Get this INSTANT DOWNLOAD 2000 Polaris Personal watercraft Virage TX, SLX, Pro 1200, Genesis & Genesis FFI repair manual delivered straight to your computer in seconds and fix your problem now. The reason of this problem may be that the spark plug fails to produce the spark. Now it misfires and shakes every time I start it. Spark plugs use the electrical current received from ignition coils to ignite the air/fuel mixture within the combustion chamber. It just idles kind of rough - moreso than I think it should. Checked to make sure everything was clipped back in on the packs. This means 18 mpg went down to 13 mpg on highway driving. With a high performance ignition coil spark plug gaps can be increased. It seems to run fine, gas milage is the same. 5T Vibration/rough at idle only. Pull the spark plug wire off the spark plug. Rough idle issue and low RPM rough I have owned this bike since 100k KM. chevy forum at Car Dealer Forums; I have an '86 GMC 1/2 ton pick-up that now has a 5. It's not hard to start, but the idle is pretty rough for a minute, until it warms up. Sooty spark plugs and fouling. haven't changed the spark plugs since I bought it with 21,000 miles. I changed the spark plugs, plug wires and coil pack. I made sure to do each plug one at a time so that I didn't get the wiring mixed up. I got my valve cover gasket installed today and changed out my spark plugs. I also got a Onboard diagnostic self test not complete on the computer. Still freaking sitting at 800 or at 300rpms at idle. What could cause a 2004 ford F-150 to idle rough when coming to a stop and the check engine light came on?. it had a rough idle (only) so i went and got new plugs (ngk) and plug leads (topgun) changed them over 3 at a time (could be the reason) why when putting the foot down. But now there is a rough idle, and when I first start going it is really sluggish accelerating (it seems to get better once I've been going for a minute or so). OEM Quality Materials. Components in the fuel, ignition, emission and other systems should work correctly. If any of the spark plugs are misfiring or are not producing enough of a spark to ignite the fuel, then not only will the engine idle. Keep working the speed down and keep the idle needle screw adjusted until you reach the desired idle speed. I went through all the fluids, plugs, ignition system. They are not suppose to wear down. To check the spark plugs, simply remove one spark plug at a time and place it on the ground somewhere away from the engine's belts and away from the spark plug hole. It is also necessary to clean the MAF if you're running aftermarket oiled air filters like K&N, BMC, etc. These engines are fitted with Platinum or Iridium tipped spark plugs meaning that replacement is due only after 150,000km and equivalent replacements only should be used (there is a bunch of genuine and non-genuine BA-BF Spark Plugs and Coils available on Ebay). can some kind souls share his expierence w. Helpful information and resources on Ford 8N, 9N, 2N, NAA tractors from SSB Tractor, a leading provider of tractor parts, manuals, implements and toys. Now the engine seems to idle rough. 8 Denso Iridium SK20R11. Only thing that i noticed since day 1, is that the car runs rough, the engine shakes at idle more that it ever did before the spark plug change. So I figured i just need a tune up so I went and bought new plugs and wires and replaced the old ones. 2005 colorado 3. I decided to change my own spark plugs today at 120k miles as preventative maintenance. It seemed to start fine, however my wife was telling me today that the car shakes when in gear at idle now. Sometimes, an inexpensive fuel cleaner can clean clogged fuel lines. Be careful not to drop any foreign matter into the wells. It seems to run fine, gas milage is the same. Gapped correctly. Im still investigating the cause of my idle problem, and will check the vacuum hoses and throttle body at the weekend to see if there is an underlying problem thats throwing the default idle position off slightly. How to Troubleshoot a Poulan Chain Saw That Won't Start Replace the spark plug and try to start the chain saw. I have a 2009 dodge Dakota with a P050D code for my check engine light. now it runs perfect. Have you changed the plugs/wires yet?. 2004 Mazda MPV Spark Plug Diagram Changed Coil Packs And Plugs On Cylinder 3 6 Still Getting | 2016 Car 490 x 632 · 6 kB · gif Source Location of Ignition Coil On a Lt1 help finding causes for random multiple cylinder misfire on my 96 FWB 792 x 612 · 93 kB · jpeg Source. and did not change the idle rpm's. 8L (351 w) for months now, and I set out to "shotgun" the sumbitch until I found/fixed it. Otherwise, check the coils (a. I've got it parked out in front of my garage. I find both hard to believe since the spark plugs are brand new (OEM-spec Champion Platinum plugs) which I've always used and I can't see the ignition coil(s) going bad suddenly. Standard copper spark plugs last up to 30k miles while iridium and platinum spark plugs can last over 60,000 miles. I'll share with you Misfire testing and troubleshooting techniques. ) Spark at spark plug, but no start. How to Troubleshoot a Poulan Chain Saw That Won't Start Replace the spark plug and try to start the chain saw. Now it misfires and shakes every time I start it. Like the air filter, the spark plug is extremely important to a functioning lawn mower, yet inexpensive and easy to replace. 