Ford Focus ST Forum banner

1 - 20 of 21 Posts

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #1
Hey guys, been chasing this issue for about 4 months now, the dealer couldn’t find anything. Car is a 2016 focus ST. Mods are full bolt on, 2867r, 4 port aux, and dyno tune. The main symptom is bad almost stalling idle, when taking off from a stop the car stumbles and hesitates in first and second gear below 4K rpm, and randomly I’ll get “hill start assist not available” even when hill start assist is turned off. Current list of things I’ve done, replaced every sensor on the engine, replace direct injectors, new plugs, new coils, did every splice on the harness, new purge valve. The main code it throws is p0172. Once the stumbling stops the car still runs like crap, any little touch of the throttle instantly sends the car into boost, also the vacuum at idle sits between 0-1. Ive done a compression test and all 4 cylinders came back with 1-2psi difference. Even a tuner hasn’t been able to find anything on the logs. So I’m turning to you guys! I am trying to post a data log as well! Thanks guys and gals!
 

·
Registered
Joined
·
853 Posts
Question is: who's doing your tuning? Vacuum idle should be closer to -.10 constant. Slight tap of the throttle into boost sounds like a tuning problem.

P0172 means running too rich - again - possibly the tuning. Have you had the purge valve replaced/recalled?
 

·
Moderator
Joined
·
1,732 Posts
When you said the "main" code it throws is p0172... thats implying there are other codes. Please list them all.
 
  • Like
Reactions: SSgtjrobertson

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #4
When you said the "main" code it throws is p0172... thats implying there are other codes. Please list them all.
That’s the only code it’s throwing. Occasionally it’ll pop up with misfires but that’s only after it fouls the plugs from running rich.
 

·
Moderator
Joined
·
1,732 Posts
Okay. Ill assume that the upstream Air fuel sensor was replaced, since you said all sensors are new. Have You attempted To disconnect the fuel feed from the Aux fuel completely To see if the issue goes away? You replaced the direct injectors but didnt mention the port ones. A hanging open port injector could cause this, whether its a mechanical Failure or the controller going bad and hosing fuel.
 

·
Moderator
2017 Kona Blue ST1
Joined
·
1,422 Posts
Okay, we're missing something here. If you're running rich enough to trigger a P0172 then there would be additional codes.

You mentioned aux fueling. How are you controlling the additional fueling?

You also stated an upgraded turbocharger and tune. Who is the tuner and what are the current AFR's @ idle / cruise /WOT?

You haven't really given us more that symptoms to work with here.
 

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #7
Okay. Ill assume that the upstream Air fuel sensor was replaced, since you said all sensors are new. Have You attempted To disconnect the fuel feed from the Aux fuel completely To see if the issue goes away? You replaced the direct injectors but didnt mention the port ones. A hanging open port injector could cause this, whether its a mechanical Failure or the controller going bad and hosing fuel.
I’ve completely removed the aux fuel from the equation and no change. I pulled the spacer and everything off and bolted the manifold straight to the head.
 

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #8
Okay, we're missing something here. If you're running rich enough to trigger a P0172 then there would be additional codes.

You mentioned aux fueling. How are you controlling the additional fueling?

You also stated an upgraded turbocharger and tune. Who is the tuner and what are the current AFR's @ idle / cruise /WOT?

You haven't really given us more that symptoms to work with here.
Aux fuel is controlled by the split second controller, but I’ve completely removed the aux fuel rail and spacer and bolted the manifold straight to the head. The tuner is Freedom motorworx and fabrication in oak ridge, TN. At idle AFT bounces from 13-16.6 along with the idle going up and down. And yes the upstream sensor was replaced.
 

·
Moderator
2017 Kona Blue ST1
Joined
·
1,422 Posts
Aux fuel is controlled by the split second controller, but I’ve completely removed the aux fuel rail and spacer and bolted the manifold straight to the head. The tuner is Freedom motorworx and fabrication in oak ridge, TN. At idle AFT bounces from 13-16.6 along with the idle going up and down. And yes the upstream sensor was replaced.
Rail pressure @ idle?

Cold engine with KOEO (key on engine off) what does MAP, Boost pressure, and Barometric pressure read?

If you flash back to stock (idle test only) and on an engine that is up to temperature, monitor AFR check to see if the issue remains.

I would be curious to look at some data logs.
 

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #10
Rail pressure @ idle?

Cold engine with KOEO (key on engine off) what does MAP, Boost pressure, and Barometric pressure read?

