Mustang Rough Idle Low Rpm Misfire

It was tuned up 2 months ago changed fuel filter and when we took it out a lot of air came out instead of gas. Ford Mustang V6 2005-2014: Why is My Check Engine Light Flashing? A flashing check engine light is a good reason to worry. Took it to a friend with a scanner because it had a check engine light on and the code was for cylinder #8 misfire. 60 with similar if not identical results. the check engine stays on and when in park, same problem with the idle bouncing up and down. 00 vacuum line. It even feels like the power steering gets heavy. when i put in drive (c4) it dies. The car also is running rich. It will start and go for about 1500 rpm which it does when it is cold, after a few seconds the rpms start to drop and it runs really rough, it will then hunt for idle bouncing up to about 2k then drop back down to a few hundred rpm and die. Spark Plugs. The 98 US WSM lists the following possible causes for "Idle speed too low and excessive engine shake":. can low grade gas cause a misfire, I don't think so but, Contaminated (water, etc) gasoline could. It doesn't seem to do it until the bike is warmed up. After about a minute after starting it, it begins running really rough and rich like a cylinder isnt firing. It can be felt at a stop light idleing, some times the RPM needle will boune around a bit, and you can fell it if you were to lean on the truck. The 2003 Ford Explorer has 5 problems reported for engine idles rough. Lately the kk has had minor stalling issues upon decelerating and stopping the rpms drop to around 500 causing the ac fan to reduce power like the engine is about to shut off. The plugs have been replaced three times. I just seen another post identical codes and Identical symptoms idle and low speed misfires go away about 3000rpm and WOTit was like reading a journalhowever HIS was the IMRC cracked issue yet mine has identical issues and codes with a TVSnothing he did resolved it. Rough Idle 99 Silverado 5300 its a vibration and not a misfire. OK i have a 1960 Ford Ranchero with a 200ci i6 and after I tun the ignition off it still runs at its idle speed of about 600 rpm. If you haven't already, research the term "IAC" which stands for Idle Air Controller. How is a non-accredited university recognized or. It is my daily driver and I do some spirited pulls about once a week. Search the history of over 376 billion web pages on the Internet. I've got a 97 silverado with a 5. My mechanic seemed to think there might be a timing chain noise and the guides could be worn some. Unless it's leaking but that would cause rough at low idle which is not a problem for me. This information is from various sources, like my experience, AFM, the Ford Fuel Injection Book, other site members experiences. Components in the fuel, ignition, emission and other systems should work correctly. We changed plugs/ wires and a new coil - Answered by a verified Ford Mechanic. Started and ran fine going to town. No codes associated with misfire or anything. If I keep it from reaching that low of an rpm, it runs perfect. Raul Garcia. When traveling at low speeds, 40mph and/or if the RPMs are below 1800, the RPM gauge jumps and I can feel the surging. 2008 Mustang GT, 4. From the description you have provided, for the P0301 rough idle and heavy misfire and P0456 evaporative small leak detected, the problems are unrelated. his Mustang was plagued with a definite misfire and rough idle. i can't figure out what else could be wrong. 68 Coupe, Edelbrock Carb. As far as the shaking goes it sounds like a misfire. Update: Not the front o2 sensors. If too much air gets mixed in with the fuel, it will cause your engine to misfire. 2300 and 3000 rpm. This can cause a very uneven idle which can jump up and down and the engine may also shut off on idle. Heres what my issue is like. It will go from normal to a low idlenot a rough idle and it doesn't act like it's going to shut off but a definite low idleprob around 350-400 RPM. Anyone know where I can find a diagram or other thoughts? Thanks. there are two screws in the assembly that regulate flow, and sometimes these are known for building up carbon. No code was set, but she ran terribly, with no power, major misfires, and an occasional backfire. It starts fine, although the idle is very rough the truck shakes in idle. The car started and everything was find at first then started rough idle only on idle and pulled out of it as I pressed the gas pedal. I'm not getting any engine light, and I know it would turn on if there was a misfire, but since its been fixed, I'm still feeling the shakes and what I can only describe as a slight kick. I do some more research, and try cleaning my MAF. Be aware I swear twice. " This would be mixture leaning out, or the spark becoming intermittent. it runs fine when i first start it, but soon idles low/rough, but only in gear. If misfire happens only at idle, the EGR valve and purge valve need to be checked, as either one could be stuck open. Even before I put the dumps on it, you could smell fuel if you sat somewhere for over about 5 minutes. Type B detects a condition that is progressing over time. What is the best slogan for''When we are immune''? 