Unstable Rpm Idle Motorcycle

From the idle jet, there are little passages cast into the carb that lead to holes just in front of the throttle valve or plate. The stator reads about. low idle stuttering, erratic jerking at various RPMs. It has developed >an RPM surge (800 RPM to 1500 RPM) at idle. Since, in my opinion, the idle rpm should be within the range of ~900-1050, in order to get the early carburetors to work properly (and get proper oiling to the timing chest parts inside the engine) that means some advance will be had even at 900 to 1050 RPM idle on. The CV carb is dependent upon vacuum to function properly.   It seams whichever it is doing, high or low, it does it everytime I idle until I shut it off and then the next time I start it up the idel will be. Normal idle RPM should be 730 plus or minus 50 rpm, but it shouldn't bounce around as you indicate. Sounds like its at about 1000rpm. Unstable, Surging Idle - 383" SBC Engine is a GM crate HT383, roller cam, 196° duration, very mild stump-puller engine, capable of rock steady stable idle @ 600 RPM. One of the potential engine issues is a rough, or inconsistent idle speed. This happens regardless of the temperature and even if I have only driven a few kilometers. For the past 4 weeks I've been having problems with idling when the car is warm and warming up (from a quarter, to half way on the temp gauge). This does not occur when the car is in drive or reverse; it purrs along at a consistent 1200 rpm. Learn what does P0507 Idle Control System RPM Higher Than Expected means, location and how to repair?. It's not easy to get a big cam to idle smoothly at 650 RPM (but it may be possible), so you want to go for something easy first. Below are the four most common. Download Motorcycle Revving sounds 2,815 stock sound clips starting at $2. 1 Full throttle system as usually used on two-stroke engines. It seems that during shifting, the rpm stays at a high rate even though the throttle is backed off, so that puts me at shifting at anywhere from 3 to 5K rpm. 7L 350 V8 in the alt. It is not a fastener, it is an adjustment needle, really). if i shut it off, then start it again. When motorbike is started the rpm are fluctuating between 1500 rpm and 2200 rpm 2. due to lean mixture at low rpm) so in fact this might be a reason they could be colder. I replaced the Idle air control valve since that has caused all my idle problems with my 88 f150. It's a little erratic. When I was leaving, the bikewas idleing a little high, 1150 RPM. That isn't super important unless they jump out all at once. So far, engine and ECM seem to be working wonderfully. Pay attention to low idle or stalling. Fixing an Erratic Idle By: Adam Pilchack Let me give you some background on my del sol if you haven't been around long. It cranked for a while, all the while it seemed to be jumping up and down a bit (Literally). About 150 mph. ford galaxy v6 - erratic idle 800-1000 rpm - elekie&a/c doctor : You need to be checking all the air intake and breather hoses for possible leaks. high for a few seconds and then settle to the idle rpm then the carbs are adjusted towards the lean side. I've only driven it twice since I bought it, but when I took it out today I noticed the idle speed was not constant. After the fact, when I mentioned the high idle the previous owner mentioned that it had been doing that for awhile. Having a little trouble with surging/loping idle on MTD lawn mower (#11B-106C401) with 6. It has been very reliable and recently smogged easily, but the idle has become erratic with throttle surges at idle in park that are very noticable on the tach. When I went to leave there, the idle was now up to about 2000, by the time I got to Van Wert it was up to about 3500. Motorcycle Carburetor Problems. Idle Air Control Circuit Low. Damage to the car's carburetor and vacuum hoses can cause the engine to misfire, resulting in a rough idle. This puts a good load on the motor and is an accurate test of performance. I took it to the dealer and the head mechanic who has been working on Kawasakies for years said that even the carborated models can have this particular miss between 1000 and 1300 rpm. When I returned from my summer ride (9300 miles), the engine was rough running when the throttle was applied above idle. Your engine's optimum idle speed is the RPM that allows the lowest possible engine speed while allowing a stable idle. " Just try that. I bought a Honda powered 17 HP Sears Craftsman lawn tractor two years ago. That parallel Twin engine is actually pretty okay. One of the potential engine issues is a rough, or inconsistent idle speed. The vehicle in question was a 3. My truck still gets the erratic idle when coming to a stop. Then turn the air-fuel screw clockwise a little about 1/8 turn then stop. The electrical circuit