| Author | Message | ||
     Airbox |
can any one tell me what I should set the TFI pots to. At the moment I have them set as TFI recommend:3,7,4,7. I am running modified stock exhaust, like a Drummer, A K&N airfilter and the snorkel into the airbox removed. The bike runs ok but surges on a constant throttle above about 4500rpm. It will accelerate to the red line in every gear but just doesn't like constant throttle. Bit confused about the 4th pot too. Closed loop or rpm ? | ||
| Briz31 |
some info: pot # 1 will fix the popping on deceleration, work on this first, before you go any farther, pot # 2 is accelerator pump, don't worry too much with this one , it seems to be ok at 7... maybe go as low as 5 but not till you get # 1 fixed...pot # 3 is main jet and it looks ok and the pot # 4 well, it enables the ecm to not learn as much and it looks like it's ok for now...do 1 thing at a time ONLY and let the bike get settled to the change for a day or so , we learned that on the 12 we were testing with the tfi.... | ||
| Briz31 |
Best you talk to: Kevin Drum.. kdfab@bellsouth.net | ||
| Briz31 |
Oh I forgot to say... Increase your 4th pot to 8:15 (clock position) This should be fine. | ||
| M1combat |
The fouth pot is for "cruise". It seems to attenuate the O2 signal AND add pulse width in the cruise mode. If it's too far from 7:00 I've heard that it can throw a code. I've only heard of this happening once, and it took a while (which leads me to believe that it caused the AFV to creep to one end of it's range. After changing #4 back to 7:00, the light went away. | ||
| Wheelsleaning |
Last I heard on here, the 4th pot sets the rpm that the green and yellow fuel turns off and the red turns on, and should be set 70% off redline (around 6000rpms) which would be 6. Every few seconds my last pot will light green sporaticaly.  This is getting confussing.  The pots go from left to right, right? 1234  | ||
| Buellman39 |
Fourth pot should be set to 7 | ||
| M1combat |
I used to think that myself... That's how the TFI works on OTHER Harleys... NOT on the Buell. Pot one... Idle/slow jet Pot two... Accelerator pump and slide speed Pot Three...Main Jet Pot Four... Cruising situation O2 sensor attenuation and pulse width adjustment. Say your Volumetric efficiency is VERY low at 2500 and VERY high at 3500... You would want a low first pot and a high second... Say your VE is average at both places... You would want less extreme... A little more number one, less number two. Say it's very efficient in the lower range, but starts to wheez a bit by the upper range... You would need to do most of your tuning with the first pot... I'm not sure how the second pot setting relates to the third pot... I just know that the second adjusts how quickly the pulse width ramps up from the pot one setting to the pot three setting. The first pot is worth 2:1 compared to the second pot (or is that the other way around? Call George...) If the bike is "hunting" during steady state throttle while cruising at say 60-90, then it seems that most have found that an increase of the fourth pot will help. I tried this myself, and it helped. It also helped with popping on deceleration, indicating that it was very lean, the fuel wasn't being burned until it got to the hot header... I adjusted number four up, and it helped a lot. The reason your fourth pot is lighting sporadically is because the EFI is attempting to adjust the AFV for no reason (or at least that's how I understand it). What's your fourth pot at? Yes, they go 1-4 left to right. One more thing... It seems that one persons setting can NOT be transferred to another bike even with the same parts. I believe the reason for this is that there seems to be a large difference in settings based on where the AFV is at. Maybe if everyone reset their AFV before each tuning step so that once tuned, the ECM would be trying to stay around 100 it would be better... I don't know that for sure though. | ||
| Norrisperformance |
Set pot 4 to 8.25 to fix you problem. No higher. The forth pot works different on the Harley's Call George @ Dobeck he will explain it to you. | ||
| Wheelsleaning |
Wow. Thats much info for just 4 little screws  | ||
| Airbox |
thanks guys. I'll try number 4 pot at 8 to 8.30 to see if that helps. I have written to Techlusion but haven't had a reply yet. Hopefully they will confirm what you are saying. Cheers. | ||
| M1combat |
Call them... You'll get good support over the phone. | ||
| Wheelsleaning |
Just reset mine to those specs too. And I haven't heard back from Dobeck either, they must be busy... | ||
| Enigma |
Went out today and am really pleased the Tfi unit is working well. Has it given me loads of extra horses, not that i've noticed! Has it given me 3rd gear tyre shredding torque, nope! But what it has done is exactly what i wanted which was to richen things up lower down. Really happy that the bike isn't hunting like it did in 1st/2nd on 1/4 throttle openings. A little more urgency in hard acceleration mode and 3rd/4th roll on. And a lot less popping on hard deceleration. All in all, never expected it to make a huge amount of difference BUT what i wanted it to do so far it has. Ran it at steady throttle at 4000/5000 and no hunting felt, Set it at G3 Y3 R3 fourth pot 8 this i'll run for awhile, as personally i would like to get a couple of hundred miles on the bike so everything settles in. Then i may dyno before fiddling, tho if all's working well and me being a lazy SOB not touch it!  12S,original Drummer, Race(KN)filter, stock ecm and de-snorked. | ||
| Rigga |
happy then enigma?....keep riding it to see how it reacts if the avf resets itself overtime,but i hoped those settings would be ok on yours....just remember if you do want to fiddle with the pots,do one at a time and write down the change and any difference it makes to the bikes performance...saves going in circles that way,a very common tfi dance that...lol | ||
| Wheelsleaning |
3,3,3,8????  . That's way off from 3,7,4,7. Mine is at 3,7,4,8 and I get a bit of stuttering from 3k to 5k rpms. Damn hard to find dynos | ||
| Enigma |
Wheels, 3,3,3,8 ISN'T a definitive setting dude, just what i'm starting out with. It's working on that fine at the mo, so i'll just see how it goes  | ||
| Wheelsleaning |