276 want this answered. I loved the rough idle but I didn't like low rpm roughness when driving through the city. Vacuum leaks can be found with a smoke machine, soap + water or with a flammable spray. Ford F-Series Rough Idle/Vibration Problems I cannot get the truck to idle below ~ 1200 RPM = to 45 MPH unless it downshifts to first gear which will then allow. a third cylinder misfire code in i let it idle down then it clears itself after a day. My car: 2011 GT Premium -3. KOEO: 85 85 13 14 66 91 96 31 41 66 91 96 KOER: 21 41 91 33 21 41 91 33. Goes away completely above about 2200. The next morning, she was a little hesitant on start-up, but ran rough with no stalling — and no Check Engine light. Felt like a misfire, so I replaced plugs and wires. Oh also it has a stutter at low rpm (1200-1800) at a very very. 3 is now 4 months old and has done almost 5000 km. Plugs have been gapped at. The feeling is vey similar to the sensation of a tire out of balance. Lately the kk has had minor stalling issues upon decelerating and stopping the rpms drop to around 500 causing the ac fan to reduce power like the engine is about to shut off. I have an 87 Mustang GT, 5. I had idle misfire on my '03 DOHC for at least 6 months and no codes, no pending. " This may only need a minor adjustment for timing or mixture. Car started missing/ hesitating at low rpm under load, with a rough idle almost as if it was cammed. I checked everything and everything seems to be secure and in place. the catalytic converter was clogged, so i replaced it with a magnaflow direct fit and it installed with no problems. Possible cylinder head or valve damage on the GM 2. - sporatic idle I'm going to plug that fuckin valve tommorow and see if that's the culprit. - - 1966 mustang v8 rough idle / misfire (https: I recently rebuilt the engine of a 66 mustang v8. Once it begins to idle back up the idle goes back smooth. This occurred no matter what the temp was. I have just recently noticed a slight hesitation or misfire from the engine while the car is in drive and the brakes are on. I am experiencing a rough idle at low RPM's, it mostly happens when I am in 1st Gear or Reverse. When the cars idle gets rough, it hard to comprehend the related causes. Rough idle, misses erractically, lopes. - sporatic idle I'm going to plug that fuckin valve tommorow and see if that's the culprit. Even a dirty MAF sensor can cause a lean code and/or misfire to occur. The points system has been replaced with electric ignition and set timing, cleaned up all the vacuum leaks, and replaced the old Autolite 2100 with a new Holley. The car started and everything was find at first then started rough idle only on idle and pulled out of it as I pressed the gas pedal. Mustang Monthly Magazine shows you how to tune your vintage Ford Mustang for improved performance. Car will shake. It shakes until I reach a point, and then stops for a few seconds and starts again. 8 running rough (MUST CHECK THIS Mustang Idle Problems 5. If it does, a fuel pump with more capacity may be required. My best guess is that the factor idle setting is too low and the electronic ignition is fighting against the torque converter. I'm not even sure if that's bad enough to worry about but I figured it might be related to the idle issue. I consider that fairly low, but it's nothing like 6 speed corvettes that can run 60 mph at 900-1000 rpm. So I get it replaced, put the new one on and it drives REALLY smooth but the idle was really bad. I have an 87 Mustang GT, 5. When cold it seems to run fine. When warmed up its idling closer to 500 rpms. Rough idle 3 Answers. It didn't have any codes and had no mechanical issues. Recently replaced the MAF sensor to correct another problem, but still idles rough. So here it is in full glory my car with its weird issues. Chances are that if you fix the misfire; you’ll also repair the rough idle at cold start. I have a 2007 Rav4 4WD 4cyl 2AZ-FE engine w/ 66K miles on it and I am plagued with a rough idle after complete warm up. Search the history of over 376 billion web pages on the Internet. The misfire monitor runs continuously when the engine is started. The engine light came on yesterday, and today its started blinking after warming up a lot going up a hill and it seems to be warming up way too quickly so I touched the radiator and it was cold, but hoses were warm leading to the motor. runs rough 2000 mustang 3. It may or may not dip down low enough to be rough again, it varies, but in the last couple weeks it has done it for about half of the stops I. We'll walk you through how to properly diagnose and fix a flashing check engine light. 