Changed Spark Plugs Now Idles Rough
6L used in trucks, vans, and cars. I checked with my scanner and got misfire in the banks 1 and 3, I cleared them and turned the car again. The wires are all connected correctly and the plugs are in tight, with the proper gap. i tried 2 different brands of copper -- champion and bosch, WTF! i just changed spark plugs and now it idles really rough - JeepForum. I've have read through a few posts on the forum here, and I still don't know where I should begin here. I have video as well if you would like to see. ) Coil weak or intermittent - you should see 3/8" fat blue spark with a good coil 3. The ceramic should be a light tan and the electrode will show some signs of wear, but nothing should be coating the spark plug. They are cheap on the falcon though <40 bucks each for geniune, and normally replace them when you replace the plugs (as they are painful to remove in 1 piece). It does not matter whether is cold or warm start. The plugs i used are SP515 ( MC brand from Ford Dealer ). it now has 130,000. Once the car is moving it is normal. 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 put a bottle in every time a use a total of 70 gallons. Here are the current symptoms that started as of three weeks ago: rough idle, while idling the CEL will flash, the code reader device says its a misfire, and each time checked and cleared its in a different cylinder. One reason for a rough idle is it could be time to clean out the fuel injectors or it could be time to change out the spark plugs. 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. It seemed to start fine, however my wife was telling me today that the car shakes when in gear at idle now. I changed the OEM Bosch spark plugs that had 60,000 miles on them with Bosch Platinum +4 (Part# 4417) plugs. Then I changed the spark plugs last night, and now it has a low idle in gear, reverse or forward. If you are getting a code 34 you should look for a collapsed or blocked vacuum line going to the MAP sensor or electrical problem between the ECM and sensor. when i changed the spark plugs it started doing the same thing. After removing the spark plug i noticed there was some oil on the first few threads of the spark plug. You should see a spark. I changed my spark plugs this weekend. Its a V6 4. 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. Rough idle and cutting out at a steady rpm, found out the vac advance was bad replaced it, still ran bad. Remove each spark plug, ground the threaded base against the engine block and, with the spark plug wire connected to *only that plug*, have a friend crank the engine. Before the plug change my Jeep would idle really low, like 500rpm's and it has stalled a handful of times at lights. Soon the Check Engine light came on, so I turned the car off. Because higher firing voltages are required to bridge excessively wide spark plug gaps, it’s not unusual to discover a damaged ignition coil or a perforation in a spark plug wire. Spark Plugs. My 99 STS recently starting having a rough idle and sluggish acceleration. Rough run. I made sure to do each plug one at a time so that I didn't get the wiring mixed up. My '02 trailblazer with 92,000 miles has been idleing rough and vibrating and I changed out the spark plugs. I made sure firing order was correct and is still running rough. mines developed a bit of a rough idle and a little slugish to, but mine is the opposite, it will start and lope like a lumpy v8 at 400rpm for about 4 seconds then get up to revs, tried the spark plugs not long ago. 2005 colorado 3. I know ill have to replace the O-rings. Cleaned egr, changed idle air sensor, checked fuel pressure regulator by removing. i tried 2 different brands of copper -- champion and bosch, WTF! i just changed spark plugs and now it idles really rough - JeepForum. What is a "dual coil" glow plug? Dual Coil Glow plugs, as their name implies, have two heating elements instead of just one. Boost seems to be on and off, and when it doesn't work, I get. How to fix a rough idle/clean, Customer Replaced Spark Plugs And Now It Runs Bad!? - Duration: 9:21. While these cars typically maintain good drivability otherwise, the rough idle seems to be traced back to spark plugs. 7l, I changed the spark plugs with the NGK from Toyota at 60,000mls. Daihatsu - most models Surging, cutting out & runs rough. As I had only changed the plugs this obviously had to be related to plug change. So far as I have been able to tell, they didn’t even issue a press release. 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. by Kyle McFadden. We changed the coil and wire because we had a spare coil. Replace coil pack. Faulty spark plugs may cause rapid discharge of the battery, so this spark plug need to be replaced. Small Engine Troubleshooting. If the scooter starts, it must be getting some sort of spark, but the spark may be weak or there may be a problem with the ignition timing. I have a '97 PSD and it idles a little rough when warmed up. Vehicle would misfire, when engine was under load. Rough idle and cutting out at a steady rpm, found out the vac advance was bad replaced it, still ran bad. Was a problem found? — Go to Step 24. Next was the TSB for rerouting plug wires, no change. Over or under can cause problems. These are stick coils and they are an absolute bear to get at. They are not suppose to wear down. This article applies to the Acura TSX (2004-2014). I believe they were the factory plugs at 98,000 miles! 