General Any throttle goes lean at idle

[darknezz7]

Maybe I just have no idea what I am doing tuning wise but here is my issue...

This is on ECU+ and I know no one uses it or knows much about it but it seems a pretty general tuning system. So please give advice even if not related to ecu+.

With the stock maf when I push the throttle even slightly it leans out and stumbles, idles good at 900rpm 14.7afr though. Looking at a capture the maf output is way low compared to the input when I press the throttle.

If I check maf bypass mode (this sends the stock maf signal through the ecu+ to the cars ecu with no alteration) the car revs good but idles rich around 12, most likely because large injectors, capture shows maf input output the same. Obviously I cant tune it like this though.

The GM maf is the same thing but it idles better and ofc I cant bypass it. I had the analog output 0 and 1 voltages set to simulate for the iat and baro. Lets focus on the stock maf sensor for now though.

I'm just not sure what I need to do here, keep raising the fuel map till it does not lean out?

I feel this is directly related to some setting or fuel map I need todo in ecu+. I just do not know what todo... The car sounds pretty good though .

I have the injectors scaling set to 780 (highest it will go), but they are FIC 850cc installed.


Any advice appreciated.

 

[darknezz7]

In bypass mode I guess it still acts weird, at 1500 rpm it bounces back n fourth, but revs ok otherwise and does not lean out, idles rich.

Not bypassed I tried turning the fuel maps up to +50 and it did seem to help, but still gets lean around 2000 rpm. Its like I cannot make it add enough fuel. Again the mas output is considerably LOWER than the input, like I did not see it go over 100hz while input was near 200hz. I know this is they key, I just dont see what todo...

This is all just revving it, still have not even driven....

So frustrating

Some info for you guys:

FIC 850cc
cheap adj fpr, but seems to be working
S90 70mm throttle body with no idle control valve, car idles good though and not bad from a cold start, 30 to 60 seconds of holding throttle, starts right up and idles without touching.
Justin 20g

Walbro 255 rewired

A lot more too, but the top 4 things are the biggest changes and ofc this ecu+. I wonder if had link this would not be happening...

 

[98MitzuGST]

boost leak test to make sure air isnt getting in after the maf. or could just be a bad maf, could try getting one you know is good and swapping them to see if there is a change

 

[98MitzuGST]

on aem ems this sometimes happens when my tps sensor acts funny also, make sure you have that set to the correct voltages

 

[darknezz7]

Its all new stuff and everything tight. Besides the gm maf is right before the throttle body and it acts the same way. The ecu+ is a translator too, but again the input doesnt match the output.

Heres the setup except using a ported stock exhuast manifold cause that tubular crap leaked.

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[darknezz7]

The tps reads 0% to 100% and seems linear.

 

[darknezz7]

Something interesting...

If I set the injector scaling to 450cc (stock) it behaves much better, mas input/output look closer and adjusting the fuel maps actually affects things like idle and reving through rpms I can make it not lean out.

So this seems progress BUT WHY would the inejctor scaling affect it like this when there is (supposed to be, they say they are) FIC 850cc

One thing still though with very light throttle at 1500 rpm the idle bounces up and down, if I push more it seems ok but it is SUPER touchy and responsive. Lol like thats a bad thing, but its making it hard to tell.

 

[Dsmkauai]

Have you even done a boost leak test? Just cuz it's all new stuff and you think it's all tight doesn't mean there's no leak. Always I repeat always do a blt when messing with the intake or turbo. Shouldn't even be a question and should be regular maintenance. Do atleast 5psi above your goal boost level. I'm not saying it's your problem but you need to rule it out. Plus it's so simple to do and just needs to be done with a turbo car. Also my good friend used to run ecu+ with fic 850's I'll txt him and if he has any help for ya. See if I can get him to chime in on the thread.

 

[darknezz7]

Yea ok Ill do a blt for the hell of it. I have an adapter I made for a audi 1.8t awhile back.

It really seems like a software issue though

 

[Dsmkauai]

Is your bov recirc tube really just taped on? If so I don't see how that will work!

 

[darknezz7]

Its always worked fine before and that is not the issue here. Plus it squeezes pretty tightly in the other tubes and the tape just holds it there, its not leaking.