of a motorcycle is basically similar to that of a car. Tumataas talaga ang idle speed ko. My L7R have the following mods :Arrow SS headers, Pipewerx silencer, Bmc airfilter and woolich racing package. Went to synce them and while trying to sync the idle will jump from 1k RPMs to 3k or 4k RPMs. Below are the top 5 causes that a mechanic would look for. ZRX1100C Unstable Idle The cause was a leaking fuel pet, causing fuel to enter carbs, thus over time, flowing into the # 3 cylinder thru opened intake valves. At the first cold start-up, the engine idle did not elevate to the normal ~1400 RPM, instead it immediately went to the warm engine idle speed of about 750 RPM. Warm Idle Speed = This is the Target Idle RPM for when the engine temperature reaches 170 degrees Fahrenheit. However, that early version allows some small ignition advance from ~800 rpm. All we can set is the idle RPM. This puts a good load on the motor and is an accurate test of performance. That parallel Twin engine is actually pretty okay. Hi All, I've got a 52 plate mondeo with a duratec 2. It may also develop an air leak and allow unmetered air into the manifold, causing an erratic idle and a sucking sound. Unstable RPM 2. DCT erratic shifting into 6th while in S mode. Fixing must be avoided. You can never tell. If the idle speed is wrong, remove the air cleaner cover, read adjust it. Everything has to be on-spec for proper performance. This condition can be. However, that early version allows some small ignition advance from ~800 rpm. Will surge RPM's when in traffic and slowing down. MG MGF Technical - Tiresome erratic idle problem Idle around 1500, usual story: drops to 900 with a throttle 'blip' but then climbs again with the occasional foray to 2000+. I recently bought a 2014 Road king 103" high output with about 1650 miles. So I cut to 3/4 of a second and it was less of a hassle. I have it set so the idle screw isn't even touching the throttle. Run the engine at idle, low cruise (1800 to 2200 rpm) and high cruise (2500 to 3000 rpm). I agree, the type of bike makes a huge difference. RPM: It's revolutions per minute. The vehicle in question was a 3. After the fact, when I mentioned the high idle the previous owner mentioned that it had been doing that for awhile. You have to adjust the idle after the engine is properly warmed. This means that the ability to write new posts and access various member features will go away. All carburetors work under the basic principle of atmospheric pressure. My idle jumps up to 1400 and go down to 1000 and jumps around, also if I’m driving and cruising around and I take my foot of the gas the car doesn’t slow down it seems to like glide even when I down shift it seems to hold at the rpm and barely goes down any idea guys?” This is a well known problem with the SRT4. Watching the tachometer shows an idle speed around 500 to 900 RPM. For about the last three months, the engine RPM has increased 1-2k when i apply the clutch. To Reduce or Eliminate Erratic Operation in Tachometers 1. Air inleakage shows up first in the idle. Turn the idle screw clockwise a few turns until you see the throttle piston moves upward a bit. Sounds like its at about 1000rpm. Before the engine is warmed up, the engine control computer is running in open loop with predefined settings. The engine may stall again after immediately being restarted. Likewise, the idle speed motor can go bad. For example, if the idle specification is 650 rpm, then the goal may be between 590 rpm and 620 rpm. My 04BMW 1200CL has idling problem. A tachometer can be used to set it to specifications but there is no risk is just adjusting it to idle smoothly. If your motorcycle doesn't have that plug, don't attempt to install the tachometer by yourself because you risk serious injury if are not exactly sure what are you doing, both while doing that and when driving a vehicle that was modified in that way. If your ignition timing is way off or if the automatic spark advance is stuck. I have a 2002 Hyundai Elantra that is exhibiting some strange behavior at idle. Or it reads 250 RPM at idle and 3000 RPM before you hit the rev limiter, and the shift lights never come on. But idle was very erratic and surged (would idle at 1300 RPM then jump up to 3000 RPM for a few seconds then come back down to 1300 after the bike warmed up the idle got a LOT better. it idles rough and will drop below 1000 rpms then up again and feels like it's lugging as the idle drops. When motorbike is started the rpm are fluctuating between 1500 rpm and 2200 rpm 2. 