Error codes P0172 / P0175

[NoParticularName]

Hello,

I've recently buy a Mustang GT 96, and have the codes P0172 / P0175. The engine is not running so bad, but it's hard to start when it's cold. I did the follwing to try resolve this.

Actions :

• Changed the Fuel Filter
• Check the Long Term Fuel : -25% on both bank
• Fuel pressure : 31 PSI
• Fuel pressure without vaccum : 40 PSI
• Fuel pressure holding 15 min : 30 PSI
• MAF Cleaning
• Spark plugs changed
• Spark plugs wire changed
• PCV Valve to throttle including hoses
• Seafoam in tank (1 can)
• Changed the injectors

Observations :

• When the engine is cold, the starter crank 2-3 seconds and finally engine start.
• When I prime the pump more than one time, the engine starts right on.
• When engine is warm, it's starting well.
• Engine is bucking at low RPM when I push gaz pedal more harder. - SOLVED
• The exhaust gaz smells gaz, but I like that !
• Engine is leaking from the oil pan, and from the crank
• Fuel consumption is about 420 km / tank
• Car have no mufflers
• Get some idle problems, but the car is able to stabilize it. - SOLVED

Does the fuel pressure is a little bit low ? Does the codes could be related by this ? My goal is to get rid of thoses codes and setup the engine more efficient without throwing all my money. Your help will be welcome !

Thank you !

 

[Frank.JD.Perez]

not sure if this will help but try these

http://repairpal.com/OBD-II-Code-P0172-and-P0175

 

[NoParticularName]

Will do. I've just read and I didn't test the MAF Barometer, will check this out. I did cleaning it with cleaning stuff but still no changes.

 

[96blak54]

Without a dought, youll be changing the fuel pump out. Sounds to me like a weak pump.

Where you located at? Any pics of your car? Welcome to the site

 

[NoParticularName]

Without a dought, youll be changing the fuel pump out. Sounds to me like a weak pump.

Where you located at? Any pics of your car? Welcome to the site

The pressure is not too low below specifications but I find this pretty strange. The car has been stalled somewhere for a while and had to change some parts already. I'm located in Canada, Quebec province (where everybody talks French haha). Picture of the car is following ...

 

[NoParticularName]

Envoyé de mon SM-G920W8 en utilisant Tapatalk

 

[NoParticularName]

There is a picture of Torque App while I was driving at approximately 60 miles per hours. Again strange things ... the fuel pressure is probably not good ...

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[NoParticularName]

The "Baro" come from Android. Not possible the get it from the ECU

Envoyé de mon SM-G920W8 en utilisant Tapatalk

 

[JerZeyStangz]

Wow, this looks like my car when I first got it. I hope you get the issue resolved.

 

[NoParticularName]

Wow, this looks like my car when I first got it. I hope you get the issue resolved.

And what was the solution for you ?

UPDATE : My starting issues are probably cause by me ... I always tried to start the car while priming the fuel pump before. When my dad came to try it, he started it without staying on accessories position and it starts right on. Another thing ... When the car is running, I hear a sort of whistling in the dash. Is that possible to have a vaccum leak inside of it ? If yes, I'm in trouble ...

 

[JerZeyStangz]

I would start with basic maintenance first. Did you replace the fuel filter and did you clean the maf? Next I would look for some obvious hoses that look corroded. I couldn't tell you if there are vacuum hoses running through the dash board. I do not have vacuum schematics but when I pulled my cluster I didn't see any hoses at all. Right now I have current issue with a evap canister purge sensor and vacuum hose running to charcoal canister. If my car sits for a while it smells like fuel vapor then eventually goes away after a few days. I forgot what the code was but it gives me a rough idle when the car is warming up in open loop, when the car is fully warm and is in closed loop it doesn't show up as much.

 

[Thomas_W]

There are vacuum lines in the dash. They are a plastic line and rarely break or crack unless handled with gorilla gloves when the dash is removed for a heater core replacement.