I'LL SAY AGAIN

This does the same thing with the GM maf which is AFTER the BOV and right before the throttle body so theres really nowhere for it to leak.
the idea is to ditch the stock mas so the BOV can vent.

But I know the stock mas works and it just for testing right now.


I guess I'll just have to keep messing with everything til I figure it out myself.

Thanks for the ideas though and yes if your friend that ran this setup has any ideas thanks.

 

[darknezz7]

Current settings:

Using GM maf.

Injector scaling: Stock 550cc (really the car had 450cc stock)
Actual size 450cc

Even though FIC 850cc are installed the car acts much better this way, if I set it to actual size 780cc (highest it will go) it leans out on any throttle and adjusting fuel maps do not help.



**I set the TPS to 7% and it made this problem go away, now the car revs smoothly and quickly while being able to adjust fuel maps.**

Faulty TPS maybe? What else would cause this? This is not the first time I've seen people have to do this, but what causes it? I know link can zero the tps, I do not see any adjustments on this ECU+.

Should I go ahead and continue to tune the afr's at this point and drive?

Heres a video this was after adjusting the fuel maps and the TPS is at 7%
How does stuff look? (ignore the coolant and air temp as I dont have those hooked at atm to the ecu+)

I want to go drive this beast

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[10's or bust]

The coolant temperature is very important and should be hooked as the ecu automatically assumes it's negative 20 which would be one of the main issues you have tuning and very well could be the main reason it wants to go lean no matter the throttle above idle I's at least hook up the coolant temperature if the Intake Air Temperature is not

 

[98MitzuGST]

yea when i did a head job on my old car i forgot to hook up the coolant temp sensor and it would barley idle or anything, id say that's your problem

 

[darknezz7]

Guys... I am well aware of the ECT sensor what it does and that it needs to be hooked up.

It has been plugged in just did not have the wire to log to ecu+ at the time. It is hooked up now and reading IAT and ECT

Now the stupid brakes will not bleed grrr

 

[10's or bust]

Dsm's gotta love em or hate em until whooshhhhhh and then you realize why you loved boost in the first place. Sigh

 

[darknezz7]

So I did the 2g tps adjustment procedure which put the tps at about 10.5% and adjusted the idle stop screw, put in the air screw (remember this is a 70mm "s90 knockoff" TB), low and behold its running much better.

Current settings, fully warmed up, kinda runs like crap til 200*f coolant temp:

injector scaling, stock at 450, actual at 450. 850cc installed.
mas lower clamp at 28hz
idle 900-950
afr 14-14.8
adjusted fuel maps to around 11 afr through revving rpms
ignition timing 5*-8* at idle
-18.5 psi vacuum
adj fpr set to 45psi vac hose off

HAVE NOT touched timing maps... Will play with next, remember I have no idea what I'm doing on tuning.


NOW WTF why wont the brakes bleed... The pedal is soft and takes a few times to pump up then is fine for about 15 secs then soft, done all four starting from furthest using a tube on the valve into a bottle of brake fluid so air cant get back in... WTF it was fine 4 months ago... I've only bled like 1000 brakes so I guess the master cyl took a crap...

I don't exactly want to street drive it with just the ebrake... I took it around the yard though, can tell its got a lot of power and the 6 puck ceramic clutch is kinda harsh hope it breaks in.

Dsm's gotta love em or hate em until whooshhhhhh and then you realize why you loved boost in the first place. Sigh

Too true, this is not even my car its a good friends but its a project between us and I plan to take it to the track one day. Boost is awesome though, I have a engine swap todo on my bmw e30 then that will be boosted.

 

[10's or bust]

I kno rite

 

[98MitzuGST]

+1 to master cylinder seals, can either rebuild or replace. its not to hard to replace though, good time to upgrade to a 3g master tho

 

[darknezz7]

Yea well we just bought a new brake reservoir, lid and bracket for it, I didnt find out about the 3g master til later. Is that the only advantage that the reservoir is attached? Does look better...

I've never tried replacing the seals in a master, have in calipers though.

 

[darknezz7]

Brakes are good now.

Stumble under boost.

Then did a boost leak test and found it leaking really bad at the throttle body shaft seals mostly on the tps side... wtf brand new crap off s90 TB...