7L 350 V8. He also stated that it had never been in for any kind of carb service, so they are were/are as delivered from Suzuki. It must be performed under any of the following conditions: Each time electric throttle control actuator or ECM is replaced. The lights will dim as well, but I'm guessing that's because the motor is dipping so low RPM wise. If you idle modern bikes too long, or rev them hard before riding away, you can do long-term wear and damage to bearings and. I recently bought a 2014 Road king 103" high output with about 1650 miles. Leaky petcock diaphragm will give erratic idle. Have you noticed that the idle seems to surge constantly? Does it constantly move between 800 and 1800 RPM? Does the idle stay steady at 1800 RPM?. You are not logged in. Motorcycle carburetors look very complex, but with a little theory, you can tune your bike for maximum performance. Recheck the front idle mixture after the rear setting has been set. I would recommend working on the idle to begin with. ok when i cold start the vehicle , rpm is at about 1200 which i find normal since it comes down when engine warms up. • Erratic idle. These “other” tables are for temporary conditions, like the motor is being cranked by the starter, (Cranking Fuel Table) or when the motor is colder than operating temperature, (Warm-Up Enrichment table) or when the throttle is closed and the motor is coming up to temperature (Idle RPM Table) and another one for throttle closed, the (Intake. a friend brought a basket case back to life and it's running fine except the idle is down around 800-900 RPM (and feels like it wants to stall. Additionally, over the course of about an hour, the idle RPM will increase to around 3. Had the valves checked at 17K 6 years ago. Note the vacuum readings, and any fluctuations, at each speed. If it were me, I would look into cleaning the idle control valve. Cadillac problem: Car is accelerating all on its own. If you started at 800RPM prior rev-ing up, expect it to still be at 800RPM when your foot is off the pedal. I have a 2003 Suzuki Ozark that has has had idle problems ever since I got it. At IDLE, there should not be any more than 5. The normal idle is around 1200 - 1400 RPM. IT ran fine but all of a sudden it got worse and worse. This makes them require excess choking (which wouldn't be so bad if the fast idle ramp was curved better). I have a 2002 Hyundai Elantra that is exhibiting some strange behavior at idle. Not positive, but they usually start to throw a full charge about 2000 rpm. No check engine light, but the computer did show the infamous code 32. Last change: Bike was bought not running, due to stuck floats. It seems most pronounced on the Sportster partly because it vibrates more and makes more noise (no baffles). Follow the carburetor tuning procedure to set the idle mixture and idle RPM. Although generic, the specific repair steps may vary depending on make/model. The motorcycle has semi automatic transmission, that is the gears tend to shift automatically with speed and when the pedal is pressed or lifted, it tends to shift smoothly provided I shift correctly up or down. Sometimes it will idle at 1200 for a while, but it will start to go nuts and crank it self up to 4000, and it won't come back down. It's really open and shut. I hope you note this VERY well. Others have an air adjusting screw. Check the Idle Air Mixture Control Screws; they may be turned out too far. It is not important how many RPM at this point, this is just to prepare for the next step. 3) Once the motor is warm, ride in 2nd and 3rd gear from the low RPM to high RPM. A higher idle RPM can reduce stalling and the sensation of closed throttle compression braking. Now engine has erratic idle. 2011 GSA 83,000 miles. After starting and warm up, it will gradually increase RPM on it's on. 27 @ 5800 rpm. A rich pilot setting will result in hard starting, plug fouling at low RPM’s, sputtering as the throttle is cracked opened. It did not fix it. Depending on out side temps this can take up to 30 minutes. Set the idle speed adjustment just high enough that the engine idles smoothly and isn't about to cut out. Remember, the R15 is a fuel injected motorcycle and there is no carburettor. If you are experiencing a rough idle or your RPM is running high, then there are a variety of reasons for why this could be happening. Depress the accelerator pedal to the floor and hold down. Dealer changed plugs and cleaned air filter. Unfortunately, these variables are all inter-related. idles high as usual for short time then once it drops off and would normally go into the 600 rpm idle it acts like it is. MIND BLOWN. No exceptions. He also stated that it had never been in for any kind of carb service, so they are were/are as delivered from Suzuki. I am having an issue with my RPM's and throttle being erratic. The idle speed is 1500 RPM. Started suddenly the other day. Check engine light is ON. All we can set is the idle RPM. After the engine warms up idle speed will increase and the engine may smooth out (although acceleration may have some