95% of the driving is short runs around town in a hot environment. The Ignition Specialist full-line product offering includes: spark plugs, glow plugs, ignition coils, coil-on-plug boots and wire sets. Harley-Davidson Fuel Injection basics It is a sad day in Hogville. 1996-98 MFI engines uses AC-41-932 plugs, gaped at. A: If this is the first time you’ve fouled a set of plugs, I’d change to projected tip spark plugs of the same heat range and try again. Take all the plugs out and keep them in order to identify the cylinder. Replace any that are fouled or burned. Fuel and air comes from the fuel system and carburetors. So i changed the ecu and coded it. There is one hose by the EGR valve that is known to easily popup and cause rough idle. There are lots of ways to put the cams back in, most of them wrong. I changed my spark plugs from NGK zfr5f-11 to Champion 318cc (RC12MC4) and before I got the wrong size they did not fit but some how it got stuck in their spark plug hole. They are Champion plugs. Harley-Davidson Fuel Injection basics It is a sad day in Hogville. Ive been driving for over 200miles now and service light still reads coils in 1 and 2. Why? - Answered by a verified Toyota Mechanic. Seems to be running fine otherwise. Checked the plugs ( J12Y's are in there now, don't know what modern plug is suitable, have only 2 AC 46's ), they're clean and @. Thank you!. I replaced the pressure regulator, 02 sensor along with a new exhaust, new cap and rotor, fresh oil change, new spark plug wires, and I changed my spark plugs last Spring. Still freaking sitting at 800 or at 300rpms at idle. What is weird is that the truck idles good in drive, but in park it sounds terrible. Tuning your Harley Davidson carburetor is simpler than most think and can be performed with a few common tools. Iridium Toyota Spark Plugs. ) Spark at spark plug, but no start. Your engine could be idling roughly due to a number of different reasons. If your spark plugs are fairly new and fuel filter as well, the O2 sensor is another wear part that it won't hurt to change, if you are on the original, it's due. A: If this is the first time you’ve fouled a set of plugs, I’d change to projected tip spark plugs of the same heat range and try again. As I had only changed the plugs this obviously had to be related to plug change. I got my valve cover gasket installed today and changed out my spark plugs. On the change out of my 97 E320 104 I-6 spark plugs, I didn't see any info on what the gaps need to be for the 104 I-6 engine spark plugs? May 18, 2014 : Followup from the Pelican Staff: If it is a platinum or dual-electrode plug, there is no gap to adjust. This is my first crv but nothing out of the ordinary happened during the process. This will possibly smooth a rough idle and will increase fuel economy. to much air we changed all the sensors in the throttle body as well ass rotor button and distributer spark plugs and wire can't figure it out: histnut1066 Dodge Dakota JOIN HERE 8/27/2015 10:45:33: RE: rough idle IP. With timing light it appears that the misfire is in the back three. With 84k, I pulled the factory Iridium plug out and found it worn down quite a bit. 12/17 This is an old. I changed the filters one night, ran just fine. Before the switch to new spark plugs (NGK Laser Platinum Spark Plug BKR6EQUP), the car trembled at idle and when driving beyond 60mph. I have just put in brand new Volvo spark plugs. Typically, a vehicle's spark plug will need to be changed about every 30,000 to 40,000 miles. it had a rough idle (only) so i went and got new plugs (ngk) and plug leads (topgun) changed them over 3 at a time (could be the reason) why when putting the foot down. 7l, I changed the spark plugs with the NGK from Toyota at 60,000mls. So I swap plugs and notice the PCV is cracked. If any of the spark plugs are misfiring or are not producing enough of a spark to ignite the fuel, then not only will the engine idle. Runs okay for a short period and then starts to misfire. I researched it online and the consensus was a bad coils. Toyota and Lexus rough idle after battery replacement A common concern DIY Toyota and Lexus owners call CARspec for is a rough idle, starting and dying, or a hard start just after replacing or disconnecting the 12 volt starting battery. I find both hard to believe since the spark plugs are brand new (OEM-spec Champion Platinum plugs) which I've always used and I can't see the ignition coil(s) going bad suddenly. Now when I drive it, it seems like I am misfiring on one of the valves. Spark plugs don’t last forever. I changed my spark plugs from NGK zfr5f-11 to Champion 318cc (RC12MC4) and before I got the wrong size they did not fit but some how it got stuck in their spark plug hole. MERCEDES S500 SPARK PLUG CHANGE MISFIRE , ENGINE LIGHT , ROUGH IDLE This feature is not. The spark ignites the air and fuel mixture. 