4) I also changed oil but that can't be related to my problem. Solution: Never attempt to control idle speed with the idle mixture. i seriously had doubt in it. Changed fuel filter, oil, gear oil. Rough Idle Was Always Present and What I Replaced did Not Solve the Issue. What Tests Can I Perform to Find the Cause of the Misfire Condition?. Make sure you did not pop a hose out of place. Once you take an old spark plug off, take a new one and smear some anti-seize compound on the threads. So i went to change my spark plugs the other day and after everything was installed back together i had a rough idle?? So i took the new plugs out to make sure it wasn't those and re-installed the original plugs, still rough idle. Engine has a rough idle. Upon removal, plugs should be examined for evidence of the engine conditions described above. That's because a misfiring engine can be caused by many mechanical problems. Remove the spark plugs with a spark plug puller. 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. Everything has been running fine on my TB, I bought it with 62k on it, 77k now, figured I should change the spark plugs since who knows when they were changed last. Because higher firing voltages are required to bridge excessively wide spark plug gaps, it’s not unusual to discover a damaged ignition coil or a perforation in a spark plug wire. Since you have the 1. Some vehicles may not use spark plug wires, if there is a coil on the plug. Like when I put the parking brake on, the rpms spike for a few seconds up about 500rpms. I then proceded to drive the car around town on errand for approx 80 miles before I caught it. A faulty spark plug wire can cause an engine misfire, which will trigger the light and cost you a trip to the repair shop to turn it off. Ignition and Spark. Also does not idle at a consistent speed and occasionally idles rough. 5T Vibration/rough at idle only. 7L Mustang is 1-2-3 on the passenger side and 4-5-6 on the drivers side. I wouldnt pull the spark plugs out unless the cel or engine gives you problems or fuel mpg goes down. Changing Plugs, Wires, Cap And Rotor on a GMC Torque directly affects the spark plugs' ability to transfer heat out of the combustion chamber. I pulled the motor and checked over everything and played with the timing change discussed here, but didnt test it out on the car running. Problem with Lawn Mower Engine Running Rough My lawn mower was running rough, so I changed the spark plug. Start the engine and see the color of the spark. They regapped the plugs and all is well, plugs basically had no gap. How To Diagnose Ford Misfire Issues Using Mode $06. I wonder too about spark plug wires as posted below, and wish to caution anyone doing their own plugs to know that spark plug wires need to be handled with care, no extreme bending or pulling on the wire to get it off the plug etc. 1996-98 MFI engines uses AC-41-932 plugs, gaped at. On a cold start it even sounds like there may be some tapping from the timing cover. I'm POSITIVE everything is installed correctly and all plugs/coil packs are on tight. 00 part that is replaced by removing two screws. HowTo: Sea Doo Running Rough? Change the Spark Plugs First 28 This entry was posted in DIY Reference Sea Doo and tagged DCPR8E dielectric engine running rough losing power replace replace spark plugs RXP Sea Doo spark plug on July 10, 2013 by Steve Jenkins (updated 1574 days ago). It does not matter whether is cold or warm start. OEM Quality Materials. Spark Plugs Replacement on a 3rd Gen Prius. The gaps on the old plugs were pretty big (>0. It is intended to help you map out a troubleshooting plan. In researching the archieves, I found a number of threads where Arthur Dalton provided insight to the things that can cause a rough idle. A trained mechanic can reset your idle speed setting easily. My check engine light is on — now what?. I believe they were the factory plugs at 98,000 miles! 