8 automatic. If it does, a fuel pump with more capacity may be required. All engines at one time or another will have idle problems; Ford engines can have idle stumbling, surges and stall-outs, no matter what make and year. At IDLE, there should not be any more than 5. Both conditions can cause a P0171 lean code, rough or unstable idle and sometimes even a stalling condition. While there are a variety of reasons your Ford Mustang has a rough idle, the most common 3 are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil. Starting, car starts right up and jumps to 2k rpms or whatever when starting, and when its settling back down sometimes it will just die, otherwise idle will drop extremely low to the point of it not registering on the tach, and then idle back up. I normally keep low idle around 800 and high idle around 1200, works well on my '73; it is also the easiest thing to check. Every now and then I get an extremely rough idle. The truck also stalls in reverse and struggles backing into my driveway it also struggles in drive when i am in low rpm situations like in parking lots or going through a drive thru. The V2 isn't a lot different than my SS HT. I've had problems recently with my '03 vibe running real rough. The coupe with the 351 Cleveland I just picked up, when its idling it idles rough and raises the RPM off and on but sort of in a pattern, when I'm driving it seems like it surges between 40-45. Idle was always 650 and was never above or below by more than 100. gets better @ high rpm 2004 Chevy Malibu with a 3. its sounds like an Idle Air Control (IAC), these are very common on fords to go bad, and they are also very easy to change on mustangs. Ford F-Series Rough Idle/Vibration Problems I cannot get the truck to idle below ~ 1200 RPM = to 45 MPH unless it downshifts to first gear which will then allow. This problem has been getting worse over the last 2 years. how do i adjust the idle on thi smotor i am new to the 5. The idle might smooth out for a minute or too but then gets really rough again. The short answer is an imbalance of fuel and air, improper spark, improper isolation or mechanical damage that has caused the engine to vibrate. I'm not getting any engine light, and I know it would turn on if there was a misfire, but since its been fixed, I'm still feeling the shakes and what I can only describe as a slight kick. 5l dohc misfire/rough idle Contour Car Forums around 900 -1100 rpm somewhere in there, however it's still rough. When revs are at about 1500rpm, I put my foot down say 20% throttle, it misfires once or twice until revs climb to 2500rpm, then will rev without missing all the way to redline. changed tps cleaned iac no change any help would be great! because im lost. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc. A couple of weeks ago Ive noticed that there is a slight hessitation at idle. 98 Evenrude 150 Ficht- misfire- injector of plug wire? a little hesitation in idle and low RPM- perhaps a misfire is a better word. It's an '03 GT, idles pretty rough with an audible misfire. 00 vacuum line. I have one more Vac line to check, I think it is a line running down to some sort of fuel vent but not sure. The engine may only misfire and run rough when cold but then smooth out as it warms up. Idle is most rough, when the engine is first started in the a. (should have said that sorry) its been into the mechanic but they couldnt get it to run rough in the test tank so hard to fault find unless on the water i guess (still charged $$$$$ so cant afford to continually put it in the shop). When it reached 1500 RPM it runs smooth and when I stopped on the stop light it idles rough. Yes the bike hasnt been running that much this year , but has had some long rides, and plenty of full throttle. I can put it in park or neutral and RPM increases (as it should), but the idle quality is still less than desirable. Vibrations. Tech Tip: Multiple Cylinder Misfire or Rough Idle on Chrysler Models This bulletin involves rotating all ­engine exhaust valves, replacing the valve spring retainer locks with a new design to increase valve rotation at lower rpm, inspecting/replacing the MAP sensor (as necessary), and decarbonizing the combustion chamber. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc. Spray that area again, and you should hear the idle RPM change. There is an idle circuit in the rear barrels of your Holley, too. the engine has a rough idle. Pulled into Autozone and scanned P0300, P0301, P0305. Any ideas?. yeah my cruise control works and the car will not shut off it just bucks like a bull, as long as im giving it gas its fine i can be going 40 in 5th and it runs smooth, only when i let off the gas at low rpm's in gear does it do this it idles and accelerates great it has about 350 miles now and has plenty of power i stomped a 87-90 5. The intake manifold O-ring gaskets commonly leak, which creates a large vacuum leak. It seems to stumble a little bit at low RPM. This setting can be easily reset using a butterknife or similar tool. I have a mild E-303, ported TFS heads, Holley intake and a 70 mm throttle body. Misfires are probably one of the most common reasons when it comes to rough idle. Let me know