If you flash back to stock (idle test only) and on an engine that is up to temperature, monitor AFR check to see if the issue remains.

I would be curious to look at some data logs.
I will check these tomorrow morning. If you send me your email I can send some logs your way as well! Thank you
 

·
Registered
Joined
·
853 Posts
Still maintaining somethings not right with the tune. Are these guys familiar with ecoboost platform?

Also, did I miss what type of plugs you're running and what gap they're at?
 

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #12
Still maintaining somethings not right with the tune.
I’ve tried a stock tune everything was still the same. Although the idle was slightly better. Guessing since stock tune the idle is higher
 

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #14
Okay. While you get the info the others asked for, what plugs and gap are you running?
Ngk 6510 at .024 also tried brisk plugs at the same gap. Also tried to raise the gap to .028 with no luck
 

·
Registered
Joined
·
1,380 Posts
This sounds to me like you need to replace your Evap Purglr Valve line and then if that doesnt completely do it ur canister and solenoid in the back at the tank...what ur describing is almost exact symptoms of a failed purge valve and gas in ur charcoal cansiter from continuing to fill ur tank after it clicks to stop which we were all guilty of at some point.

But happens is that aolenoid in the canister fails if i understand correctly which allows fuel that shpuldnt be in yhe charcoal canister to be pulled through the hard line along with its fumes to the front of the car thru the purge valve into the ibtake mani which then makes you sit and idle rich and gives you stalling and ruff idle problems because your car sees fuel coming fron sonewhere else that its not injecting. Usually what your describing is fixed by just the evap purge line, and usually theyll blow the charcoal canister out if theres any fuel in it with like 20psi of compressed air you dont want to blow 50 or 100 psi thru it.

But again im not a certified tech, and i certainly dont have the knowledge like the likes of @SSgtjrobertson and @Duece McCracken have but sometimes I come up with the right thing at the right time...but not because i know alot...just because i read sometimes...hopefully ypu get this fixed.

I see you have a good bit done, when did this start?
Has it gotten progressively worse over time?

You have a 4port and BT I imagine at some point it wasnt doing this, was there anything you did or maintenanced or changed right before this started?
 

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #16
This sounds to me like you need to replace your Evap Purglr Valve line and then if that doesnt completely do it ur canister and solenoid in the back at the tank...what ur describing is almost exact symptoms of a failed purge valve and gas in ur charcoal cansiter from continuing to fill ur tank after it clicks to stop which we were all guilty of at some point.

But happens is that aolenoid in the canister fails if i understand correctly which allows fuel that shpuldnt be in yhe charcoal canister to be pulled through the hard line along with its fumes to the front of the car thru the purge valve into the ibtake mani which then makes you sit and idle rich and gives you stalling and ruff idle problems because your car sees fuel coming fron sonewhere else that its not injecting. Usually what your describing is fixed by just the evap purge line, and usually theyll blow the charcoal canister out if theres any fuel in it with like 20psi of compressed air you dont want to blow 50 or 100 psi thru it.

But again im not a certified tech, and i certainly dont have the knowledge like the likes of @SSgtjrobertson and @Duece McCracken have but sometimes I come up with the right thing at the right time...but not because i know alot...just because i read sometimes...hopefully ypu get this fixed.

I see you have a good bit done, when did this start?
Has it gotten progressively worse over time?

You have a 4port and BT I imagine at some point it wasnt doing this, was there anything you did or maintenanced or changed right before this started?
I’ve unhooked the purge valve from the intake manifold and plugged the hole to see if that may have possibly been the case. It didn’t change anything at all.
 

·
Registered
Joined
·
1,380 Posts
Yea im not sure if just plugging it is the way to test it, because your then eliminating the vacuum thays to exist on that emissions system so it may not function anymore normally you eliminating skmething thats supposed to operate correctly for the car to run correctly...i dunno tho.
 

·
Registered
Joined
·
1,380 Posts
I get your saying that should change the richness i guess your saying.
 

·
Registered
Joined
·
1,380 Posts
So besides that when this started happening, had you did any recent revisions to your tune? Added any parts, maintenanced anything?
 

·
Registered
2016 Race Red ST3, 2867r gen 2, 4 port aux, 380/380 at 26psi 93 oct
Joined
·
30 Posts
Discussion Starter #20
So besides that when this started happening, had you did any recent revisions to your tune? Added any parts, maintenanced anything?
I put in a new engine a week or two before it happened
 
1 - 20 of 21 Posts
Top