Can you tell if the fuel pump is running all the time?

0452 is the Tank Pressure Sensor - listed as typically a poor wire connection. so with that just unhooked it seems possible.

0191 - could be low or high fuel pressure (and other possibilities) is your scan tool showing low pressure?

1120 - odd, listed as most likely a poor connection as well - might fiddle with that one again.

Wild possibility that wiring to the fuel tank is the cause of everything but the throttle position sensor code. Power to the pump & a short to ground in the wiring could let it run constantly (key on), leading to the rich running? Lack of a good TPS signal possibly making it worse.

WAG's here (Wild Ass Guesses) just from looking at codes & the OBD info link IMINHELL stickied.

Luck Carl!

 

Key on, do a sweep test of the TPS. You can use the Xcal and log Throttle Position Absolute. The data will be in counts. You should see something around 200 at closed throttle and increasing as you open it. It should not go above 1080.

If that does not happen, or the rise isn't as smooth as you foot is pushing, there is a problem with the TPS itself.
If the data is choppy, check the wiring. Corrosion or loose pin could be to blame.

The tank pressure one is for EVAP. That tells the solenoid if it should open or not. If there is high pressure in the tank, it opens. Low it closes.
If there is a leak it will think it's low, but will catch it when it does a self test ... that's where the 'small evap leak' and such come from.
It's also the wiring that would have been to the drivers side of the fuel pump wiring, and unfortunately it's not accessible unless you drop the tank ... there is no grommet to peek through either.


My best guess, the TPS is the main cause. The engine is going into fail safe but with the tune, fail safe is confused.


If you also datalog Fuel Source and Spark Source, they might help. It'll at least tell a guy if it's fail safe or something else. Click the Help button in Live Link and then Source Values. It'll explain what the source numbers mean.

 

Could it be possible that the TPS is bad and needs replaced?

 

It might, but then the question of why is it defaulting to running so rich? In stock form, that isn't what's supposed to happen. So I kinda think there's more than one problems here.

 

Would you happen to know how to diagnose a bad fuel tank pressure sensor?

Edit:
I did some more homework and it sounds like the Fuel Tank Pressure Sensor. My car is displaying all of these symptoms:
http://www.buzzle.com/articles/symptoms-of-a-bad-fuel-pressure-regulator.html

 

Carl - without even reading that article in detail, noticed that it refers to fuel pressure regulator.

Your version of that is the 0191 code for the pressure sensor (at the fuel rail). Check the DTC info in the stickies, that particular one is most likely high or low pressure - less likely a sensor failure.

Tank pressure sensor is only used for checks on the vapor recovery system, doesn't affect running.

Hope that helps a bit.

 

Did you do anything under the hood while the tank was out?

Tank pressure sensor by itself is easy to explain since the wiring was unhooked for the tank job and that code lists poor connection as the most likely issue.

Both fuel pressure out of range/defective sensor, AND the code for Throttle position sensor issue at the same time is odd.

Iminhell's first line on a "sweep test" of the throttle position sensor sounds like a good first step to see what's going on there. Since you've got a scan tool, plugging it in & checking readings while you move the pedal would be better than trying to check it with a multi-meter.

See if that scan tool can give you a fuel pressure reading as well, don't have that type so I don't know all it's options - would guess it's an avail. reading.

 

No, I didn't do anything under the hood while the tank was out.

 

Give me a call 704 249 3745

Tom

 

I replaced the Fuel Tank Pressure Sensor and spark plugs and it took care of the P0191 code, but I'm still getting the other two. Also, I noticed the the fuel pump is making a weird noise. It's a different noise than the bad pump I replaced, but it didn't make the noise on Saturday when I replaced it.

Tom, I've been busy at work and meaning to call you. I'll try today if I get the chance.

 

Mixed up on what you replaced Carl, 0191 should be the fuel pressure sensor - on the fuel rail.

 

No, that's what I replaced. FTPS is what the part is called.
http://www.autozone.com/autozone/pa...sor/_/N-jmnteZ8vdtr?filterByKeyWord=fuel+tank+pressure+sensor&fromString=search

Also, I tried to Google how to do a Sweep Test, but couldn't find anything. I also looked on my XCalIII for the "Sweep Test" option, but couldn't find anything on that either. Can someone explain how to set things up for a sweep test?

 

sweep test isnt going to do anything , just hold in the ODO clear peg why turning on the key till you see the gauges sweep or about 5 -7 sec then release

Tom

 

TPS Sweep Test
[poke]

Good video --> http://www.youtube.com/watch?v=8KfKfImoIXg

 

I'm still stumped on the P0452 code. I've been looking at the different components to the EVAP System and can't figure out where I should start looking.

 

Something's Wonky with those codes, Fuel Tank Pressure Sensor should have affected the P0452 if it was the problem causing that.

P0191 is related to the Fuel Pressure sensor on the fuel rail, so the tank sensor shouldn't have changed that.

And you're left with the Throttle Position Sensor one that Iminhell just commented on...

Oh Fun.

 

UPDATE:

I'm still trying to figure out what is going on with my car. So far, I've replaced the fuel pump, fuel pressure sensor, the TPS and MAF. It hasn't thrown any codes recently since replacing the sensors. The car is beyond my troubleshooting knowledge know and I can't afford to take it into a shop. The only thing I can think of right now is to take a video clip of what it's doing and share with you all.

