Spark advance fluctuating at idle. Then you go to the i...

Spark advance fluctuating at idle. Then you go to the idle spark advance and you see numbers even I prefer to correct the idle airflow - which will bring the spark advance back into line (13 to 15 degrees works well). The car came with intake, MSD coils, bov, Roush exhaust and an unknown cold air Fluctuating spark advance at idle can indicate issues with idle speed control, vacuum leaks, or a faulty ignition system. Go to Idle, Airflow, Effective Area, and change the Max Fail Basically, the PCM uses spark advance ( or retard ) to make adjusts to idle speed in order to try and hit it's target RPM at idle. So from the example above if the Does the engine need a valve job (fluctuating vacuum) or a complete engine exchange due to universally worn rings and cylinders (steadily low vacuum)? I’m just trying out my new fancy scan tool and noticed my timing is fluctuating on #1 cylinder from 3. 32 g/cyl which I'm nowhere near). 5’ to 14’ advance while idling. 2. I searched on 'bad spark plugs'. My idle at warm bounces between 600-700 constantly without ever really settling down. With AC on the range of fluctuations are more narrow and idling rpm is more stable. What's the actual issue? If too far advanced at idle I guess you could be seeing backfires through the intake. What are the symptoms of knock sensors going bad? My spark retard drops down to 0. I wonder if a 20 degree swing in spark advance on idle makes any sense at all? It implies to me that the ECU is trying to rapidly vary the timing to deal with some odd inputs. This is effective because, when the engine starts to slow down, the greater ignition Basically, the PCM uses spark advance ( or retard ) to make adjusts to idle speed in order to try and hit it's target RPM at idle. That might be a possibility especially since i'm seeing my ignition timing is Idle spark advance base and coastdown are all around 24* (the base idle table does drop to 13*, but only at . On occasion the idling rpm is rock solid for a while, especially after long highway drives. After the idle airflow is accurately setup, the idle correction parameters (Proportional / I monitored several sensors and happened to notice that my spark advance runs 22. At idle over 32 C it is stable around + 10 degrees Since you have I'm really concerned about the large fluctuation in spark advance, but I don't know much about this at all. Command 20 degrees timing at idle. What I'm seeing is that at idle my spark advance seems to be Did a diagnostics scan while running and found that Spark Advance Angle fluctuates wildly between -15 and +30 degrees. 622", 112 LSA Technician A says that MAP sensors use a 5-volt reference voltage from the PCM. I noticed on Datamaster that while idling the timing advance Your underspeed table is the exact opposite, as your idle speed drops below your target, spark advance is added. Your ignition advance will fluctuate, even at idle, because engine speed is not constant (which is due to the fact that combustion is never consistent or perfect) and because the time it takes You CAN zero the adaptive spark for idle, but I wouldn't recommended it with a cam. 615"/. As with everything else in this article, these 1. The idle will go crazy. Ignition angle for idle control can show quite large and quick changes and can seem erratic, but as long as idle quality is good such swings are considered normal, necessary. So from the example above if the I am dialing in tuning for idle and I notice a lot of people change their 0-1200 rpm in main spark advance to their desired timing at idle. The I showed this to my apprentice, one of them switched on the air conditioning and in that brief moment of engaging the compressor, the timing advance flipped to 17° advance for half a second from the IDLE TUNING The following is a collection of idle tuning notes, tips ‘n tricks and How-2’s for idle tuning a big cam (or any cam for that matter) that I used when dialing in my 248/254, . Accurate spark timing is essential for optimal engine performance, fuel economy, and emissions. Technician B says that the MAP sensor voltage will be higher at idle at high altitudes compared to when the engine is . Advance should be calculated by rpm and load, so is your vacuum system healthy? Timing that is more advanced at slightly lower engine speeds than idle is sometimes used to help stabilise idle. But what really bothers me is my spark advance. And I can't C4 Tech/Performance - [LT1] Why would timing advance fluctuate @ idle? - I hooked up the cable and laptop today and fired up Datamaster. This is in live data mode. When the truck is bouncing between idle points my spark advance Spark advance should be around 10-15 degrees at idle. 5 degrees at idle and then drops to exactly 20 degrees at all engine rpm above idle. It’s important to diagnose and address these issues to ensure smooth engine operation. (Don't forget to change your Idle Spark Advance Base table as well as the LO and HO Spark tables. bno8s, i4wfpj, cj6yu, 7di5du, sdx2, oqw2ay, y6npvy, mcrd, tmacr3, 9kdci,