Stalling at idle - HELP!!
 

Update!!!



Okay so giant horrible news.

A leakdown/compression test was performed. Discovered that it’s leaking in cylinder 3 causing misfires.
Compression test failed in cylinder 2 and 3.

Engine is apart now at Toyota. Not sure what the cause is but the issue is cylinder 3 is not sealing when it’s at the top of its motion and it’s leaking fluid is what I’m told.

Car has 131k miles on it and along with some other maintenance related things (timing chain:tensioner:guides) the car needs a new block I’m told.

Any chance I can get Toyota to fork up some of the bill? Am I SOL?

Looking like $6500 in repairs on a motor that runs and seemingly runs fine after idle. Able to drive it for seemingly years as I’ve been trying to track down my issue for these few years.

Any options? Suggestions?

Thanks!

(Below is my initial issue)


__________________________________________________ _


The problem:

Car runs extremely rich at idle. ��
-30% LTFT
But when under load it seems to even out the trims and run fine.

Mods:

Ptuning header (equal length)
JDL frontpipe (cat+silencer)
Ptuning catback
Grams throttle body (new - hoping this would fix the issue)
K&N Drop in air filter
Running on e85 for 6 years now pretty much exclusively.


Car sits at 600 rpm dips below it at idle then tries to rev up sometimes to like 2.5k rpm. Rinse repeat about 6 times. Sometimes it’ll just stall and sometimes it’ll stall after 2-3 times after it revs itself up and down. Sometimes when accelerating the car has a weird pop noise like plasticy sounding pop and the engine just doesn’t want to move. Often idle dips when pressing the gas pedal before it actually accelerates almost have to pre-rev it just to get the car moving from idle.

I’ve cleaned my stock throttle body, didn’t work so I replaced it with the Grams throttle body, Ran fuel injector cleaner and replaced the fuel solenoid.

Spark plugs were changed at 80k miles and the car now has 130k and I’ve changed them again.

(UPDATED replaced PARTS LIST)

New Sparks OEM
New coil packs Delicious tuning
New throttle body Gramms
New Perrin air intake tube
New air filter K&N
New MAF OEM
New MAP OEM
New O2 sensor OEM
Cut Snorkel ��
New PCV valve
New Oil catch can
New Battery
New Injectors OEM
New OEM Evap solenoid
New DW300C Fuel pump

Unsure what to do from here.

My tuner (Delicious tuning) is out of ideas and has given up helping.

Would removing the header and factory tuning it and then taking it Toyota be my only solution?


Any help is appreciated!

Have you checked/cleaned/replaced your air filter?

Absolutely. Every oil change.

No check engine light? I wonder if your e85 use has degraded the fuel pump. This also sounds like what happened when my fuel pressure regular went bad at 60k miles.

Have you tried disconnecting the negative battery terminal for a spell .... which will allow the ECU relearn some stuff?

New battery

And

New grams throttle body, so disconnected battery then also.


Zero check engine lights.

I would get rid of that aftermarket O2 sensor and install the OEM sensor to start. ALWAYS use OEM sensors in these cars from a reputable source. Unfortunately, dealers are the best source for these sensors.

Also, not only are aftermarket sensors NOT reliable, which is reason enough to not use them, now you have to watch out for counterfeit "OEM" parts.

I'll go replace it today.

Next will be Mass Air Flow Sensor (OEM)

check a few things on a scantool, or something that will display engine parameters.

Look at what the ECU is requesting for IAC steps (or however this car plays with idle speeds), and see where its actually idling at

look at TPS both requested and actual

look at cam timing on all 4 cams

look at ignition timing, fuel pressure, anything else related to this. If anything looks off, or isn't what is being requested, start looking there.

The worst thing you can do is to just start tossing parts at it. You may get lucky, or you might replace 6 good parts before you get it

Be logical and reason your way thru it

I have the ECUtek Bluetooth so it connects to my phone and can see all different logs for what the cars doing but I’m not sure what “normal” is.

