this seemed to make the. Sometime dirty parts can also be the root cause of a rough idling engine. Then it got very sluggish again. Loss of power, backfiring, not sure what to do. Advertisement Proton Prevé – our first impressions of the IAFM+ and CFE April 5, 2012 at 4:09 pm By Chris Ng Filed Under Cars, Malaysian Makes, Proton, Proton Preve The name of Proton’s P3-21A was officially confirmed yesterday, and the date of its arrival has also been mentioned – the Prevé is set to be launched by Prime Minister Datuk Seri Najib Tun Razak on April 16. I was coming home from a snowboarding trip when all of a sudden the engine light comes on and I felt a strange vibration whenever I stepped on the gas. It isn’t as smooth as it was before. Then the issues with a rough idle and bogging down/jerking while accelerating happened. N/A: Faulty spark plug. You are driving smoothly down the highway; next thing you know the engine starts to buck and shake. The 98 US WSM lists the following possible causes for "Idle speed too low and excessive engine shake":. Typical problems include hard starting, rough running, a need to adjust the carburetor during use to keep the engine from stalling, a need to rev the engine to ke. In all three areas, it would have a negative effect on the way the engine runs, especially when the engine is idling. It runs great and i’ve been enjoying it tons. Engine Hesitation Problem: Car Hesitates When Accelerating ARP September 16, 2017 Engine Related Issues Leave a comment Hesitation is when the engine stumbles, misfire or when you step on the throttle or you accelerate it lacks of power. help please, Kohler 27 hp losing power and running rough. Another strange thing caught my interest. When I got it to run it seemed to run okay at wot but when I throttled down it seemed to be missing and running rough. The idle of a car engine is kind of like a human heartbeat: You can tell what shape it's in just by listening. At the end of the drive I ran the car's internal "Key On Engine Running" self test which didn't show any errors. Nissan — Engine Runs Rough or Bucks, No Power Owners of 2002-03 Nissan Altima and Sentra models may come into your shop with a complaint that their engine runs rough. A car running rough can be tricky to diagnose. Its a 1999 X1 Lightning with 4092 miles on it. When staring with a cold engine it runs fine but, as soon as the engine warms up to operating temp (only a couple of minits) it will hesitate/stumble around 1200 to. Cranked it up and got two blocks, then when I tried to accelerate it stalled. Your engine needs air, spark, and fuel to run, and the air part of that equation can be compromised quite a bit if the air filter is clogged and dirty. when going down road, car runs ok as long as i dont mash the gas or need to accelerate fast. 5's, and a. Also very hard to start because of periodic 'backfire' while cranking that brings engine to standstill. This will cause your overall driving experience to feel rough and you'll likely be bouncing a little bit in your seat from it. If the accessory drive system is the root that car makes rattling noise when accelerating , you can remove the belt and spin each of the pulleys to see if anyone wobbles or feels loose. At idle it sputters and sounds more like a little boat engine to me. rough idle/stumble on acceleration(low RPM's) Ok, when I purchased the bike it ran smooth. Engine runs rough or misfires / running on less than all four cylinders; Engine runs smooth when cold, then idles rough or stalls when warmed up. It will literally smother the engine, hurting fuel economy and acceleration. But between about 80 km/hr and 100 km/hr while reving at about 3000 rpm there is some roughness. And when the engine runs rich, it’s exact the opposite: too much fuel in the combustion chamber and black smoke comes out of the rear exhaust. A misfire will cause the engine to momentarily stumble, or lose rpms, and then regain its normal engine speed. I was able to duplicate the problem and it persists. This can lead to the engine running too rich or too lean (check your sparks for evidence). The best course of action is to take your vehicle to an Omaha auto service professional, but here are a few things it could be…. Well today the engine light turned off again and the car feels like its running normal again. i havent ran into any power issues after cleaning everything. 3 Van was running great then while driving down the road it was as if someone flipped a switch. Also, when I say the engine runs rough, it isn't the same as miss-firing. This causes it to stick open, causing a rough idle or engine stall. I gave it full throttle in neutral (standard) and it reved to about 4500 then bogged down to about 1500 spitting and sputtering with the pedal all the way down. I went thru drive thru car wash and drove in rain, and seems to run better. The bike sputters on acceleration and runs rough under load. And if you aren’t using it, use non-oxy fuel. When its cold, its runs a bit rough, and a mild shake. If a valve spring has broken or a cam lobe has worn down, it will cause the engine to misfire and run rough due to the loss of compression. I took it to the parts store & had them read the code. A smoothly running engine is often taken for granted until a problem comes to light and the operator is left to diagnose the problem. Here are some: Stalls at idle, stalls when I put the clutch in, stalls when I turn a corner, misfires, surges, no power, cuts out, no power at top revs, runs rough, etc. I can't tell if it's tied to the transmission or not, but I figured I would ask the community, since you guys know more about the AWD driveline than I do. 2004 yamaha 115 four stroke. Why does my engine spit or backfire? First off, you need to determine whether it is backfiring out the exhaust or back up through the carb. About 10 miles later the check engine light came back on and it started to slightly run worse. Let me use an idle complaint that had me on the ropes as an example. Just an information post for everyone with the vortec 5.