Lex/560s wont go rich even with lots of fuelpressure and safc tweaks

[WillWorkFoBoost]

Okay so I searched a good bit for a writeup on how to tune the lex/550s mod well but havent found it again, so decided i must post. Put in lex afm and denso 560s from evo 9 last night. starts well and idles mint. runs and drives just like it should, o2 is cycling like it should. Set fuel press at 25lbs. Im only running about 10 lbs of boost and when I boost at first it was around 14 afr which was as I expected with no tune, unsafely lean. added some fuel up top on high throttle corrections, same. added some fuel press.... same. end result im at about 35lbs fuel press, +20% with safc past 2800 all the way to redline, and its going to 12 to 13 afr on boost. I want it 10 obviously... stock pistons.

have 560s, walbro 255, jtube drilled out, lex afm, afpr, safc2, and aem uego to monitor.

Other mods are, ffim, T04e, 38mm wg, 3inch all the way back etc.

Wondering what im doing wrong. any input, constructive criticism would be great. Sucks I saw a really thorough writeup on this but cant find it. but Either way its weird that im adding so much fuel and its hardly changing anything.

 

[Turbo Habanero]

why does it have to be around 10 for stock pistons i thought 11.5 was a all around safe number

 

[WillWorkFoBoost]

11.5 is a pretty agressive tune for stock pistons. as far as i know a forged piston tune is 12 12.5

 

[shipkiller]

11.2~11.5 is fine for stock piston, the 7m isn't a weakling (not trying to start a JZ war here!) as you all think it is, however it doesn't leave much room for safety margins!

 

[WillWorkFoBoost]

Ok, however what I was wondering is, what are people running for a base fuel pressure, and how much are you having to add via safc. It just seems like 35psi fp and 20-25% fuel correction just to get it to 11 or 12 is not right. Also Im only getting 12lbs of boost before fuelcut, with lex afm housing. I do have a bigger turbo but I wouldnt think that the difference in cfm would make that much of a difference in airmass. Also, if the safc changes the afm signal pre ecu, then wouldnt fuelcut be lower the more you add fuel therefore bumping up what the ecu sees for an airmass? fuelcut is around 1600htz normally but im having to add +25% via afc and my fuelcut is 11-12 lbs.

 

[SideWinderGX]

What kind of turbo do you have? It might be enough of a difference.

Also how are you measuring fuel pressure? Should be around 35-40 stock anyways. Do a quick search for what it should be and check it out.

 

[92ma71]

How much bigger is your turbo? What turbo is it? What are your other mods? Im running a ct at 16PSI with lex afm/ 560cc inj. Stock pump, no FPR. Full turbo back 3 inch exhaust. 93 Octane. No tune and I run rich as hell. I havent hit fuel cut yet.

 

[shipkiller]

hitting fuel cut on a perfectly healty engine/system with 550cc and maf lex @~16psi is still safe as you are in the 10:1

 

[WillWorkFoBoost]

I had heard that with lex afm and 550s you want to lower the fuel press to around 25-27 so i started there. stock per tsrm is 30 i believe. when I did this it ran and idled mint, o2 did its corrections cruising, but on boost wouldnt go rich, therefore i upped fuel press and added fuel, Im just wondering why ive had to add so much fp and safc correction. also my fuel cut is around 11, which even for this t04e is too low. its a .50 cold side .63 hotside, I believe its the same compressor wheel as in a 57t ct?
So anyway, my questions are<
What are people running for base fuel pressure with lex afm and 550/560 injectors?(with an afpr)

If the safc converts the Karmann signal from the afm to the ecu, making the ecu think its getting a higher Karmann reading in order to increase fueling, then am I right in thinking that because Ive added 25+% in some spots, Ive lowered my fuelcut ?

 

[nacho8705]

Running lex afm with 560's here, also Wablro 255 in-tank, Aeromotive AFPR. No piggyback. Mine idles and cruises just like stock, under boost im right around 11:1 afr.

You need to tune for VF first. I think I am at 38psi fuel, whatever stock is supposed to be. Get the Fuel pressure around that number, then monitor VF voltage with a DMM. adjust the AFM screw untill you can get the VF voltage around the 2.5v mark. You can also play with FP a little too.

This is what I did, I have never hit FCO even at 18psi on my 57 trim. The important thing is to work with the TCCS, not against it.

Hope this helps.