 

Hey Carl, is that thing still got the same running rich problem?

Just to ask the silly questions, is the fuel pressure looking good now?

How about the Turbo, vacuum/boost gauge showing normal reactions? You didn't mention any smoking, did you look in the plumbing for oil or give the turbo a finger spin if the boost reaction seemed off?

 

It's not smoking, but it does spit out visible carbon bits out of the exhaust pipe. My AFRs will peg out at 10.0, then the car stalls. It still runs rough and. I have to keep my foot on the accel to keep it running. I did a visual inspection for anything that could be disconnected to cause a vac leak, but couldn't find anything.

 

I did a visual inspection for anything that could be disconnected to cause a vac leak, but couldn't find anything.

That's not going to tell you much.
99% of the time you'll never see a vacuum leak. Just look at all the 'stumbling' issues and the PCV hose collapsing. Most of those people never see anything until they take things apart, and it crumbles in their hand.

Do the old pressure test,

How to build an Intercooler Pipe Pressure Leak Tester

Parts Needed:

• A 4 inch long piece of 2.5" O.D. (outside diameter) hose. (I used some radiator hose I got at NAPA)
• 1.5" I.D. (inside diameter) PVC end cap.
• 2 band clamps that will fit around the 2.5" pipe above.
• A valve stem (I used the rubber type you press in)

Note that if you have a larger turbo, the sizes of the end cap and hose may need to be larger in order to fit the turbo inlet.

• To assemble, just put everything together as shown.

• To assemble, just put everything together as shown.

• To get the valve stem in, I had to drill a hole in the PVC cap.

To use it, just remove the intake pipe from your turbocharger inlet, and attach this in its' place.
Now you need to hook something up to the valve stem to pressurize the intake so you can listen for leaks. I use a 7 gallon air tank I got from Walmart, I just fill it up with air at the local gas station. You can also use a simple bike pump.
If you have a manual boost controller hooked up, you might want to plug off its' intake hose, as they leak a lot of air, making it hard to pinpoint the real leak.
Pressurize the system, and listen all over for leaks. Make sure you or a friend listens under the bumper too, wherever there is IC piping.
A leak will be obvious, they make a loud hissing sound.
You might want to have a friend check out your boost gauge while you are pressurizing things, to make sure you don't put too much pressure on things. (20 psi should be safe, or whatever you run safely for boost)
Places I have heard of leaks occuring:

• BOV flange
• Intake manifold ports
• Throttle Body gaskets
• Holes in the intercooler
• Holes in the intercooler piping (sometimes the rubber pipe inside the stock woven mesh pipes cracks, and you can't see it from the outside... the pressure tester will find it though!! )

Pictures and Text by Brent Cook
Idea for tester from Josh Wingell
Contact bacook@mediaone.net for questions.

(since I can't give a direct link)




Granted you won't use the exact parts/sizes. But you get the general idea. Just make a plug for the inlet side and pressure test for leaks. You don't need wild pressure, a couple pounds will easily show a leak.

 

I smell an unrelated electrical problem- the evil coincidence. Are you handy with a tester? Got diagrams? I seriously doubt that many sensors would fail at one time, but one grounded wire could do it.

Did you pull the plugs to see if one looked different than the others?

 

I've thought about the pressure test, but it's looking like I'll have to stop thinking about it and do it.

I not that familiar with electrical stuff. When I changed the plugs they were all saturated with carbon build up.

 

I've thought about the pressure test, but it's looking like I'll have to stop thinking about it and do it.

I not that familiar with electrical stuff. When I changed the plugs they were all saturated with carbon build up.

That's what we're here to help with, lol.
The carbon is just a sign of it running rich. Which you already know from the WBO2.

Test for a leak first. You understand the basic mechanics of how things should work. So knock that task out and then move on to things you might not know so well.
We can teach you what things to datalog and how to interpret them to nail down where the problem lies. It just takes a bit of time and conversation.

 

A friend mentioned the possibility of the timing chain jumping a tooth or even a failure in the ECU software. I've never heard of timing jumping a tooth with a chain. What's ya'll's take on it?

He also mentioned the possiblity of a faulty crankshaft and/or camshaft position sensor.

I'm going to search for a vaccumm leak tonight after work.

 

Chain won't jump.
It can however slip on the crank. The Duratec is a slip fit, no keyway. So if the bolt comes loose or looses TQ, it might be possible for it to move. But i don't recall anyone having a problem with this.

 

Man quit copying my test fixtures! I use them things on everything and they are supposed to be a secret!!!

 

Well, after chasing some electrical gremlins down, it turns out that something fried in my ECU that is the cause of my problems. This sux.

 

The ECU doesn't just fry. So it may be a symptom, not a cause.
Keep digging.

If you know what died in the ECU, then you can narrow the search, maybe enough to pinpoint the problem.


It's very odd for an ECU to take a dump. So think back to electrical modifications you've made, any deep water (or windows leaking) or water leaks, any connectors you've had apart (maybe a pin got loose) or similar.
There is a very good chance something you did or went through is the root cause. And until that is found, you'll be back in the same boat eventually.

 

Not nice, we depend on that to work right unless totally fried.

Luck Carl - love to know what you find out, it's been a puzzlement.

 

I've been researching replacement ECUs most of the afternoon.