4) I also changed oil but that can't be related to my problem. The raised design offers a strong spark, smoother idle, and maximizes performance. I was wondering if anyone else has had this problem. I Idle around 500 most of the time and lately the idle has been up to 850 rpm at a intersections. Now I am getting a slight missfire at idle every few seconds. now it runs perfect. Also broke the egr valve in the process, replaced. Learning how to change spark plugs is a rite of passage among gearheads, and it's not as daunting as it sounds. I changed the spark plug on my old mower without problem, but now I have a mower I bought last summer and it has a very long snug boot that I can’t get off my spark plug. If resistance was low, the plug would get very hot quickly, but would burn out. To determine if the spark plug is defective, use a spark plug tester. Bad spark plugs can indeed cause an engine to idle rough. Now the engine seems to idle rough. (6) Adjust your driving habits. I just changed the spark plugs from NGK platinum 5 heat range gapped at about 0. Your engine idles when it is a stationary and in this position the engine normally produces around 1000rpm. Step 3 - Once you are done, replace the grommet and take a good long run on the bike. I changed the spark plugs, the air filter, the pcv valve and it still runs/idles rough. I have video as well if you would like to see. Rough idle after I changed my plugs 2 Answers. I found a very good explanation, on allpar, as to why our Hemi engines have 16 spark plugs. (Needed warm weather, brother-in-law and room in the garage. Remove the spark plugs one at a time and check to see if they’re clean and properly gapped. I put a bottle in every time a use a total of 70 gallons. Engine light is on and the traction control service message is on and engine runs rough after I changed wires and spark plugs today. Hello, I have a 1996 King quad 300 4x4, it would not start at first, charge battery, installed new plug, and changed oil, removed carb checdked and cleaned, foudn no debris, reinstalled, started, but very rough idle, off idle its okay. I would remove the plugs (all 16) and inspect them carefully. After that I get misfire trouble codes. Even if you spend extra cash on the best iridium spark plugs and install them expertly, if you don't replace the spark plug wires at the same time you're probably wasting both time and. I took it for a ride around my block at about 30mph and it idles really high like 1500 rpm then applying the brakes at a stopsign it goes back go the rough idle. My car has a manual transmission. How to change your spark plugs; Symptoms of bad spark plug wires include a rough idle, a noticeable drop in engine performance, and lower gas mileage. What Tests Can I Perform to Find the Cause of the Misfire Condition?. It looks different than V8 - I just removed the 7 bolts that hold the coilpack down. Standard copper spark plugs last up to 30k miles while iridium and platinum spark plugs can last over 60,000 miles. I'm not 100% sure what plugs are in there. Look at the air cleaner. I forgot to check it in the rear, and suddenly remembered about it after putting the intake back together. now i dont let my get as bad as some people do. Just like the other person with the jeep my 2007 Elantra GLS idles very rough with these plugs. Start the engine and see the color of the spark. So I decided two give it a tune up, changed spark plugs( motorcraft plugs) and non of them broke either. Spark plug/spark plug wires. one thing i figured out that the temperature sensor got disconnected and that caused the truck to stall. It only takes a minor problem like a fouled spark plug to cause your engine to vibrate. HowTo: Sea Doo Running Rough? Change the Spark Plugs First 28 This entry was posted in DIY Reference Sea Doo and tagged DCPR8E dielectric engine running rough losing power replace replace spark plugs RXP Sea Doo spark plug on July 10, 2013 by Steve Jenkins (updated 1574 days ago). A carburetor has a lot of parts in it that consist of “soft” materials. A spark plug that fails to fire can cause an issue as simple as a rough idle to something as serious as a no-start. If you suspect that your carburetor has a blown-out power valve, you can perform this simple test. The moment of truth is fast approaching. Get your car ready for cold weather driving before you have a problem. Check that your plugs are screwed all the way in. 4 spark plug problems have been common on models from these years as well. DIAGNOSE – ENGINE IDLES TOO HIGH. The problem is that the engine will not idle properly, it runs rich and i can smell it from the exhaust. Due to the different tip design, the gap of the spark plug has also changed. A vacuum leak on a fuel injected engine will cause high idle. This is extremely apparent when I drive up hills slowely. A fresh plug versus a worn out one. They are not suppose to wear down. Copper plugs, for example, have the shortest life, while plugs made of more advanced and durable materials can provide up to four times the life of a copper spark plug. Hi all I heard alot of rumours that when you change a spark plug it increase your engine power is it true ? i had a friend who change to denso iridium sparks on his vios and he feedback to me that his car feels more powerful. when i changed the spark plugs it started doing the same thing. i tried 2 different brands of copper -- champion and bosch, WTF! i just changed spark plugs and now it idles really rough - JeepForum. Just get standard Bosch or NGK copper plugs. I'll share with you Misfire testing and troubleshooting techniques. Spark plugs create the spark that is needed for your car to burn fuel. Also broke the egr valve in the process, replaced. A