Negative spark advance Don’t forget these sensors pick up frequencies unheard of to the human ear. S550 knock sensor calibration seems good to be and they can run good timing. When i turn the truck off for the night and start it in the morning it feels fine, then all the sudden its like a switch is flipped and no power, and negative spark advance. When the number is negative, it means ignition retarding. Oct 21, 2015 · Knock sensor spike on light throttle causing negative spark advance Jump to Latest 19K views 39 replies 13 participants last post by Purpfox Jul 3, 2017 B Apr 10, 2011 · Premise - How to setup a spark table to begin tuning Ignition timing makes torque, and torque makes power! At very low loads at barely part throttle most engines typically need 15 degrees of timing more than MBT at WOT for that given rpm. 89 degrees. 4L phasers are locked with 5-star VCT tune. I've checked the camshaft and crankshaft timing marks and they're dead on, and I've also check both the cam and crank position sensors and they're both within spec. Jul 8, 2024 · Dive into the intricacies of spark advance and retard in automotive engines. I can't seem to figure out why all of a sudden it started doing this. That table shows 35. It pulled 3* of spark from the base timing due to what the knock sensors picked up. I have attached a tune and log file. 4L) - Spark Advance Problem - OK, I'll admit it. So what gives? Some one said that the 97's read funky advance readings in general, is this true? Spark advance is defined as the timing of ignition in an internal combustion engine, determined by the electronic spark advance system, which calculates optimal ignition timing based on driving conditions and the crank angle position of each cylinder. You shouldn't have to change your histograms, charts, gauges etc. Based on that I imagine the truck was lugging itself in a high gear. This isn't a Ford truck question. The ecu forces a max default value that is likely hard coded (im not sure what it would be). Aug 4, 2013 · At least to 115 degree's when the temp needle moves. Ford uses knock sensors to add and remove timing. With any throttle input it is pulling a ton of timing. So when looking at the Spark Advance Table I pick a certain Load Variable and RPM, then look at the intersecting cell and read the advance. Even under heavy acceleration there is hesitation. Completely normal. View Full Version : Negative spark advance at throttle tip in. If it uses the max value listed on the IAT table then its pulling at least 10* in your case. 4L - I'm having trouble with my 2009 5. Discover the secrets to optimal spark advance for better efficiency and power. I have intermittent rough idle so I was looking at it today and I found that with each rough idle the spark advance goes from 15-16 (smooth idle) to jumping between 2-28 degrees Jan 4, 2018 · Negative spark retard is advance. It adds to the current spark advance. It is required to have it advance since air and fuel mixture is unable to burn immediately. The truck will only idle. So for example, if you MBT out at 35 degrees at 3k rpm, then for maximum efficieny you should be around 50 degrees during very light throttle at 3k rpm Jan 21, 2003 · Modular V8 (4. Then there is the Spark Correction Table Jan 6, 2019 · 2009 - 2014 Ford F150 - Spark Advance trouble? 5. . Learn how timing adjustments impact performance, efficiency, and emissions in this detailed guide. It will usually be like -21* to -37*. I happened to unplug the tps and the truck is drivable. Negative Engine Torque at idle? So I tried searching for this on this forum and on google, but it mostly just kept coming up with results focused on negative spark timing at idle since that is a such a common topic. (torque mgt advance at idle is 35~38* and it makes -2~-4* timing at idle) Lastly, I changed Aug 20, 2020 · In a spark ignition internal combustion engine, the purpose of advancing the timing of the engine spark is to get past ignition delay. AI generated definition based on: Reference Module in Materials Science and Materials Engineering, 2017 Jul 1, 2014 · This problem left me stranded the other day. That is typically 15-35 degrees before TDC (top dead center) of the power stroke depending on the engine speed. I thought that spark advance was almost always positive though. Is this a custom or OTS tune? I got an HT with 1 OTS tune woot. It takes a non-zero amount of time for the computer and ignition system to actually create an arc across the plug gap and because the engine is continually rotating, the event is triggered in advance of top dead center of the crankshaft Your spark is negative because your IAT spark modifier at -32* is likely pulling a ton of timing as a result of -*F exceeding the axis limits of this table. Ignition delay occurs during the time that it takes to fully ignite the mixture with a spark plug. Why? rossp July 1st, 2014, 10:05 AM Jun 7, 2023 · I noticed my car has negative ignition angle at idle of -3. Look at the knock Advance Limit Table. Dec 13, 2024 · With classes starting frequently, there’s no need to wait to start your career path. But it is a Ford engine question and I figured one of you guys would probably know the answer. May 15, 2020 · Those negative areas also started to increase toward positive with successive test drives, as if the PCM was feeling out how much advance it could apply, or in other words, how close it could get to optimum spark. Oct 21, 2013 · 2004 - 2008 Ford F150 - Spark advance reading - Can anyone with programmers give me a spark advance reading. 8K views 1 reply 2 participants last post by lightningslow Apr 28, 2019 Getting to your question: Spark advance is the time when the plugs are triggered to spark, in degrees. Lets say it's LV8=80 and RPM= 3200. It will have 10s stock indicating that the computer can advance timing up to 10 degrees if no knock is detected. Why? By rossp in forum Gen III V8 Specific Replies: 2 Last Post: July 1st, 2014, 01:51 PM Apr 6, 2007 · Since the spark advance can move much faster than the IAC, it can provide very fine control of idle speed. Jan 4, 2022 · When the number is positive, it means ignition advancing. The graph indicates the pressure variation at high engine speeds. See full list on askmyauto. Does it mean bad news to your engine? Or is it not a cause of concern at all? When you advance the timing, it means that the plug tends to fire earlier during the compression stroke and is farther from the TDC. 6L, 5. Best power is achieved when ignition timing is set Apr 4, 2013 · Let’s start with a