 

[NoParticularName]

I would start with basic maintenance first. Did you replace the fuel filter and did you clean the maf? Next I would look for some obvious hoses that look corroded. I couldn't tell you if there are vacuum hoses running through the dash board. I do not have vacuum schematics but when I pulled my cluster I didn't see any hoses at all. Right now I have current issue with a evap canister purge sensor and vacuum hose running to charcoal canister. If my car sits for a while it smells like fuel vapor then eventually goes away after a few days. I forgot what the code was but it gives me a rough idle when the car is warming up in open loop, when the car is fully warm and is in closed loop it doesn't show up as much.

Yep, fuel filter and MAF cleaned. I did find a hose with a flatted spot near the brake lines. Tested it but there is no vacuum leak here. There is also a spark plug cable that was left on the engine and has heated, but here again, I dis sprayed some water on it and no spark so far. I will replace all of this eventually, and replace the spark plugs too.

There are vacuum lines in the dash. They are a plastic line and rarely break or crack unless handled with gorilla gloves when the dash is removed for a heater core replacement.

I hear the whistling at the drive side, but I only hear it in my garage, all doors closed. Really don't know if this is a vaccum ... Maybe ...

 

[NoParticularName]

Updates

Hi there ! There is some updates. I did change the spark plugs and wires. Also, I've did find a cracked hose on the PCV system, near throttle body. Ford sells only the whole assembly, so I did change it :

https://lmr.com/item/LRS-6324B/1996-01-Mustang-46L-2V-Gt-Pcv-Valve-Tube-Set

I did try to put a whole can of Seafoam in the tank. Someone have experience with this product ? I don't know if this is effective since I've change a lot of things .. Product was cheap, but basically I think I've lost 10$ CAD :slowclap:

Theses changes have definitely improved the car, it is now very stable, stoped to shake like shit and it's more friendly. I can now push the pedal all way down at very low RPM and no hesitation or jerking like before. I've noticed that is now very low torque, but have less juice at high RPM, maybe it's just an impression ... I will check if I did put back correctly the air intake. I get not rid of P0172 and P0175 yet, but it's better than before, so things are going forward. I don't hear the whistling anymore, specially when I stop the ignition, probably was the wasted PCV hoses.

I did buy a new set of injectors, I will received them shortly. If this is not resolving the "too rich" issue, I will change the fuel pump. I did find another hose that I'm finding suspect, like melted ... It's located behind the throttle body and goes somewhere near fuel lines ... I will simply change it.

 

[JerZeyStangz]

Glad to see some issues got resolved!

 

[NoParticularName]

Glad to see some issues got resolved!

Thanks buddy ! Oh man this car is so cool now, torque torque torque ...

Since the small updates, the car don't start very well when it's cold. It's starting every time, but starter is cranking longer ... I did test it, and it's start very well when I prime the fuel pump two times. My sequence is : Key Accessories ON, Key OFF, Key Accessories ON, Key OFF, Key all the way through without staying on accessories and BAM, it's starts like my new Ford Escape. If the engine is hot, I don't have to do this whole sequence.

I'm not a mechanical guy, but it's sounds to me that this the fuel pump or injectors. I will change both, no matter.

 

[Nighttrain]

A tune up goes a long way.

 

[JerZeyStangz]

Thanks buddy ! Oh man this car is so cool now, torque torque torque ...

Since the small updates, the car don't start very well when it's cold. It's starting every time, but starter is cranking longer ... I did test it, and it's start very well when I prime the fuel pump two times. My sequence is : Key Accessories ON, Key OFF, Key Accessories ON, Key OFF, Key all the way through without staying on accessories and BAM, it's starts like my new Ford Escape. If the engine is hot, I don't have to do this whole sequence.

I'm not a mechanical guy, but it's sounds to me that this the fuel pump or injectors. I will change both, no matter.

Mine takes about 1-2 seconds to start. My fuel pump has been upgraded recently as well. My hunch is that the FPR is old and need to be replaced. I am due for a tune up as well.

 

[Nighttrain]

Go with an adjustable fpr, so youre set for any future upgrades

 

[JerZeyStangz]

Go with an adjustable fpr, so youre set for any future upgrades

I actually have a adjustable one collecting dust in my room. I bought it off a vendor a few years ago for a manifold I never installed. What should it be set to and would this mess with stock settings/tune?


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