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bouncing afr's on aem fic 8


mellonman

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i have had this happen since i had the aem fic 8 fitted

 

when off boost and cruising or when off throttle completly the mixture goes mad off throttle it goes lean 18-1 (normal when rolling)

but the jumps rich 10-1 then back to 18-1 and will carry on doing this even under braking it does it and i can feel the car pull forward when richin out?

what would cause this?

 

i have 650 injectors

 

i do live with it now as dont use the car much but really want it sorted

anyone know anything about this ?

Edited by mellonman (see edit history)
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Stock ECU still needs to see O2 sensor, modified or unmodified. Don't trust garage wiring. Check under carpet for O2 pin on FIC and see if it's got anything wired in.

 

Is AEM wideband wired for logging only or did you get them to build a map?

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having trouble getting hold of them.

 

but now i have all the soft ware and have be doing my research and found that i may need to fit a 2k ohm resistor in the crank and cam signals due to toyota using a magnetic sensor and it picks up interferance.

 

so route 1 fit resistors 1 at a time to see if that has affect

if not better

will go up the road and see what the fic is doing at that state when it does it and seee if i can compensate on the map

 

i have copied the map so if it goes tits up then i can just up load it again, but not too bothered as its all off load stuff and and will only be doing fuel map and keeping a eye on the afr guage

 

this is very close to being right so is just off slightly.

 

will keep this updated as this is a common fault with the fic, not the best bit of kit very basic but software wise wow what a nightmare reflash this use these drivers then use these drivers then reflash back to that

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Was toying with using FIC on my Skyline, because its supposed to deal with CAN bus on later cars, i do believe it has the ability to tweak the std lambda feedback to the ECU,(have you also looked at this?) but another drawback i found that it cant directly advance the ignition timing, so you have to start buggering around with MAP or MFA if you want to advance the timing, so i thought sod that, i would be better off with an EMU, but after a bit of research, i decided that some direct ECU re flashing software is the sensible option, but obviously mine is not a Supra.

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yeah i see that you could do a hole map from the lambda and have a even better one from the wideband but have to adjust the fuel map for the afr changes for the long term fuel trim if you just do it on the afr the stock ecu will work them out over time, but i think i will try and keep it simple at the mo.

i didnt think you could advance the timing in anyway?

i am no mapper

the car runs great wot but its just off throttle in closed loop its abit poo so i think its where stock and fic conflict i believe.

 

well we will see how it goes if i post in the wanted section for a engine it went terribly wrong.

 

i do wish i never bothered getting the bigger injectors for some hybrids that probably didnt need it should of found out more info and done flat out tests with stock injectors and clamped my boost at what i could get away with! never mind live and learn :D

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Just had a re read, are you sure that the FIC has been configured for the larger injectors correctly, as it sounds like the mad rich to lean behavior is just the result of the std ECU flicking the injector duty back and forth, in it usual effort to keep the idle and closed loop AFRs to around stoic, but as the injectors are larger its causing a much larger AFR swing than usual.

If not as i said check the std lambda fudging function.

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Are you still running the stock O2 sensor along with a wideband?

 

Agree with Ricky, sounds as though they're fighting each other.

 

I recently fitted one on an Aristo, running fine, but we just used the AEM wideband and done away with the stock O2 sensor.

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I very much doubt the injectors are set correctly as every thing else done by the garrage went wrong why not this

how would i tell?

 

sweet thanks for the responces guys will post up cal file tonight when im with my lap top,

 

i am running stock o2 and a wide band in the first decat,i used to have the wide band in place of the o2 but tuner said was best to put stock back in for when you lift off throttle with out it it dumps fuel in as in rich state from stock ecu

 

 

Up date:

fitted 2.2ohm resistors to crank and cam signal which helped a slight miss at 4000 rpm :D

i adjusted the injector responce time put that back to the standard aem setting of 486us which corrected a hot starting issue.:D

 

but

with the bouncing afr the fic does not show me that its doing anything when its doing it? :( but was very hard to do all on my own on the road but have my brother round tonight for karting so he can drive while i watch and tweak.:eyebrows:

Edited by mellonman (see edit history)
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First off YES! a stable ECU voltage is curtail, i would investigate that first, the ECU earth could have been disturbed when the FIC was fitted, and judging by your fitting garage well, i would be double checking all their wiring.