I comprestand that. Just wondering how that setting is working so well when Dobeck recommends a totally different setting...  | ||
| M1combat |
Wheels... If it stutters from 3-5 try turning #2 and #3 down one clock position. | ||
| Rigga |
dobeck reccomend 3,7,4,7 for a standard machine,if anything is changed then those settings will also change....this is important to understan,those are only ever a starting point,and arte not set on stone... enigma's bike runs a drummer race filter and snorkel removed,so not standard | ||
| Rigga |
and again as has been pointe out on here before,trying someone elses settings on your bike,even if they are running the same mods is no guarentee that it will work the same on yours...each indervidual bike needs its own settings working out....i set enigma's tfi like that because i believe the main extra fuel req is lower in the rev range,i dont think it needs as much as dobeck reccomends on pot 2 and 3,pot4 i set at 8 to try to stop the ecm pulling the extra fuel out via the o2 sensor....its just a starting point,but so far it seems he is happy with it,another uk guy is experiencing surging at 4500-5000 rpm on standard dobeck settings,ive told him to increase pot 4 to position 8-8.30 and see if that improves things | ||
| Enigma |
I think it boils down to Dobeck working on settings for totally stock bike. When ever you make any change then those settings MAY not be the best to use. As someone said, not all XB's wether 9 or 12 even with same mods may run with same numbers. As Rigga said one pot at a time, make notes and let the bike get some miles under it's belt before moving to the next. IMO tweaking the Tfi running it round the block and hoping to see big changes, isn't going to work. But if we keep pooling knowledge together (good and bad), we'll all hopefully get to gain in the end. | ||
| Enigma |
Note to self Speed up replies to postings  | ||
| Airbox |
I am that other uk guy and have tried the 3,7,4,7 settings for 100 miles and got surging at 4500 rpm ( like the brakes are being squeezed on and off), so tried the 4th pot at 8.15 as suggested by Rigga and the guys on here. Did another 100 miles today and it is still surging so I shall try 3,3,3,8 and see how that goes. I have written to Dobeck but have had no response from them, must be on holiday ( vacation!). Must say I am getting a bit pissed off with it. Spoke to a reputable dyno firm today and they had never seen a TFI box so they are as much in the dark as us but at least I could get the exhaust gas analysed and maybe set it up from there. In the meantime I shall keep tweaking | ||
| Rigga |
airbox.......i did know it was you obviously,another very reputable dyno firm in the uk used to import tfi units... TTS in towcester,very knowledgable tuning firm,you could do worse than to try them for their advise,not got a leak on the inlet side perhaps weakening things right off,or poss a faulty tfi unit? got to be a reason for your surge problem...you did connect the injectors up correctly?..it does not matter front to rear but the tfi loom is paired so that the plug off the injector goes to one side and the other paired one goes back on to the injector?? and then so on for the other cylinder.... clutching at straws here | ||
| Wheelsleaning |
Well I think I worked the smooothness into my rev range but now its back to that slow return to idle. It creeps from 2200 down to 1000 sooo sloooow. AIRBOX; I feel your pain  | ||
| Airbox |
Yes Rigga, pretty sure I wired it up right as did it a couple of times as it said in the instructions that the lights would flash then go out with the ignition on and the green would be on steady when the bike was started. Well only the green flashed on ignition and it kept flashing but stayed on when I started the bike. So I refitted it and it was just the same. As for the air leak I didn't have one before so I don't see why there should be one now. Faulty unit, I hope not. I'll try the settings you put on Enigma's. I just have a feeling that it is running too rich now!!! Where is Towcester? I'll give them a bell if I can't get any joy. Cheers Martin | ||
| Rigga |
my lights work like yours.... green flashes with ignition on,goes solid when bike running,yellow and red flash on when bike is revved.. Towcester is in northampton near silverstone race track i believe...keep us posted and ill try to see if i can think of anything else,at thosr revs though your yellow accelerator pump setting might well be inducing too much fuel to the mix,lower it down or even off to see if that improves it...or even turn all the pots to off,try it to see if surging has gone,then one by one introduce some adjustment and see how that goes | ||
| Airbox |
took it out today at 3,3,3,8 and it appears that the surging has gone. George at Dobeck advised me to turn off pot 3 but it seems ok at the settings you put on Enigma's bike. Must say I can't really notice any difference with the Tfi box as opposed to without. I'll get it on a dyno and see if I can induce a bit more urgency on acceleration. I think Rigga is right about number 2 pot being set too high and making it too rich. Anyway at least the surging seems to have gone, for now at least!! I shall post on any changes that I make or differences that I notice. | ||
| Airbox |
been on the phone to TTS at Northampton and they have put my mind at rest a bit. They have no experience of the Tfi box with the O2 analyser but gave me a bit of info. This is what I gather: number 4 pot leave at 7 or 8 as Dobeck suggest as this is the one that fools the ecm. Numbers 1,2 and 3 pots should be set as though it were a carb. So a trip to a dyno with a gas analyser will be able to set up the first three pots as though it was a carb. leave the 4th one at 7 0r 8. TTS reckon that although the O2 analyser will adjust the fuel, it does it for emissions and therefore will run on the lean side, which is basically what George at Dobeck said. So even if a Tfi box was fitted to a bog standard machine it should richen up the bike to get a better response to the throttle etc but will then fail emission tests. This makes sense to me. TTS say that if the bike is running ok at 3,3,3,8 then that is probably as far as is needed. Quite how this equates with Dobecks recommendation of 7 for the second pot I don't know but I'll get it on a dyno and see. I feel a bit happier now |