if you need details. Has anyone else experienced rough shifts up and down, rumble strip feeling on decel, shudder on tip in acceleration and slight shudder at low RPM regardless of speed or gear? Probably the worse AT I have experienced. Mustang DTC Codes. This information is from various sources, like my experience, AFM, the Ford Fuel Injection Book, other site members experiences. Intermittent misfires can be a real challenge to diagnose, so let's start with a steady misfire in one cylinder before moving on to intermittent misfires. Mechanical misfires. i took it to a ford dealer and that was the fix. Engine Misfire. first off, to the person who answered first, mustang GT's stopped using carbs in 1986. when in drive, the idle is at 1500 and wont come down any lower (even with a warm motor). I bought my Jeep with a blown radiator, replaced that to find a very rough idle which goes away at 2000 rpm cold and 1500 rpm warm in neutral and it goes away almost instantly when driving. The new code is misfire in 1,3,5 cylinders with low current in 1,3,5 injectors. Car starts up fine but now has a misfire on that same cylinder. - misfire under light load - fine at WOT - sluggish at times, strong at others. Mixture screws let you adjust the mixture of this circuit. 6L Rough Idle/misfire. It's an '03 GT, idles pretty rough with an audible misfire. 5L engine may exhibit a rough idle, low RPM at idle or a stall on hot restart with no DTCs in self test. The RPMs would hover a notch below 500 and when the rough idle would kick in, you could see the RPM needle jump up and down. RPMs will fluctuate quite a bit and then settle down. At idle, the engine most definitely had a miss and would stumble now and again. 2005 Ford F150 stalls at idle and surges Recently we came across a 2005 Ford F150 with a 5. from what i heard its because the ac compressor needs extra power so the IAC tries to get the idle to go higher but since it doesn't work like it suppose too it makes the rpms go up and down real bad, when i turn the ac on when im idling the rpms go up but and down but it doesn't get real low it gos from normal about 800 rpms to 1000 rpms and lower. And at the exact moment it occurs, the engine makes a terrible farting/roaring sound that is just like diesel truck engine braking. Until today, the car engine (when cold) started and then the idle revs fluctuated occasionally between 800-1200rpm until the engine has warmed up a little (2 minutes or so). High pressure oil flow can be disrupted by faulty check valve(s) or a faulty Injector Pressure Regulator (IPR) valve. Yes the bike hasnt been running that much this year , but has had some long rides, and plenty of full throttle. Rough Idle - Random Misfire - Erratic RPM. It doesn't seem to do it until the bike is warmed up. " This may only need a minor adjustment for timing or mixture. >"but upon acceleration at high rpm it misfires. Thank you so much for the help. Figured I'd share this since I've seen a good amount of people here complain about a rough idle. At Highway speeds it is fine, and it will rev fine too. I'm in the process of running this in. It couldn't hurt to clean the TB and MAF, and maybe check the plugs if high mileage. If you rev it to 1000 rpm it doesnt misfire or stumble. The RPMS bounce around a lot when in Drive (in N or P it idles smoother with the higher RPMS). I am experiencing a rough idle at low RPM's, it mostly happens when I am in 1st Gear or Reverse. It's clean, but no luck, so I change to the old ignition coil pack and now it drives smooth but idles rough. I have an 04 Grand Am and it is running rough at idle so I hooked up the scanner in his reading PO 301 and PO 171 I just changed all of the spark plugs but still reads the same codes. Unstable idle speed. Not only that, but quite a few things can cause a misfire condition (or misfire trouble codes). Rough idle problems are really common on BMW E36 cars and there are a lot of problems that may cause this to appear. 1990 Mustang 5. It also idles rough aftter getting off of the hiway and having to sit a a red light. Re: rough idle when in gear Post by frankyhalo » Fri Mar 12, 2010 10:37 pm I had this problem and it was a vacuum line, dont remember which one but one of the ones right on top the motor. We changed plugs/ wires and a new coil - Answered by a verified Ford Mechanic. Misfire and Bad O2 Sensor. When the engine is at low RPM, anything below 2K it's an intermittent mis that can be pretty violent unless I ease off the throttle. Rough idle and light backfire. A worn or dirty spark plug is the first thing to inspect. Consistent. Replaced wires, cap, rotor, plugs, coil, and TFI control module. Top 10 Causes of a Rough Idle | JL Motorworks. It jerks every few seconds and there is no pattern to it. Drove it for a few days and it would misfire at idle but accelerate with out hesitation then for a few days it cleared out, well I moved and didnt drive the car for about another 4 months, then when I came to move it I tried to turn it on and the