hesitation until the engine gets real hot. So for example, if you MBT out at 35 degrees at 3k rpm, then for maximum efficieny y. You have to adjust the idle after the engine is properly warmed. PWK models are adjusted by a screw/spring approximately ¾" below the carburetor cap on the left hand side of the carburetor. Properly secure the motorcycle to a lift. The 1050 to 1100 surge is a bad problem while the bike is in motion and decelerating and is widely reported, but at idle must not be that common on the Scouts?. Carburetor synchronizing has NOTHING to do with air/fuel mixtures and how they are metered inside the carburetor. I've read about IACV saying it may cause idle problems, I've also read about cracked vacuum hoses. Talking about bike or rather power engines, it is the speed by which any engine's crankshaft rotates. We stopped at another stop light and still the bikes were idling at 1500 rpm, normal it's right at 1000 rpm? I could not for the life of me figure out what in the hell was going on with the idle rpm?. I have a 2003 Suzuki Ozark that has has had idle problems ever since I got it. Stock they tend to idle between 1,100 and 1,200 RPM. On the ride home the idle was erratic and would backfire through exhaust. These “other” tables are for temporary conditions, like the motor is being cranked by the starter, (Cranking Fuel Table) or when the motor is colder than operating temperature, (Warm-Up Enrichment table) or when the throttle is closed and the motor is coming up to temperature (Idle RPM Table) and another one for throttle closed, the (Intake. We continued home at normal back road speeds, around 40 to 60 mph, and up and down some hills but nothing like the incline of the canyon. As well, bike also idles all over the map, anything from 2700RPM to 1000RPM even untill a stall. After starting and warm up, it will gradually increase RPM on it's on. If it does, a fuel pump with more capacity may be required. It seems like no matter what the RPM does, the ignition timing should be steady when idling. Idle speeds of 1,400-1,600 RPM are known to work well. • Strong smell of gasoline when machine is at idle • Uneven running (will often slow from regular idle rpm’s and stop) 2) Lean Mixtures means the Motorcycle Carburetor is delivering too much air. My 1999 Tacoma v6 3. It may also develop an air leak and allow unmetered air into the manifold, causing an erratic idle and a sucking sound. Nothing outragous but just one time it will barely be idling high enoug to keep running and then the next time I ride will be idling a bit high. Further tuning like "Air-Fuel Ratio" or AFR can be set only with a Fuel Injection Diagnostics (FID) tool. Discussion in 'Off the Topic Forum' started by GM_DaddyMac, Nov 24, 2014. Valves in tolerance (just) last time I checked. BMW Motorrad has ascertained that the software of the BMS-E is incorrect. when i turn the engine over the engine idles high, at above 2k rpms. It seems that during shifting, the rpm stays at a high rate even though the throttle is backed off, so that puts me at shifting at anywhere from 3 to 5K rpm. It wants to rev from 1500 to 3000 rpm, then back down, over and over again, every two seconds or so. Idle will drop 200-300 rpm, then return to its normal idle speed of 1350+-. If the motorcycle is in working order, the idle level does usually not change from the standard setting, so an unusually high or low idle is a warning that something may be wrong. I agree, the type of bike makes a huge difference. It is not a fastener, it is an adjustment needle, really). Continue with test even if engine will not idle. RPM start decreasing and engine stalls in few seconds. Other than that, the readings are steady and consistent -- just wrong. it idles down and lugs. This doesn't mean your engine has to idle at 1000 RPM, however, don't expect a race engine with a radical camshaft to idle at 700 RPM. 1 Full throttle system as usually used on two-stroke engines. Unstable Idle on 528i For the past few months (which corresponds to the onset of colder weather) the idle is unstable right after the morning start. The following information is strictly for the Magneti Marelli injection system. Again, start the engine and compare how it is running at a stop to how it normally runs. Only in theory are carburetors simple devices. I have developed a very erratic idle on my grand national. Car always starts, but from a cold start, after a few miles, if I stop, idle was very rough, I sometimes had. A late opening intake gives smooth engine operation at idle and low RPM, and it ensures adequate manifold vacuum assuming the other three valve opening and closing points remain reasonable. It runs rough and idles very low and will even quit a few times. I like is forum because there is always someone with a suggestion. I can