rough idle on a Nissan Altima can indicate that you need to change your spark plugs or you need to check your distributor cap. Wow, this is pretty interesting. Next was the TSB for rerouting plug wires, no change. I just installed Bosch Platinum +2 spark plugs in my 1996 Volvo 960. and I replaced the spark plugs. Models that have been made since 2010 have a focus on safety features. What causes a rough idle? A rough idle can be caused by many different car faults. Having rough idle/engine light issues with my '09 Mini S (47k miles). replaced fuel filter 4. How to fix a rough idle/clean, Customer Replaced Spark Plugs And Now It Runs Bad!? - Duration: 9:21. However since I have changed them the car is idling pretty rough. I changed the filters one night, ran just fine. I forgot to check it in the rear, and suddenly remembered about it after putting the intake back together. 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. Since you have the 1. * changed the sparkplugs (since PO last changed them about 3 years / 30K miles ago according to service records and I didn't know which ones were used) * now I have very rough idle and when I put it in Drive it sounds like it wants to stall * "Service Engine Soon" light on the dash is now illuminated * no backfires though WHAT I CHECKED:. Just because they are bolted on tight does not mean they are installed right. I changed the spark plugs, plug wires and coil pack. I wouldnt pull the spark plugs out unless the cel or engine gives you problems or fuel mpg goes down. Sometimes a lean condition will cause a “hanging” idle that is slow to settle down to set idle speed. Don't let routine maintenance fall to the wayside. The spark plugs bridge a gap between two electrodes in the engine that allows fuel to be transported to the engine by the ignition of a spark from the spark plug. Making it run faster won't fix it, it might hide it. I just changed the spark plugs from NGK platinum 5 heat range gapped at about 0. Fuel and air comes from the fuel system and carburetors. 5 volts with engine running at idle. i changed my spark plugs now my car runs rough? Car runs rough I checked The fireing order its correct we made sure all the plugs were on now if I'm sitting at a light it idles really hard until I press on the gas then it acts like its hard to go for a couple seconds please help me I need my car. Please help, Changed spark plugs in 2006 GT, now it's running rough! My 2006 GT just hit 70k miles so I decided it would be a good time for a tune up I did my research here about the plugs breaking and whatnot before attempting to change them. I suspected the alternator, so I checked it out, but it's actually putting out 13. Make sure you did not pop a hose out of place. Rough idle, poor fuel economy, engine knock (a thump from the engine bay accompanied by a lack of power. (6) Adjust your driving habits. I have driven both 1. Remove each spark plug, ground the threaded base against the engine block and, with the spark plug wire connected to *only that plug*, have a friend crank the engine. After a week ok, then the engine became rough idling and check eng. The most common symptom of bad spark plugs is engine's starting troubles. Try swapping the spark plug wires out one at a time or check to see which plug is not firing bu removing the splug wires 1 at a time while the engine is running or sometimes you can get lucky and read the plug but that can be diffcult since the problem only happens at idle and that's typically not enough during a short duration to cause a plug. Make sure mice or bugs haven't gotten in there and built a nest, plugging up everything. 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). Spark plug/spark plug wires. I just changed the wires and plugs on my 94 buick regal 3. P0304 and P0351 are common DTCs associated with faulty spark plugs, but you will know if you need to change the spark plugs if you notice any of the accompanying signs, including rough idle, engine surging, lack of acceleration, and high fuel consumption. Though it is an improvement because, before the change, air temp didn't seem to affect the idle. Many system malfunctions can cause misfires or rough idling. I have a 2004 1 litre VVTI Yaris. Dealers are notorious for starting cars, moving them fifty feet, and shutting the engine off. Now you should be ready to get started. What cam? And at what rpm was the 20* initial measured at?. i saw that gear marks were correctly aligned. Old spark plugs that cost you performance like MPG are bad for your wallet. Step 3 - Once you are done, replace the grommet and take a good long run on the bike. For instance, if it has platinum or double platinum spark plugs we would recommend replacement with the same style of spark plugs since this is what the vehicle manufacturer engineered the vehicle to use. 1 Spark Plugs. My 2005 Scion xA now runs rough after oil change. After I was finished it is running much worse than I stated!! Almost feels like its misfiring, rough idle and shakes when I accelerate. , what i found