motor would turn over start for about 2 seconds and die. It failed the low idle portian of smog but was clean at the higher rpm portian. Misfiring after installing a thread insert in cylinder 3. I have a rough, low idle "about 700 rpms" although the inductive timing light says otherwise. When running down the road at a steady speed and fairly low RPM, say around 2500, every once in a while the bike will have a very sudden and slight misfire. Boat engines have the same operating principles as do land vehicle engines, but having trouble with your boat engine can leave you and your family in a precarious predicament. The Ford Mustang, with the 4. The truck also stalls in reverse and struggles backing into my driveway it also struggles in drive when i am in low rpm situations like in parking lots or going through a drive thru. My Snap-on Modis scanner revealed a coil driver code, so I went out and checked the coil driver circuit, plugs and wires, and coil itself. I checked the fuel pressure at idle, it's 32 psi. Has new injectors,distributor and most every smog part is new except the air pump. What is the best slogan for''When we are immune''? 276 want this answered. - misfire under light load - fine at WOT - sluggish at times, strong at others. 8l E-150 No check engine light. A faulty spark plug wire that arcs through the rubberized spark plug wire or bad spark plug boot which can cause your 4cyl. Almsot like a vacuum leak rough idle. The vehicle starts w/o issue but in gear or park it has the rough idle. Such symptoms have to be checked out, determining which vehicle components might. The P0300 is a random misfire code which could be caused by many things, like spark plugs, coils or something like a fuel pump which could affect all at once. 97 tj low rpm miss and rough idle. 5L HO and recently I have gotten a code for Cylinder 5 misfire (P0305) and now it is starting to idle kind of rough and even shake or shutter after I come to a stop at an intersection. I have been chasing a rough idle on a 2002 Seville SLS. They called techs at Dodge, who suggested the low idle was likely a software issue but otherwise the car was fine and that the thump/vibration may be the exhaust being rough due to the low RPM. Car will shake. Jump to Latest Follow 1 - 13 of 13 Posts (2. A couple of weeks ago Ive noticed that there is a slight hessitation at idle. The P0301 is a #1 cylinder misfire code. Ford Mustang V6 2005-2014: Why is My Check Engine Light Flashing? A flashing check engine light is a good reason to worry. My check engine light came on about a week ago and i brought it to the parts store because they do the diagnostic test for free. The vacuum is hooked up to the ported inlet on the. - Check (idle) throttle switch - Clean sensor plate or airmass sensor & throttle body orifices - Change the fuel filter - Clean idle stabilizer VALVE with brake or carb cleaner (VW&P) (Note: Earlier cars had a Digital Idle Stabilizer circuitry (DIS) which is something different, and *rarely* fails). Diagnosing the cause of the misfire (rough idle) on a 2. Several here have had ongoing issues with misfire codes. The 2003 Ford Explorer has 5 problems reported for engine idles rough. Anyone have one of these, with a similar problem? Any sugguestions? ratherwhalering: posted 11-09-2001 01:03 PM ET (US). The number one cause for high idle is an imbalance in air pressure. Raul Garcia. P0300 (and P0301 & P0302?) Check. Although generic, the specific repair steps may vary depending on. It may appear to work but when the weather gets cold, a high idle will result. a third cylinder misfire code in i let it idle down then it clears itself after a day. his Mustang was plagued with a definite misfire and rough idle. It usually indicates an engine misfire. 2006 STI rough idle and. But acknowledges it is not great. At first, I replaced the spark plugs with stock ngk ek plugs, it ran ok for a while but after the bike warms up, it starts to misfire again near low rpms. When the cars idle gets rough, it hard to comprehend the related causes. Vacuum hoses are cheap. When came back out to go home, (after about 20 minutes), tried to start truck. Remember also that a rough idle doesn’t always meet the criteria for storing a cylinder misfire code. We can now go into more depth on each of these categories and list the different possibilities. >"The engine usually runs fine at idle with an occasional misfire (rarely). Unless it's leaking but that would cause rough at low idle which is not a problem for me. My 2014 Mustang GT started doing this a couple of weeks ago around 22k miles. Login with Facebook. The idle circuit supplies fuel when the throttle plates are open only slightly. We took it for a test drive, it drives well at higher speeds but still. All of a sudden running rough misfires, knocks rough idle. :confused: 2011 LTZ 3. Low RPM could indicate a clogged fuel filter, low gas, dirty or bad fuel injectors. No problems till this morning. Runs better, but still a little rough at low RPM. The intake