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DFI and ECMDiscuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.
What is the S/F light in the WUD stand for? Having an issue where I have an intermittent idle surge. The map will start to spike then the S/F lamp will momentarily light up. Thinking if I knew it will help chase the issue down.
thanks
I thought it would be in his sites glossary, it is not. I thought, "gimme a minute, I'll find what it is, gotta be in there somewhere". I came up empty. All I can think is it's similar to N/V which is the engine speed to vehicle speed ratio. What s and f would be?
What is the S/F light in the WUD stand for? Having an issue where I have an intermittent idle surge. The map will start to spike then the S/F lamp will momentarily light up.
S/F = Single Fire Mode (Inj - Single Fire Mode in TP)...
Rob beat me to it. I searched and found Rbob post this. Might be helpful
Originally Posted by RBob
Double & single fire is used with batch or bank mode. These modes are when either all injectors fire together or each bank alternates in firing. I know of no 3rd gen port system that uses bank fire. With one exception all 3rd gen port systems use batch mode. The only 3rd gen that uses SFI (sequential) is the '89 TTA (with the boosted Buick 6 cylinder). As for double fire and single fire: Double fire is the normal mode of operation. The injectors fire twice per engine cycle. Which being a 4-stoke, the injectors fire once per engine revolution. Single fire has the injectors firing once per engine cycle. Which, being a 4-stroke, is once for every two engine revolutions. Single fire mode is an asset. When the injector PW gets small, the ECM will double it and operate the injectors in single fire mode. This provides smoother operation through better fuel control. The ECM code used in the TPI systems from '86 through '92 have this capability. For the 2.8 & 3.1 MPFI engines, when the injector PW gets too small the ECM will go into what is know as async mode. This is a sputtering of the injectors. And basically sucks. Note that single fire mode is useful even with stock injectors. And even with a small increase in injector flow, such as going from 16 #/hr to 18.5 #/hr, single fire mode is used quite often. RBob.
Thank you. In that case, does anyone know what if would go into single fire mode randomly on surge?
I see you are a 5.0 TPI, stock setup and injectors? Looking at your screenshot your pulse width is about 2.1 mS at idle. Look at your bin and see what parameters you have for single fire mode then share what they are set to. I run EBL Flash not P4 but I would assume there are some similarities. For reference my INJ - Single Fire Mode PW - PORT Only settings are Enter = 1205.54 uSec (1.2mS) and Exit = 1403.92 uSec (1.4mS). This is unchanged from the base file I started on. The only time I see S/F active is on decel or throttle lift for shifts and I don't experience any issues with it. I idle at about 2.5 mS at 800 RPM with 30lbs injectors on my engine.
No. No where close to stock. Are you running ford injectors? I'm running 30lb red tops. I think I have correction offsets correct. But not positive.
I run the Bosch III 30lbs red injectors. What kind of mods are you running on your 305? 30lb injectors is quite the jump from the stock 19lb'ers. Could even be oversized.
I see you are a 5.0 TPI, stock setup and injectors? Looking at your screenshot your pulse width is about 2.1 mS at idle. Look at your bin and see what parameters you have for single fire mode then share what they are set to. I run EBL Flash not P4 but I would assume there are some similarities. For reference my INJ - Single Fire Mode PW - PORT Only settings are Enter = 1205.54 uSec (1.2mS) and Exit = 1403.92 uSec (1.4mS). This is unchanged from the base file I started on. The only time I see S/F active is on decel or throttle lift for shifts and I don't experience any issues with it. I idle at about 2.5 mS at 800 RPM with 30lbs injectors on my engine.
It's set at enter 854.56 uSec and exit 1113.98 uSec.
Just curious. What is your engine spec? Ill try adjusting these as well.
thank you
I run the Bosch III 30lbs red injectors. What kind of mods are you running on your 305? 30lb injectors is quite the jump from the stock 19lb'ers. Could even be oversized.
It's no longer a 305. 358, 10.3:1 compression, afr 195 eliminators, zz409 cam, 1.6 rr. Welded and ported super ram. 1 3/4 longb tubes. 4" exhaust. T56, Dana 44. So just a couple bolt ons.....I do feel there a bit big. But I should be able to get descent I think
406 10ish:1 compression, Edelbrock Performer RPM heads, Comp XFI280 Retro Roller cam, FIRST intake, DynoDon shorties, SLP Loudmouth exhaust. You shouldn't be activating it at those values and your 2.1 mS idle. Do you ever see your mS drop down to 0.8 before it activates S/F in a datalog? Post a datalog if you have one. Will need to do a zip folder to attach it.
Uploaded the aforementioned injector info. I did find some how fuel psi was way too high. Not sure how it got there. So set that to 43. I did install a new map sensor just for good measure.
idle hunting is all but gone. Soo thanks for all the help. It is still too rich, but no where near as bad. I'm gonna run some logs tomorrow and try and hone it in more.
Ran around quite a bit today. Car is making substantially more power now with just those changes. I do have a an issue with it being very jumpy at low rpm. Like idling across parking lot in 1st. It starts to buck. Almost have to ride the clutch so it doesn't start to buck. Any one have idea that would help?
Try to get a datalog of it. I have a little bucking but not terrible at low speed. Keep in mind being a stick shift, that low speed low load scenario is just asking for that to occur. To a degree it is nature of the beast. I think you can try to tame it some with less spark advance. Seem to recall that being suggested for me years ago when I was dealing with bad bucking, but knowing what I know now my issues was more so mechanical issues at that time.
I'm having issues logging at the moment. I did smoothe the timing table out some down low, and raised idle to 7 mph limit vs 4. That seems to allow me to idle along in 1st gear with minimal bucking.
I'm having issues logging at the moment. I did smoothe the timing table out some down low, and raised idle to 7 mph limit vs 4. That seems to allow me to idle along in 1st gear with minimal bucking.
In that case, compare what is actually happening with it at 7 mph and 4 mph. Where is SA in both situations? Where are your pulse widths/AFR in both situations? Whatever the difference is, is the solution to reducing bucking while reverting that back to 4 mph.
358, 10.3:1 compression, afr 195 eliminators, zz409 cam, 1.6 rr. Welded and ported super ram. 1 3/4 longb tubes. 4" exhaust. T56, Dana 44. So just a couple bolt ons.....I do feel there a bit big. But I should be able to get descent I think 