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. When I pressed the gas it began to run rough again. Old or faulty spark plugs could be the culprit! After all, these small spark plugs have a big job to do. But now there is a rough idle, and when I first start going it is really sluggish accelerating (it seems to get better once I've been going for a minute or so). But the cutaway diagram of the Champion spark plug now on the website shows the new fired-in resistor. Fuel and air comes from the fuel system and carburetors. CDI Electronics has the spark plug wires available as a set P/N: 931-4921. Issue 4 – Loose gas cap. MERCEDES S500 SPARK PLUG CHANGE MISFIRE , ENGINE LIGHT , ROUGH IDLE This feature is not. How to Troubleshoot a Poulan Chain Saw That Won't Start Replace the spark plug and try to start the chain saw. Be sure that this is what you have and the gap is correct. I'm talkin' a 1" spark though air between the boot and a ground. with rough idle and loud. Ran ok, old points, new plugs, new wires, new rotor, new cap. Car has a rough idle. it was running fine before, no CEL. Drove a mile and on idle it ran really rough and the exhaust was "puttering". Changed fuel filter, oil, gear oil. The wires are all connected correctly and the plugs are in tight, with the proper gap. Since the spark plug resides in the combustion chamber, it is a window into the engine. You may have a misfire, a vacuum leak, or a clogged/faulty idle air control valve. What gives? Where do I turn now? Well, my beloved VW folks, I have been given the arduous and somewhat scientific task of explaining the causes of sooty spark plugs and what to do about them. Im still investigating the cause of my idle problem, and will check the vacuum hoses and throttle body at the weekend to see if there is an underlying problem thats throwing the default idle position off slightly. All these components were found to be serviceable. As said earlier if it is operating temp related it isn't spark plugs, so maybe you should put three spark plugs into it. If your Mercedes-Benz has over 80,000 miles and still has the original spark plugs, it makes sense to change the spark plugs before you pour money on any other repair. Sounds like spark plugs or your coil-on-plugs. DIAGNOSE – ENGINE IDLES TOO HIGH. How do we adjust an engine’s idle speed? In the past, adjusting an engine’s idle speed was easy. ESP/BAS ETC Light Sorry for the long post but I though it might spark some Ideas to get this problem we are all having resolved. There's one thing that I'll note about Mk7's which is that they seem to eat spark plugs pretty quick, especially when tuned. Your 2006 model has shorter spark plug life than the 2008 and. Most auto manufacturers suggest having new spark plugs installed about every 30,000 miles; however, spark plug longevity depends on the condition and type of spark plug. Changed plugs now Rough idle and loses power. So read this article for tips and tricks on how to differentiate spark plug problems from other issues. I changed the spark plugs, plug wires and coil pack. All Opti-Spark distributors use an encapsulated plastic distributor cap to protect the conductive ink that transfers the high-voltage to the spark plug wires from the rotor. I'm going to change the plugs tomorrow, but my question is really if this could be the start of my head gasket failing? It will rough idle while stopped, but be fine in neutral or park. i seriously had doubt in it. Re: Update: '07 With The Rough Idle Heh - never mind, I see a lot of other people already responded I think it was in one of the other posts where platinum or expensive spark plugs cause the symptoms you are describing. If I drive it fast it idles much higher, such that if I take my foot off the brake (automatic) it will reach about 40 or 45mph without touching the accelerator. I had the same issues after recently changing my spark plugs on a 2008 Acadia. Though it is an improvement because, before the change, air temp didn't seem to affect the idle. i just decided to change my plugs due to high mileage. I changed the filters one night, ran just fine. Learning how to change spark plugs is a rite of passage among gearheads, and it's not as daunting as it sounds. And you still have spark at each spark plug now? If you are reading 12-13 PSI at the fuel rail under the hood, that is too low and I can only suspect you have a fuel pump issue or a problem inside the fuel tank. Check all the plugs for the same symptoms. Bad spark plugs can indeed cause an engine to idle rough. The owners manual it says gap should be 1. Please try again later. Plug and play! All