manifold O-ring gaskets commonly leak, which creates a large vacuum leak. The check engine light flashes when the car is shaking as well. 0l? I have to give my car the "anti-idle surge vacuum leak" and it reads 14 inches at idle, and 16 inches with the leak plugged, surging away. One time I have seen a fuel filter cause a drive ability issue we cut it apart and it had something in it hat looked like rtv silicone and it was floating around and clogging the outlet of the filter other than that these newer cars have to big of filters to stop up and like u said a hundred pounds will push past just about anything then the regulator cuts it down from there I still think it. I have a rough idle and hesistation on acceleration I can't get rid of. But when it warms up it has a noticeable misfire and only at idle. Now at 90K the truck out of the blue starts to idle rough and shortly after the check engine light begins flashing. Every morning when I go to start my car it idle pretty rough for a few seconds then its fine. They called techs at Dodge, who suggested the low idle was likely a software issue but otherwise the car was fine and that the thump/vibration may be the exhaust being rough due to the low RPM. Unfortunately they couldn't replicate the backfire/stall on start-up or the thumping at my feet. Common reasons include vacuum leaks, carburetor problems, ignition issues, damaged power circuits and dirty fuel injectors. -New fuel filter – no effect. Please try again later. They are currently at. from what i heard its because the ac compressor needs extra power so the IAC tries to get the idle to go higher but since it doesn't work like it suppose too it makes the rpms go up and down real bad, when i turn the ac on when im idling the rpms go up but and down but it doesn't get real low it gos from normal about 800 rpms to 1000 rpms and lower. the car runs better, problem solved but my engine still shakes a little when it idles. Remember also that a rough idle doesn’t always meet the criteria for storing a cylinder misfire code. Runs rough at idle and low rpm. CARspec now offers walnut shell blasting of the intake valves to help prevent this issue! 2006+ IS250 and GS300 owners are frequently concerned over a rough idle, especially after sustained freeway driving, or a check engine light with codes P0301, P0302, P0303, P0304, P0305, and/or P0306 (misfire codes). the check engine stays on and when in park, same problem with the idle bouncing up and down. Got it to the mechanic and changed the remaining 7 spark plugs and they were very ugly. Some claim it's just the essex V6. The car when cold runs great. #2 plug wire caused a misfire, but my Ultragage showed wild spark advance ranges when it misfired. At Highway speeds it is fine, and it will rev fine too. The feeling is vey similar to the sensation of a tire out of balance. after it has reached operating temperature it idles rough. Essentially it just means turning the distributor till the engine reves the highest it can without pinging when pulling hills in a high gear. It seems that the average idle RPM is fine, but it bounces around a little and when it's on the low end that's when it "feels" like it's going to go dead. Maybe worn timing chain, plugged exhaust, fuel supply issue? I wasn’t sure so I continued with my diagnoses. I'll even offer an incentive - the first responder to this thread to diagnose it correctly gets some free 944 parts - their choice of a set of fog lights, tail light lenses or a new cam tower cover. Possible cylinder head or valve damage on the GM 2. P0300 (and P0301 & P0302?) Check. The plugs have been replaced three times. Engine 1994 mustang gt Rough idle, misfire under acceleration: Engine '93 running rough, especially at low rpm's and idle. We took it for a test drive, it drives well at higher speeds but still. It usually causes a rough idle and the check engine light will eventually come on. Then it is back to just the rough idle. 102psi #2, 175 #4, 175 #6, low. I have a 2005 V6 Mustang with an added but never used ZEX nitrous oxide kit and an aftermarket Dynomax dual exhaust. 0 stalls at idle. Replaced fuel pump motor only, cleaned tank changed fuel filter and it ran great for about 60 miles. Also, while driving it will misfire and the service engine soon light will blink. Idle problems may originate in a worn out component, a. They are currently at. Resist the urge to adjust the TB set screw for low idle concerns. The car runs well when NOT idling? When you start the car, and press the gas (to bring it above idle) what kind of RPM are you holding it at? Is it running rough at all? Was the carb adjusted?. Such symptoms have to be checked out, determining which vehicle components might. One of the most common problems is likely a rough running or poorly idling engine. engine speed at low idle and high idle is controlled by a. Testing would prove us wrong on both theories. Misfire rough idle. Is this abnormal?. Although generic, the specific repair steps may vary depending on.