 

From what i remember the FIC has an adjustable injector lag/offset, you need to check the factory recommended lag setting for that particular injector, they can be tweaked slightly, but i wouldn't advise much,

I cant remember how the FIC deals with larger injectors, has it got a global setting or do you compensate with the duty-cycle or duration map?

 

The other point is with the Lambda tweak function, again cant remember 100% but i think it can ad or subtract to both a std lambda or the UGEO simulated narowband outputs to the ECU, which ever you use, it shouldn't make a difference if the simulated output is calibrated correctly, thats another thing to look at.

It also could be a possibility that the simulated output hasn't been adjusted and is outputting a wideband output, and if fed to the std ECU will cause big problems.

 

Personally i would double check everything, after what you said about the garage, in my experience most garage monkeys wouldn't have a clue.

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okay cleaned up the earths and got a more stable ecu voltage sitting more around 14v with small decimal changes

 

problem still there :(

 

in looking at the fuel map the no load was set to -50 when changing that did make the bounceing better.

 

how do i attach cal file it says invalid file

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hopefully this works but i think i might of seen a issue with the injector sizing as the old injectors was 440 and i have put in 650 but they have put it in the map as 1000 old and 1000 new? please see attached if you need the password to open its melonfic

im starting to get abit worried that im gonna have to ditch the hole map and i cant even map it as dont have any det monitering equipment.

thanks for all you help guys i think im gonna need it what a bodge of a install do you think i could get any money back from them?

 

anyway have now done some playing to see what the differeance would be and can work out that the -50 should be -32 to keep the injectors in line with the stock setting.

so i think i have cracked it being that the -50 is way to lean and the stock ecu is kicking in and making the car really rich to compensate thuse bouncing thats my thoughts anyway, i get my coil pack clips on tuesday so will give the car a good going over and see if that sorts it

gary2.zip

Edited by mellonman
found out more infomation (see edit history)
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The injector resize function always defaults to 1000 to 1000, and so it's not possible to see how they resized in the past for those injectors. What is the lag time on those injectors? as that is set to default, and not been changed.

 

What revs does the lean/rich condition occur? between 1200-2400? It does look like it's lean trimming excessively for deceleration under 3psi absolute because this fuel trim map set to -50%, try 0% or maybe -30% as you say to enrichen this. Not sure what the map will do below 3psi as your table stops there.

 

Run a log when this condition occurs and post the log so I can "replay".

Edited by Yakky (see edit history)
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I think the 3 psi is not a factor as it accounts for the absoute air preasure so even with engine off i get that reading pritty much would depend on where the car was in relation to sea level.

 

yeah your right it does seem to be in that rev range it does it!

 

cant move that car at the mo as i damaged the coil pack conectors checking them.

but as soon as i will let you know what i find and post up the log.

 

the injector responce time was set to 405 but i was having hot start issues and on the aem furum and there was lots of threads stating uping the injector responce time helped with poor starting this did help but i under stand now that the bouncing proble with -50 will also give me a lean cranking condition so this might be 2 birds with one stone.

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enriched the settings to a more suitable setting 0f -30 was a little better but still does it down hill or rolling, tryed loads of things i will now drop down the psi down to see what is happening lower down if it gets there on vacuum,

wish i had more time out to do it as laptop battery is so rubish couldnt even get to do a log after all my attemps

i will log first this time and try and over come after.

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contact ryan.g hes done mine well

 

yes but im having trouble contacting him.

 

 

anyway got it alot better tonight the fuel trim was quite away off so ecu was over compensating making the afr bounce it still does it slightly i also dropped the psi down to the 0 as surgested and did help please see attached log of fault.

this was before my adjustment doing down a slight hill

FIC86_15_2011 19_26_38.zip

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yes but im having trouble contacting him.

 

 

anyway got it alot better tonight the fuel trim was quite away off so ecu was over compensating making the afr bounce it still does it slightly i also dropped the psi down to the 0 as surgested and did help please see attached log of fault.

this was before my adjustment doing down a slight hill

 

 

ahh i think hes in madrid working maybe??

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