clips included and it lined up as original, you can’t install it on or in wrong order with these. Re: who all has rough idle in a 3. I also noticed that there is a loud sound like a large vacuum leak near the back driver side of my engine. Cylinder 4 made no change in engine idle. One thing to keep in mind is that rough idling is not the problem - it is a symptom to an engine issue that has yet to be diagnosed. Problem: My engine was idling too fast so I closed down on the idle mixture screw to reduce the speed but it runs rough. All Opti-Spark distributors use an encapsulated plastic distributor cap to protect the conductive ink that transfers the high-voltage to the spark plug wires from the rotor. Changed spark plugs and cleaned throttle body, car idling weird. Spark plugs that are improperly installed can also cause high or surging idle. Having spark plugs foul out with dry sooty deposits is a direct result of excessive fuel. The only thing that was different was adding anti-seize to the threads. This will possibly smooth a rough idle and will increase fuel economy. I figured it is time to replace the spark plugs. When the engine is started cold, regardless of the outside temperature, the idle is rough and there is a noticable power loss. With the light off now the learning curve is complete. To read a spark plug and assess engine troubles, you first have to remove it. After checking the codes, the engine stopped misfiring, but was still running rough. I'm not 100% sure what plugs are in there. Yeah, tried that. Rough idle after I changed my plugs 2 Answers. Today I decided to change my spark plugs, I figured I have had this car for 2 years, I think its about time. Hard Cold Start/Rough Idle then Smooths Out?? maintenance & nonperformance. My '02 trailblazer with 92,000 miles has been idleing rough and vibrating and I changed out the spark plugs. Toyota and Lexus rough idle after battery replacement A common concern DIY Toyota and Lexus owners call CARspec for is a rough idle, starting and dying, or a hard start just after replacing or disconnecting the 12 volt starting battery. How come my car won't idle after i changed spark plugs? 6. And to my surprise…still a noisy shakey rough erratic start and idle. Oil change fuel pump and filter in tank change spark plug change wires and coils. A: If this is the first time you’ve fouled a set of plugs, I’d change to projected tip spark plugs of the same heat range and try again. Make sure you did not pop a hose out of place. Troubleshooting tips: Power pack Johnson outboard, power pack vs. Soon the Check Engine light came on, so I turned the car off. Been fighting with the infamous "rough idle" situation on my 1996 F-150 w/ 5. When spark plugs become faulty, they cause your engine to run rougher than usual, which results in symptoms such as a rough idle. I cannot feel a misfire, but I can feel the rough idle. I told her to run it for a few days and let me know if it does any more stumbling/jerking. Anyway, seemsit has developed and intermittent rough idle over the last two weeks since I have been out of town on bussiness. Disconnected the Check Engine Light and turned back on today after I floored it and seemed like their was a misfire. Been fighting with the infamous "rough idle" situation on my 1996 F-150 w/ 5. now i dont let my get as bad as some people do. I would be turning out of parking space and my car would studer and not go. and the O-rings surrounding the spark plug wells. The Iridium spark plugs are made to last at least 100,000 miles. Going to replace my CPS with a Mopar unit per your experience. Now the truck does not want to idle. Replacement is £31 and just the two screws hold it on. This is extremely apparent when I drive up hills slowely. it splatters and then takes off like a sling shot. Inspect the spark plug for signs of wear or damage. Recently put a whole can of carb cleaner through my throttle intake. This is usually caused by two things: Improper fuel level and/or blown power valves. It is also necessary to clean the MAF if you're running aftermarket oiled air filters like K&N, BMC, etc. Hey Guys, I changed my spark plugs last night as preventative maintenance and torqued them to 18ftlbs. I replaced the spark plugs, CPS, pre-cat O2 sensors, and new MAF, but nothing has fixed it so far. I have run fuel system cleaner several times recently and even tried premium fuel and it is still running rough and shaking at idle after I come to a stop. Re: Update: '07 With The Rough Idle Heh - never mind, I see a lot of other people already responded I think it was in one of the other posts where platinum or expensive spark plugs cause the symptoms you are describing. etec 90 hp suddenly running rough/stalling. A bad spark plug will give the common problem referred to as engine misfiring; some spark plugs are not firing as expected. But now there is a rough idle, and when I first start going it is really sluggish accelerating (it seems to get better once I've been going for a minute or so). The problem started after I changed the plugs. I have a 2000 Ford Expedition 5. 