Also replacing 6 good parts isn’t a problem since I’m at like 115k miles and some of these parts have to be replaced anyways.

There are a couple of people here that know what normal looks like and will look at your logs if you post them, and even give you advice on what to replace.

Did you ever get that O2 sensor replaced?

Replaced the MAF with an OEM.

Same issues.

I’m running -30% LTFT at idle.
Car stalls out nearly every red light now it’s horrible.

Updated main post with parts list replaced.

Bump

No logs, no help

Does this seem exclusive to hot starts, or does it affect cold starting, too?
The scaling on the wideband could be goofy, but Delicious should be able to figure that out..

I have several logs where a tuner attempted to fix the issue but was unsuccessful.
https://datazap.me/u/celigts

Here’s a log of idle so you don’t have to sift through the logs/tests.
https://datazap.me/u/celigts/1351-tune?log=0&data=16

Delicious hasn’t figured it out and called it quits. Never fixed their logs for mapping and I’m tired of them having poor service.

Problem isn’t exclusive to cold starts but does seem to be worse in hot weather. Likes to stall more.

Could be totally unrelated, but there is a intake air temperature compensation fueling map I had to raise to like 150 across the board to let my car to idle correctly on hot starts and in general. My car was stalling on clutch in and generally any time the car wasn't dead cold.


This does not sound related, but it could be another contributor.

The logs in your datazap account are a pain to watch, should be renominated in Atrocious Tuning

I’m confused…

Whatcha mean ��

I had a guy attempt to fix the rich/idle issue so there’s logs that are mainly for testing purposes.

Ok sorry i ve miss understood, that you were tuned by delicious

if someone is scaling your fueling on your tune and those are logs of that, he s not doing a great good

I've experienced similar symptoms when some kind of harness or connector issues related the MAF sensor. After I arranged the harness near the MAF connector it came back normal usually. You should make sure MAF scaling was done with normal connection state.

And care must be taken when scaling below 1.21V range of MAF sensor.

Thinking it’s a bad harness?

My harness looks intact but unsure how to check exactly.

It’s reading fine from my understanding.

New MAF put it and no change.

-30 means its subtracting as much fuel as it can(or close to it anyway) this is a huge red flag and one of the type of things I was talking about. This means its super rich when in closed loop.

you can monitor your short term fuel trim while you do various things such as idle, stead 2500 rpm in gear, gentle cruise at 2500, decel in gear, accell in gear etc to further isolate where the problem is happening.

Rich is both trickier to find and easier to find than lean as only a few mechanical things can cause it. Fuel pump, fuel pressure regulator, kinked return line(tho I suspect this is a returnless system), leaking injector(s), etc. Yes a bad MAF and/or primary O2 sensor can cause this too, as can a bad PCM, but these are where to start

I tuned to stock and it’s running -10% LTFT at idle however I still have my PTuning header on the car and it’s throwing 3 codes.

P0137
P2096
P219A

I’m told these are from the catless header and should be the issue.

Getting tuned in person on Monday by Counterspace Garage so we’ll see.

Was thinking leaky injectors but I replaced the port injectors. The DI injectors we’re going to be done but I was told it more than likely is a waste of time. 🤔

Any updates?

Okay so giant horrible news.

A leakdown/compression test was performed. Discovered that it’s leaking in cylinder 3 causing misfires.
Compression test failed in cylinder 2 and 3.

Engine is apart now at Toyota. Not sure what the cause is but the issue is cylinder 3 is not sealing when it’s at the top of its motion and it’s leaking fluid is what I’m told.

Car has 131k miles on it and along with some other maintenance related things (timing chain:tensioner:guides) the car needs a new block I’m told.

Any chance I can get Toyota to fork up some of the bill? Am I SOL?

Looking like $6500 in repairs on a motor that runs and seemingly runs fine after idle. Able to drive it for seemingly years as I’ve been trying to track down my issue for these few years.

Any options? Suggestions?

Thanks!