that ecu give them an electric pulse and after 10 sec. I changed the plugs and oil yesterday. Even if you spend extra cash on the best iridium spark plugs and install them expertly, if you don't replace the spark plug wires at the same time you're probably wasting both time and. Any advise?. Was a problem found? — Go to Step 24. A rough idle on a Nissan Altima can indicate that you need to change your spark plugs or you need to check your distributor cap. I also had to get a new coolant temp sensor (napa) because the old one broke. It looks different than V8 - I just removed the 7 bolts that hold the coilpack down. Changing Plugs, Wires, Cap And Rotor on a GMC Torque directly affects the spark plugs' ability to transfer heat out of the combustion chamber. Changed the spark plugs and now idles rough, we just changed them today. The plugs i used are SP515 ( MC brand from Ford Dealer ). If the old spark plugs are real clean you can use them, otherwise put in new ones. The rough idle could be because one or more of the coil-packs may not be properly seated on the spark plug head. Page 1 of 2: How to troubleshoot a hard to diagnose misfire case study. Spark Plugs. The fuel tank should be emptied. Problem: When in idle, motor has a miss/stumble every few seconds. Dirty fuel injectors. If i remember correctly, i coulve sworn i saw 1 drop of oil fall down into the cylinder (spark plug was still in the cylinder). 4L truck engine in mind, but it also applies to the 4. My car has a manual transmission. I gaped them properly. AutoZone is the best place to buy any parts you need for a tune-up. It must do this at exactly the right instant and do it at the rate of up to several thousand times per minute for each cylinder in the engine. Car still feels a tiny but rough at idle but I'm still digging into this car to see what's going on atleast the RPM problem is solved. i tried 2 different brands of copper -- champion and bosch, WTF! i just changed spark plugs and now it idles really rough - JeepForum. ok,,truck is running so rough after changing the spark plugs ( only 1 of 8 broke, thanks to the info provided in this forum ). NGK Iridium IX Performance Spark Plugs feature a copper core electrode for its superior conductivity and an iridium tip (which is 6X harder than platinum) for its extremely high melting point, perfect for keeping your Mustang's high-performance engine running at its peak. Making it run faster won't fix it, it might hide it. if you find that the engine tone doesn't drop much or at all when one of the leads is removed, pull that spark plug and have a look at it. 3 V6 non SC It idles rough. Like the air filter, the spark plug is extremely important to a functioning lawn mower, yet inexpensive and easy to replace. 00 tuneup was spark plugs. Gen 8 Malibu, Years 2013-2015 and 2016 Limited. Misfires after changing all spark plugs and coil packs cold start is still rough, along with idle. I also changed the fuel filter and treated tanks for contamination. replaced fuel filter 4. Now the engine seems to idle rough. Still, plugs fail over time and there’s not much you can do about it. Today I decided to change my spark plugs, I figured I have had this car for 2 years, I think its about time. Small Engine Troubleshooting. So I decided two give it a tune up, changed spark plugs( motorcraft plugs) and non of them broke either. If your plugs indicate that something is seriously wrong with your engine, ask a professional for an opinion. Gen 8 Problems/Service Issues/Troubleshooting. It started easily and ran fine; but the next time I used the mower, it was hard to start and ran poorly again. I changed the spark plug on my old mower without problem, but now I have a mower I bought last summer and it has a very long snug boot that I can’t get off my spark plug. I have decided to order a set of NGK's instead since it is very rough. I have just replaced 6 new ignition coils and 6 new spark plug. While these cars typically maintain good drivability otherwise, the rough idle seems to be traced back to spark plugs. Is there anyone that can help me/ explain me how to change the spark plugs for 2001 Aurora 3. I can feel the truck shake a bit feeling rough while idling at a stop light. replace spark plug lead remove spark plug lead #3 and listen for drop in engine tone replace spark plug lead remove spark plug lead #4 and listen for drop in engine tone replace spark plug lead. After changing the plugs the problem still exists. A quick Google search revealed basic tune up (Spark plugs, COP's, Rotor/Cap, Fuel Filter). The problem is that the engine will not idle properly, it runs rich and i can smell it from the exhaust. How to fix a rough idle/clean, Customer Replaced Spark Plugs And Now It Runs Bad!? - Duration: 9:21. Be sure to check the polarity of your coil. Plugs containing the suffix TS or CTS can be used interchangeably. RE: rough idle IP: Logged Message: I have a 93 dodge dakota that wont stay running rough idle and shaking sounds like it sucking. This meant changing the spark plugs, checking the resistance of all the spark plug wires and finally, checking the ignition coil primary and secondary circuits with an ohmmeter. Pour a tablespoon of raw gas in the spark plug hole, replace the spark plug and try it again. One thing you can do in before changing the plugs is run a bottle of Quickleen thru your Opti. 