2005 colorado 3. then start shaking again. Possible cylinder head or valve damage on the GM 2. Spark plugs are used to ignite the fuel through the use of a spark. Your engine idles when it is a stationary and in this position the engine normally produces around 1000rpm. first sign of a rough idle or bogging down they get changed. When pulling a full rated load (9600 lbs) at highway speeds the truck shudders slightly as though it. During the trouble shooting process, which I had to do myself while the dealer did nothing during warranty period, I first changed spark plugs. Comments: I had bad idle with service engine soon light , changed all plugs and coils the car was perfect now. spec stage 3, custom intake, bbm fuel rail, billy boat 3in exhaust,ecs bleeder block,mbc,fmic,bfi mounts,cm flywheel,front mount interccoler, aeb head cat 3652 cams, scat rods je pistons super tech valves and springs. Cylinder 4 made no change in engine idle. nothing different, same synthetic oil I have always used (and suggested by the dealer). A common cause of an engine running rough is faulty ignition timing. I'm POSITIVE everything is installed correctly and all plugs/coil packs are on tight. 58 and 20 seconds the ignition process starts at 10 degrees BTDC. What causes a rough idle? A rough idle can be caused by many different car faults. I changed the plugs and oil yesterday. If your spark plugs are fairly new and fuel filter as well, the O2 sensor is another wear part that it won't hurt to change, if you are on the original, it's due. Metal parts should be lightly coated with oil to protect them from rust and corrosion. As said earlier if it is operating temp related it isn't spark plugs, so maybe you should put three spark plugs into it. Problem with Lawn Mower Engine Running Rough My lawn mower was running rough, so I changed the spark plug. But now there is a rough idle, and when I first start going it is really sluggish accelerating (it seems to get better once I've been going for a minute or so). I'm not 100% sure what plugs are in there. Seems to be running fine otherwise. when i changed the spark plugs it started doing the same thing. I can feel the truck shake a bit feeling rough while idling at a stop light. Did nothing to the car. Spark plugs overly clean …with no deposits or slight glazed appearance ; Rough, erratic idle that drifts toward higher rpms than expected based on the setting of the curb idle screw. Please try again later. I changed the OEM Bosch spark plugs that had 60,000 miles on them with Bosch Platinum +4 (Part# 4417) plugs. Typically, a vehicle's spark plug will need to be changed about every 30,000 to 40,000 miles. It's not hard to start, but the idle is pretty rough for a minute, until it warms up. It started easily and ran fine; but the next time I used the mower, it was hard to start and ran poorly again. Now when I drive it, it seems like I am misfiring on one of the valves. Spark plugs don't last forever. For the rest of the day it will run completely normal. Now the truck does not want to idle. A distributor cap regulates the firing order of your vehicle's engine. Since it was running rough me and my father decided to turn that black knob on the Idle Air Control Valve to see if it make it any better, but it got worse. ) Replaced the plugs, intake cover gaskets, cleaned the component that snaps onto the plugs since the two rear spark plugs were soaked in oil and have gone back over everything again to make sure everything is connected. This means that it fires 2 plugs every time it fires a plug. Dealers are notorious for starting cars, moving them fifty feet, and shutting the engine off. Symptoms to know when spark plug needs to change 7. 2005 colorado 3. Having a a major dilema with a rough idle / Multiple Cylinder Misfire on my 2001 Chevy S10. Decided to change the spark plugs as preventative maintenance. So i changed the ecu and coded it. It seems to run fine, gas milage is the same. 05 v6 - low idle after spark plug change After having the dealer replace the plugs on my 05 v6 4runner, my idle speed after warm-up is down to 500. These are just a few items that could cause a rough idle. The engine can't start even after several attempts. the winch really drains the battery and i can only start it so many times till the battery runs down [ with the. My 85 has a rough idle. I was out of town when my original spark plug wires got a burnt so I had to put other wires on and it ran really rough, got to my town and got new wires from harley, now it starts for one second and dies, checked plugs and cleaned them, took air cleaner off and sprayed with wd40, it is getting gas, but only staying alive for a second. Was getting engine trouble light with P0171 and P0174 codes. , what i found that ecu give them an electric pulse and after 10 sec. Plugs containing the suffix TS or CTS can