get the desired idle RPM with the lower commanded timing but the stalling was even worse. KOTH: If your bike idles fine at 1400 rpm when cold but stalls at the same rpm when warmed up, the idle circuit is too rich. When motorbike is started the rpm are fluctuating between 1500 rpm and 2200 rpm 2. This will enable you to set primary idle circuit. My 84 VT750 has developed an odd idle problem. Some bike run the idle at 1500-2000 rpm. When your foot is off the gas, the throttle plate is fully closed and a separate idle control valve admits the required amount of air to get the engine to idle at 750 rpm. बाइक रेस न ले या पिकप न ले तो क्या करे। Bike res na le ya picup na le to kaise sahi kare. ZRX1100C Unstable Idle The cause was a leaking fuel pet, causing fuel to enter carbs, thus over time, flowing into the # 3 cylinder thru opened intake valves. At idle, switch set on auto, engine runs erratically, rpm goes up and down. My truck still gets the erratic idle when coming to a stop. Additionally, over the course of about an hour, the idle RPM will increase to around 3. Next, hold engine speed steady at about 2500 rpm for 15 seconds and read the gauge. Top 10 Causes of a Rough Idle | JL Motorworks. A problem with fuel delivery, spark plug operation or metering of the air-fuel charge can cause problems at idle that may not be obvious at higher rpm ranges. Idle will drop 200-300 rpm, then return to its normal idle speed of 1350+-. Happening a few times each day. When I bought this car a couple months ago, it had a high/erratic idle. PWK models are adjusted by a screw/spring approximately ¾" below the carburetor cap on the left hand side of the carburetor. FIAT Forum Useful Links: Unstable RPM on idle (with vibrations) The unstable rpm was the only thing wrong with mine and it ended up being my headgasket. said 2005-02-28 18:47 I have been experiencing poor idle quality and misfiring at low engine speeds i. any ideas?. If you drive say 5 miles, to get it warm and then it wont idle, only then you will need to adjust the idle speed, the control is located on the carb. It seems most pronounced on the Sportster partly because it vibrates more and makes more noise (no baffles). If the idle jolts subside then the problem is the vanos. For all new purchases go to the new Sounddogs. So before you start the scoot Turn the FUEL RATIO SCREW CLOCKWISE until it stops and then turn it COUNTER CLOCKWISE 2 1/2 turns. The words idle, problem, Porsche and 944 seem to appear more times together on any forum than any other niggle to do with the car. RPM start decreasing and engine stalls in few seconds. 7L 350 V8 in the alt. By continuing to use this site, you are consenting to our use of cookies. Sometimes, when I downshift, and when shifting down to 1st gear (to stand still), the RPM shows somewhere around 2000. While idling, it revved up and down between about 1800-2800 RPMs. Any ideas? The car has not been sitting and the gas is fresh. Check your manual then increase your idle a little. from the manual Forcing adaption to take place If the read out indicates that the motorcycle is not. Unless it's a really really bad noise, no need to panic or shut it off. He got scared to bust the motor. At idle, this should be at around 800RPM. Riding down the road and pull the clutch in, bike will idle around 3000, may settle down to 2000 or so, may not. Motorcycle Checkup Guide: 2009 FZ1 sputtering/erratic rpm issue The idle has been somewhat choppy as long as I can remember, but it would always smooth out. What does that mean? This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to all 1996-newer vehicles (Dodge, Chrysler, Hyundai, Jeep, Mazda, etc. let Idle until the fan first turn on. at a rough idle, the stock can will “dither” in and out in response to the rapidly-changing manifold vacuum, constantly varying the amount of vacuum advance, which creates an unstable idle. I replaced the Idle air control valve since that has caused all my idle problems with my 88 f150. On radical engines (those with cam duration over 260 degrees at 0. Erratic / rough idle in 8P S3 - and how it was fixed Just thought I'd post this for the sake of anyone that gets these faults and decides to use the search function: I had rough idling - When pulling up to a stop, the revs wouldn't drop all the way down to ~800rpm, instead lingering around 1000rpm and then slowly rising to approx 1300rpm and. When I returned from my summer ride (9300 miles), the engine was rough running when the throttle was applied above idle. Question : I have a problem with the throttle response of my Wira Aeroback automatic. high for a few seconds and then settle to the idle rpm then the carbs are adjusted towards the lean side. Carb is an Edelbrock 1405 600cfm. My 87 wanted to stall, die, or jerk me around whenever I was not giving