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. Issue 4 – Loose gas cap. The most common symptoms of Bad spark plugs are rough idle, rough acceleration, misfires, hard starting condition, poor fuel economy and you will probably experience a Check engine warning light on your dashboard. ) Coil weak or intermittent - you should see 3/8" fat blue spark with a good coil 3. Engine light is on and the traction control service message is on and engine runs rough after I changed wires and spark plugs today. Just because they are bolted on tight does not mean they are installed right. Spark plugs use the electrical current received from ignition coils to ignite the air/fuel mixture within the combustion chamber. Page 1 of 2: How to troubleshoot a hard to diagnose misfire case study. 040", but mine was. I tighten them to 21 lbs-ft. Changed the plugs with the recommended OEM plug, CAREFULLY, and perhaps obsessively. A spark plug that fails to fire can cause an issue as simple as a rough idle to something as serious as a no-start. Decided that I should change plugs. Your Engine just started acting up and you don't know what to do. These problems range from easy to change coils, to the dreaded spark plug, all the way to the scary and expensive timing chain issues. Double check those to make sure they are seated properly. The car seemed to run better to me. Oookay, so the new MFI is in place and it's STILL running rough So I have them checking the distributor now too, haven't heard back from them yet. Drove a mile and on idle it ran really rough and the exhaust was "puttering". Let me say right up front, the truck seems to be running fine! Drove it to town last Friday. Problem with Lawn Mower Engine Running Rough My lawn mower was running rough, so I changed the spark plug. RPM fluctuate from 615 to 300 and back within 2 second. Dodge 440 engine problem???? sandy: 8-4-05 : Recently purchased a 1978 Itasca with a Dodge 440. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. A rough idle could simply be the result of an incorrect idle speed setting. I have a 2004 1 litre VVTI Yaris. to change them. Your engine could be idling roughly due to a number of different reasons. Pour a tablespoon of raw gas in the spark plug hole, replace the spark plug and try it again. It does not seem to run as smooth as it did with the old spark plugs. A spark plug that fails to fire can cause an issue as simple as a rough idle to something as serious as a no-start. Problem with Lawn Mower Engine Running Rough My lawn mower was running rough, so I changed the spark plug. When it comes to Ford 4. If a spark plug tip is white, then the engine runs lean. Once your spark plugs start to wear out, your car's performance and fuel economy will suffer, and your engine can begin to run or idle rough as well as use more fuel. A fresh plug versus a worn out one. Anyone else got some insight on this one? Need all the help I can get. READING PLUGS. The Spark plugs are an important part of the engine and it could cause a lot of problems. They can last much longer, but when they go bad, you'll spend much more time and money on the repair than you would have on the prevention. No oil in the coolant, and no smoke from exhaust, it isn't overheating, either. 3L with 100K miles on it. The misfire is caused by having different metals and the coil trying to fire both plugs. When pulling a full rated load (9600 lbs) at highway speeds the truck shudders slightly as though it. 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. 3L with 100K miles on it. 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. One reason for a rough idle is it could be time to clean out the fuel injectors or it could be time to change out the spark plugs. Engine has a rough idle. The misfire is caused by having different metals and the coil trying to fire both plugs. Now, I have a rough/surging idle when it is in gear sitting at a stop up to about 5mph. Small Engine Troubleshooting. 622, 112 LSA using HP Tuners. The new spark plug, P/N 12571164 with AC Delco P/N 41-985, is gapped to 1. The addition of an extra coil allows the glow plug to have a "self-regulating" feature. (Needed warm weather, brother-in-law and room in the garage. Daihatsu - most models Surging, cutting out & runs rough. I can feel the truck shake a bit feeling rough while idling at a stop light. I took the car to the dealership, they pull the spark plugs wires, noticed that all the spark plugs are working, they suggested to remove the intake manifold to check the injectors for only $370. They regapped the plugs and all is well, plugs basically had no gap. I have a 2000 Ford Expedition 5. We recommend using the BlueDevil Head Gasket Sealer to help seal your leak.