After WOT run car won't run, with really rough idle

[JeremyH]

I still suspect vac issue. but here is some info on the code.

P2197

Lack of HO2S-21 Switch, Sensor Indicates Lean

Detailed Description

A heated oxygen sensor (HO2S) indicating lean at the end of a test is trying to correct for an over-rich condition. The test fails when the fuel control system no longer detects switching for a calibrated amount of time.

Possible causes :-

Electrical:

# Short to VPWR in the harness or HO2S.

# Water in the harness connector.

# Open/shorted HO2S circuit.

# Corrosion or poor mating terminals and wiring.

# Damaged HO2S.

# Damaged powertrain control module (PCM).

Fuel System:

# Excessive fuel pressure.

# Leaking/contaminated fuel injectors.

# Leaking fuel pressure regulator.

# Low fuel pressure or running out of fuel.

# Vapor recovery system.

Induction System:

# Air leaks after the mass air flow (MAF) sensor.

# Vacuum Leaks.

# PCV system.

# Improperly seated engine oil dipstick.

EGR System:

# Leaking gasket.

# Stuck EGR valve.

# Leaking diaphragm or EVR.

Base Engine:

# Oil overfill.

# Cam Timing.

# Cylinder compression.

# Exhaust leaks before or near the HO2S(s).​

 

[555]

Friend of mine had an issue similar to this with e85 fuel, found his fuel sock corroded and filled his filter

 

[Sonicblue_s197]

I'm thinking it's gotta be a fuel issue now. Fuel pressure reads 40 psi while it's idling. But my guess would be file filter is plugged or fuel pumps are done.im Gunna go over a couple things you mentioned on that list and go from there thanks Jeremy. Il also be calling my tuner tomorrow and see what he says.

 

[BruceH]

I'm thinking it's gotta be a fuel issue now. Fuel pressure reads 40 psi while it's idling. But my guess would be file filter is plugged or fuel pumps are done.im Gunna go over a couple things you mentioned on that list and go from there thanks Jeremy. Il also be calling my tuner tomorrow and see what he says.

Fuel pressure is supposed to be right around 40 at idle. Unless the rail sensor is bad you are getting the proper amount of fuel.

Edit: Have you checked the bypass to see if it's stuck open?

 

[JeremyH]

Fuel pressure should be closer to 28-30psi at idle with proper vacuum to the frps. But in his vid looks like he has no vacuum his gauge was hovering around 0-5 vac which would force fuel pressure higher if the frps was working properly.

Even so at 40 psi that's plenty to drive the car, I drove my car at 50mph with only 10psi rail pressure.

 

[BruceH]

Fuel pressure should be closer to 28-30psi at idle with proper vacuum to the frps. But in his vid looks like he has no vacuum his gauge was hovering around 0-5 vac which would force fuel pressure higher if the frps was working properly.

Even so at 40 psi that's plenty to drive the car, I drove my car at 50mph with only 10psi rail pressure.

The sensor will report 39.15 if that's what is commanded. I understand the part about pressure differences but if you were to datalog a tune that's commanding 39.15 throughout the rpm range it will be close to 39.15 at the frps.

 

[JeremyH]

Correct, but due to vacuum in the manifold at idle, actual fuel pressure in the rail as read by a standalone fuel pressure gauge like the op has will read less. I see around 28psi rail pressure at idle with sock 39.15psi delta commanded by the tune. The pcm sees 39.15 psi due to the vac reference at the frps but a fuel pressure gauge at the rail will read whatever it actually is depending on vac or boost.

His fuel pressure gauge is reading 37-40psi which makes sense for 0-5 vac (0 to -3psi is)

Op what is your normal idle vac on your setup? You have a huge vac leak it seems.

 

[Sonicblue_s197]

No I didn't check the bypass valve I will take a look at that next. It usually sits right at 15 for vacuum at idle

 

[JeremyH]

So your fuel pressure on your autometer gauge would normaly be around 32psi at idle ( 1in of vac is -2psi).

Looks to me like the frps and fuel pressure is fine based on your super low vac.

Everything okay with the blower?

 

[Sonicblue_s197]

My fuel pressure gauge is never under 40 psi even at idle, it's a triple pump return style fuel system. and jumps up to around 55 psi under load but the blower is fine nothing wrong with it, this whole setup has less then 2000 miles on it.

 

[psfracer]

But in his vid looks like he has no vacuum his gauge was hovering around 0-5 vac which would force fuel pressure higher if the frps was working properly.

Even so at 40 psi that's plenty to drive the car, I drove my car at 50mph with only 10psi rail pressure.

No I didn't check the bypass valve I will take a look at that next. It usually sits right at 15 for vacuum at idle

Doesn't this indicate a severe vacuum leak?

 

[RetroGT2006]

Subscribed, I am interested to know what is causing this issue..

 

[t3itguy]

Well I checked all the piping and they were all on right checked for vacuum leaks didn't find any, I even took off the frpp throttle body and put the stock one on and it still runs like crap, I'm Gunna pull the plugs tomorrow and check them out . It it threw 2 codes one was p2197 and the p2195 lean condition. I don't no what else to look for the throttle does not work at all I push it down and stays the same. I'm Gunna replace the fuel filter also . Any other ideas?

My car ran exactly the same way a while ago because I pulled a vacuum line off to see what it would do. It was the one on the driver's side that ran between the intake manifold (red circle) and that emissions doohickey on the driver's side strut tower (red arrow). I'd check that bad boy out. I'm like 62% sure if you take that hose off the intake side and cover up the port on the intake manifold, it should run fine again. If it does, check that line for vacuum leaks, and check the emissions thing to see if it holds vacuum. It could be damaged because of boost.

 

[Sonicblue_s197]

Il check that out when I get home in a few

 

[Sonicblue_s197]

Well I'm dropping off the car at the shop today so hopefully it's nothing bad, I did notice I tried to start the car up this morning but the battery didn't have enough juice all my gauges worked but my oil pressure guage went 1/4 of the way up then went back down, not sure if that's normal since I didn't start the car just turned the key forward.

 

[t3itguy]

Well I'm dropping off the car at the shop today so hopefully it's nothing bad, I did notice I tried to start the car up this morning but the battery didn't have enough juice all my gauges worked but my oil pressure guage went 1/4 of the way up then went back down, not sure if that's normal since I didn't start the car just turned the key forward.

Yeah, that should be fine. Did you ever figure out the problem?

 

[Sonicblue_s197]

It's still at the shop I haven't heard anything yet, when I dropped it off he figured it might be wiring on the fuel system, a couple weeks ago he installed a fore boost activated switch to only have 1 fuel pump running while cruising and if it went over 5 psi it would kick the other 2 pumps on, Il be giving then a call tomorrow for an update.

 

[Sonicblue_s197]

They called me yesterday on the car and they pulled the intake off and found a couple of cracks on the runners, and under the throttle body, he had an intake laying around so he threw it on and it pretty much fixed the issue until I can run out there and take him my jpc racing intake. I'm pushing 22 psi right now so I'm guessing these stock intakes are good to around 20 psi.

 

[BruceH]

They called me yesterday on the car and they pulled the intake off and found a couple of cracks on the runners, and under the throttle body, he had an intake laying around so he threw it on and it pretty much fixed the issue until I can run out there and take him my jpc racing intake. I'm pushing 22 psi right now so I'm guessing these stock intakes are good to around 20 psi.

Good to see you found it. So you cracked the intake with a wot run and had a subsequent vacuum leak, is that the synopsis?

 

[Kylar]

Wow, cracking the intake is impressive. I thought it could handle more abuse, makes you wonder about the ford upgrade that is also plastic...