 

[WillWorkFoBoost]

I fixed the fuelcut issue, removed all safc corrections, re adapted it, got it boosting 16 or so lbs, goes plenty rich at 35psi fp, just taking a bit too long to go rich, also got tps code, so im assuming thats why it hesitates to go into closed loop. so Im on the right track now, so do you mean monitor vf voltage at idle? Go into a little more depth about monitoring the vf. ive read about this a while ago and Ive been searching a bunch but have not found much. i know you want to get it to around 2.5v. is this at idle? if not then how do you monitor it on the fly?also I thought 35 was higher than you want with 550s; the fuel pressure basically just affects closed loop so i can pull fp til I get a bit leaner on boost correct?(wideband only goes to 10.0 and it pegs so is probably more rich than that) Sorry for many questions.
Thanks

 

[nacho8705]

The Lex afm and 560's are a matched upgrade. 25% more air, 25% more fuel. Once you get the idle VF ok, the rest of it just kinda falls in place (for me at least). If you are getting super rich under boost, first make sure you dont have any boost leaks. Then try back the AFM screw out a little bit. This will let more unmetered air in and lean you out a little. Fuel Pressure affects the entire range, not just closed loop.

VF is basically a representation of how hard the car is working to get the target afr (14.7)
look here: http://www.supramania.com/forums/showthread.php?119181-VF-signal&p=1534125&viewfull=1#post1534125

Also after you tweak with it a little bit, I have found that it is best to pull the EFI fuse so that the TCCS can re-learn.

 

[3p141592654]

The ECU will take 3 seconds to go open loop when the load exceeds a value that is a function of rpm (44% at 3600 to 0% at 7600 rpm). That may be the delay you are referring to.

There are some conditions where the open loop delay is eliminated such as:
coolant < 45C, rpm > 6000, throttle open > 79%, throttle open > 46% and rpm < 2000, fuel enrichment > 50% (depends on load and rpm), engine stressed (THW > 95C and knock sensed)


If the car is running closed loop, then adding fuel using the SAFC will not work, as the ECU will knock it back to retain stoich conditions. This is indicated by the Vf signal mentioned above deviating from 2.5V. The trim value varies with rpm, so don't just check at idle for example.

 

[WillWorkFoBoost]

Ok so from what I gather, a major trigger of going rich on boost is throttle position. my tps is currently effed up and matted will only show 68%. I think the issue is in my wiring as ive tried a couple used tps's and a new one. So it sounds like the biggest thing affecting my tune currently is tps. runs well cruising and if you just hold it in it will eventually go rich, just tends to chill around 14 for a bit too long for my liking before dumping fuel, probably when it senses knock. so It seems like if your car is functioning well, and if you monitor and work towards a good vf signal, an safc is almost unnecessary. thanks much for the Info.

 

[Nick M]

I had heard that with lex afm and 550s you want to lower the fuel press to around 25-27

Where did you read that? It wasn't from the Sonic page where the mod was discovered.

which even for this t04e is too low. its a .50 cold side .63 hotside, I believe its the same compressor wheel as in a 57t ct?

A stock Lex housing will run far more than that with out trimming the signal. I have skimmed ahead to see that you removed the SAFC and now it works right.

So anyway, my questions are What are people running for base fuel pressure with lex afm and 550/560 injectors

Just more info for you. I have the stock Toyota regulator and no tuning device, save for the screw which does the same as an SAFC.

If the safc converts the Karmann signal from the afm to the ecu, making the ecu think its getting a higher Karmann reading in order to increase fueling, then am I right in thinking that because Ive added 25+% in some spots, Ive lowered my fuelcut ?

If I am reading what you wrote correctly, then you lowered fuel cut. You increasd the signal to the ECU making it think more air is going into the engine than really is.

 

[WillWorkFoBoost]

yeah, and in turn you could squeeze a bit higher fuelcut out of the system by going negative with safc corrections, and adjusting fuel pressure and afm screw appropriately. it modifies the karmann signal pre ecu.I didnt remove safc if you had read through the posts I was having an issue with it not wanting to go rich, which is probably my tps. Ive basically figured this out. Was just looking for a lil info on peoples setups with lex/550s. thanks.

 

[Nick M]

Toyota lists the TPS as a minor correction factor in the manual. Not a major factor. Maybe 3P can show just how much. Other manufacturers put more emphasis on it, because it relays the drivers intentions.

 

[WillWorkFoBoost]

So update. Maf finally shit the bed. maybe that was the issue. It had no codes or symptoms and then I went to start it the other day and 3htz on the safc unchanging, maf code and 10.0 afrs at idle. =) having a questionable maf in the past few weeks probably wasnt helping the tune.

 

[GrimJack]

Another thing to add to the pot. Your TPS only reading 70% is likely fine - I suspect that your SAFC is displaying throttle percentage based on a 5v scale, and all the Toyota TPS's I've checked are WOT at ~3.8v, not 5v.

 

[3p141592654]

That is true. The usable dynamic range of the TPS, subtracting the values at idle and WOT is about 3V.