simple explanation of why we need spark advance and how much of it we want. The spark advance at idle should be adjusted based on the engine’s idle speed to ensure stable and smooth operation. Aug 23, 2021 · Does anybody know exactly how the spark tables work together to arrive at a final spark advance? I'm referring to an '89 TPI Bin and $6E mask. If the ignition timing is not set correctly, it can result in engine damage or poor performance. Whether you're setting up your base map, fine-tuning ignition and fuel tables, configuring idle control, or diving into advanced features like boost control, tracti Sep 7, 2015 · It seems like the spark advance goes negative (seen as much as -8 degrees) when I give it throttle. It showed around 15* spark timing before. Spark advance at idle should be between 5-20 degrees. First – When you hook up the timing light to the #1 spark plug wire and it flashes a light beam onto the timing tab, it’s showing you when the spark occurs, NOT when the ignition occurs and the explosion that starts to push the piston down the cylinder. What we have done here is create a new PID that returns 3x the spark advance in the positive direction so that when it averages the two values you get the actual spark advance in the positive. The timing is very conservative to prevent Negative Spark When having a negative spark advance while scanning what dose it means? Provided that my VE table is fine and the low octane table pretty much stock (Running SD mode)?This happened in part throttle. This definitely seems to explain the backfire (late spark, unburnt fuel leaving cylinder), but why is the spark retarding? ECT Spark Advance Correction - Add (Base): This table is used to modify spark advance based on engine coolant temperature. We want this to happen just as the Oct 9, 2015 · I noticed today I was getting negative knock, about -2ish and my spark advance was also in the negative, is this normal? I thought if knock is in the negative the spark advance should be in the plus? We would like to show you a description here but the site won’t allow us. as they all log as sensor based by default. want to kinda get a feel what their readings are at idle and when driving it mine at idle bounces Aug 28, 2020 · In a spark ignition internal combustion engine, the purpose of advancing the timing of the engine spark is to get past ignition delay. com The below figure shows the crank angle vs pressure graph for the normal spark and for the effect of spark advance. Negative spark advance at throttle tip in. I changed Speed Control Reserve, External loadect, but always negative timing at idle. 5 or more, none had negative Feb 22, 2020 · Cursing down the road spark advance is around the teens up to 34 degrees, all over but never negative spark advance. I'm trying to figure out if i'm off a tooth when I did my cam phaser on the driver side this past weekend. Jun 19, 2003 · LT1 negative spark advance Jump to Latest 3. When logging you will see this as a jagged spark advance chart, most noticeable with cams at lower idle RPM’s where the spark advance generally oscillates between its min/max allowed values as the engine lopes at idle. 9K views 8 replies 0 participants last post by Z28_Sedan Jun 20, 2003 G Mechanical ignition systems use a mechanical spark distributor to distribute a high voltage current to the correct spark plug at the correct time. This process is called "setting the base Apr 27, 2022 · A few of you may be asking what happens if ignition timing is too advanced. Sep 1, 2017 · In a spark ignition internal combustion engine, the purpose of advancing the timing of the engine spark is to get past ignition delay. Tech Tips are a great way to boost your tuning knowledge in 5 minutes or less. In order to set an initial timing advance or timing retard for an engine, the engine is allowed to idle and the distributor is adjusted to achieve the best ignition timing for the engine at idle speed. I tried to find any vacuum leak, but no leak at all. If you have negative timing at idle, it is because the computer is trying to lower the RPM. Engine RPM The engine speed is measured in RPM (revolutions per minute). I have a '94 T-Bird with the 4. 6 L V-8. There is some Mar 15, 2025 · Learn everything about ignition timing, spark advance, and how they impact engine performance. If I ease Welcome to our Tuning How-To Guides – your comprehensive resource for mastering the TunerStudio software with our AMP Universal & Plug & Play ECUs. Jun 11, 2023 · At idle, the spark advance should typically be between 10-15 degrees. Best power is achieved when ignition timing is set I have a 1997 3. On a car with an ETB (electronic throttle body) the throttle will not close immediately after removing your foot from the pedal. Spark advance is essential in optimizing the fuel economy, performance, and emissions of an engine. I noticed that I never have positive advance, its always negative. It will stay the same or OPEN MORE during engine deceleration to reduce throttle closure mixture spike to rich. 8 Camaro, and was looking through some of my logs. Is that a tuning or mechanical problem? Any suggestions. Here are some causes that may or may not apply to you, but are general causes depending on the type of TB being used. May 23, 2021 · The negative spark advance is a result of the +3 KR. 75 degrees, while all the other cars I've seen on this forum have positive values at idle Is this normal or not? Here's my car for reference (sorry for the shitty picture) Other cars I've seen have +4. Apr 20, 2019 · Negative Spark advance at idle Tech Jump to Latest 8. I understand the ECM calculates engine torque from things like the VVE, MAF, injector PW, and max torque spark timing. Fluctuations in idle speed can affect the timing of the spark advance, leading to issues such as rough idle or engine kickback. It has developed a horrible stumble whenever I mash the pedal suddenly. Nov 22, 2015 · What I'm seeing is that at idle my spark advance seems to be bouncing around a lot, and even going negative sometimes. Bad ignition timing is a sign that something is wrong with the pistons or valves inside the engine. I am not familiar with a pro tune using the cobb AP as you say. Be nice during colder weather as well. Idle Tuning. Check out our Tech Tip from Bob, where he explains a common question about spark advance. Don't push the car hard or WOT till after full warm up. I got my efi live scan tool hooked up and I noticed the timing going to -20 at throttle tip in. ld lgruaaap 52wlx wxat 4zu f7px jbkd n2 k8mq w0iyu