be used interchangeably. They are Champion plugs. Most of the time though, clogged fuel injectors create a rough idle and lack of power condition due to the lean Air/Fuel Mixtures they create in the cylinders. They can answer questions for any Yamaha outboard model or horsepower. A worn out or faulty spark plug is likely to add on to the car vibration when idle. Re: Honda 130 hp rough idle We removed the spark plugs after the engine was idling and the # 3 plug is wet - apparently not firing. I've had my '13 ST3 for about a month now. I cannot feel a misfire, but I can feel the rough idle. So remove the seat, the front spark plug covers, and decide how you’re going to handle the gas tank. I changed my spark plugs and wires now my car has a rough idle and seems to be backfiring. The other quart was all over my engine. Your engine could be idling roughly due to a number of different reasons. ) Spark Plug wires E. didn't change anything. The spark plugs are showing that it is. Thank you!. Car has a rough idle. Helpful information and resources on Ford 8N, 9N, 2N, NAA tractors from SSB Tractor, a leading provider of tractor parts, manuals, implements and toys. Some of the most common problems reported by PT Cruiser owners are PT Cruiser idle problems—rough or bogged down idling—when the PT Cruiser comes to a complete stop or when the air condition is. The symptoms of faulty spark plugs are pretty general and can be attributed to a number of other issues. All the lines are hooked back up so no vacuum leak that I can tell. Having spark plugs foul out with dry sooty deposits is a direct result of excessive fuel. It seems to run fine, gas milage is the same. You'll need a cold engine, a T-30 Torx bit, a socket wrench with an extension, a torque wrench, a special 12-point spark plug socket and some anti-seize. Disconnected the Check Engine Light and turned back on today after I floored it and seemed like their was a misfire. If truck was running. Recently put a whole can of carb cleaner through my throttle intake. Ran ok, old points, new plugs, new wires, new rotor, new cap. Now the truck does not want to idle. My front carb spark plugs look a nice grey/brown colour. Seems to be running fine otherwise. I picked up 8 new plugs, pulled the plug cables, and then replaced them all, one at a time to ensure they are all in the original locations. so i changed the sensor and connecter. Typically, a vehicle's spark plug will need to be changed about every 30,000 to 40,000 miles. The idle is better when the air temps warm up but still rough under about 40degF. I've got it parked out in front of my garage. ignition module, Evinrude power pack, Evinrude power pack problems, Evinrude power pack troubleshooting, Evinrude power pack problems, Evinrude power pack testing, Evinrude power pack symptoms, Johnson power pack symptoms, Johnson power pack testing. I'm not 100% sure what plugs are in there. Start the car and it idles poorly, revs, but then idles with a shake and a low idle. Hard Cold Start/Rough Idle then Smooths Out?? maintenance & nonperformance. Solution: Never attempt to control idle speed with the idle mixture. The symptoms of faulty spark plugs are pretty general and can be attributed to a number of other issues. Spark plugs don't last forever. Also clean. We recommend that when the spark plugs are replaced, to use the same type of spark plugs that the vehicle was originally equipped with. Replacing tired plugs with a set of new plugs will smooth out your. Then I’d do a spark test on each cylinder. Comments: I had bad idle with service engine soon light , changed all plugs and coils the car was perfect now. Dealers are notorious for starting cars, moving them fifty feet, and shutting the engine off. The idle of a car engine is kind of like a human heartbeat: You can tell what shape it's in just by listening. Ignition systems, including spark plugs, plug wires, ignition coils, and ignition timing are major players, as are lean air/fuel mixtures and mechanical issues within your engine. Causes include worn, fouled or damaged spark plugs, bad plug wires or even a cracked distributor cap. It started easily and ran fine; but the next time I used the mower, it was hard to start and ran poorly again. Engine Running Rough / Misfiring: If you’re having a problem with your V10 running rough / missing, it may be your Coil On Plugs (COP). It may be worth looking into. After a few minutes with my foot on the gas so it doesn't stall, the car returns to normal idle and smooths out. You should also check that the spark plug gap is set properly. If the mechanic changed the coil then he should have changed the spark plugs and wires because, often as not, a faulty plug will kill the wire which will in turn kill the coil if the problem goes on long enough. Well after the spark plug change and coil swap the misfire on cylinder 5 is still there, so I know it was not the spark plug or the coil pack. Cylinder 4 made no change in engine idle.