it gas. – Rough or erratic idle speed P0507 Kia Description The Engine Control Module (ECM) controls the engine idle speed to a specified level through the fine adjustment of the air, which is let into the intake manifold, by operating the electric throttle control actuator. Aside from improper tuning, many people have minor idle problems that are easily fixed. The RPM increases whenever the clutch is engaded. My Harley is a stump puller with gobs of torque right off idle but it red-lines at 5k. Reduce idle speed slightly (850 - 950 rpm usually works). If there is a vacuum leak the gas will be drawn into the leak and cause the engine RPM to slow or fluctuate. Crimp a 1/ 4" female spade connector on the end of the diode with the silver band. Idling is occasionally unstable (most of-ten after long journeys); the engine stalls with the clutch lever pulled and the engine RPM’s drop to idle. 9TDI when the. When my MC turned 2000 miles old, I started getting a rough idle when the RPM's would drop down to about 1000. I don't have a tachometer on the Sportster but the 2000 RPM high idle seems about right. RPM start decreasing and engine stalls in few seconds. I have a 77 KZ1000 A1 and the idle is giving me hell. It's really open and shut. Like a high pulse is bad for the heart, a high RPM rate is not good for the car engine. At the first cold start-up, the engine idle did not elevate to the normal ~1400 RPM, instead it immediately went to the warm engine idle speed of about 750 RPM. In conjunction with the idle jet there is an idle jet air screw. These things can cause erratic idling and strange running. chevy forum at Car Dealer Forums; I have an '86 GMC 1/2 ton pick-up that now has a 5. Sounds like its at about 1000rpm. After cleaning the throttle body, many owners notice a very high idle, erratic (bouncing) idle, and unpredictable power surging. Usually a lean mixture. Others have an air adjusting screw. You can get to the connector without tearing the whole bike apart, and simply unplug it, if the rpm goes up, you have a bad IAVC control. When I returned from my summer ride (9300 miles), the engine was rough running when the throttle was applied above idle. The engine must be at full operating temperature. When motorbike is started the rpm are fluctuating between 1500 rpm and 2200 rpm 2. When I returned from my summer ride (9300 miles), the engine was rough running when the throttle was applied above idle. You may also notice that your ABS light comes on. Warm idle is about 850-900 and cold idle starts at 1100, slowly dropping with temperature. a friend brought a basket case back to life and it's running fine except the idle is down around 800-900 RPM (and feels like it wants to stall. Hello All, I have a 1994 F250 XLT 4X4 Super-cab with 204,000 miles. the RPM goes up & down, sometimes 700, sometime 500 ). When starting rpms rise to 3000 then will die you can keep it running if you hold gas above 3000 idel id varey. Important to remember engines make noise. If the idle speed is wrong, remove the air cleaner cover, read adjust it. But commuting the last two days i have been getting a low RPM again, about 1k or slightly high, at about 1500 rpm. if i shut it off, then start it again. What are symptoms of vacuum leaks? • Loss of power. Tumataas talaga ang idle speed ko. Depending on out side temps this can take up to 30 minutes. OK two things, probably the same cause though. They Rev Down quite Slow,,,until they eventually fall back down on the Compromised Idle circuit. He mentioned that it was more than likely an intake leak. What a magic 2 weeks after nearly a year of hassles getting the so called experts to say they couldn't work it out. The engine is mostly stock, with the only significant power adder being a mild cam (. I set the idle switch to fast rpm the engine rpm evens out and runs at the increased rpm. After starting and warm up, it will gradually increase RPM on it's on. Question : I have a problem with the throttle response of my Wira Aeroback automatic. I think a 50 rpm tick-over at idle is not normal. Idling problems, sputtering at idle and low rpm's At some point during the month of August the Roadfly forums are going to become archive only. You may need to go back to the idle speed screw to lower the idle speed if it's now too fast. when the car is idle ( neutral) as in when stopped at a traffic light the engine weakens (you can c the rev indicator going up and down )and most of the time dies out eventually. part 46 and all the parts that connect to it from the carb to the top of the airbox. As far as your idle goes, it sounds as if your carbs need to be cleaned and properly adjusted. A downloadable repair manual is a digitally delivered book of instructions that provides step-by-step maintenance, troubleshooting and repair procedures.