Final call for help

[GenesisRed]

Hi guys (and gals?)

I have a long running problem with my puma. You can read the whole unhappy tail here: http://www.projectpuma.com/viewtopic.php?t=12660" onclick="window.open(this.href);return false;

Anyway, it basically cuts out at idle once it is warm and struggles to restart. I have taken it to the garage a number of times, and changed and looked at a number of things in vain (inc MAF, fuel injector, filter, pump).

The RAC have been out and collected me a number of times (to the extent that they won't any more!) and have given me readouts as best they can on their machines. The upshot is that the error being recorded is that the fuel level sensor is reading no fuel even when there is fuel in there. At the same time, the fuel gauge on the dash is reading correctly.

Can anyone explain to me how this can be? Are there two sensors in the tank? Are there two cables leading from the sensor and one of them is broken?

The EVAP system seems to function (at least, it purges - I sat with an RAC guy for ages going through all the options on his computer), but on reading around (such as here: http://www.ls2.com/boggs/dtcs/DTC%20P0440.htm" onclick="window.open(this.href);return false; ) it appears that the EVAP system won't function properly if it is receiving an inaccurate reading on fuel level.

So, this is the final role of the dice really. I've spent more money than my better half is happy about chasing this problem in vain, and i'm hoping someone can help me find the answer that will give me back my car. Else its a grand's worth of car going on the heap or the cheap.

HELP!

Thanks

 

[danielz000]

"Fuel tank ventilation is achieved through a fuel tank rollover valve (into an evaporative emission canister). The fuel tank rollover valve prevents fuel loss from the fuel tank if the vehicle becomes inverted."

Apparently it's located about 6 inch backwards from the passenger side door about 2 inch higher than the handle...

No idea how to get to it tho... Maybe by pulling out an interior panel? Best ask about first though...

I'd really have a go at clearing out the ventilation pipe for the fuel tank try running a long piece of wire down it

Were neither of these posts any use to you?

Are you sure that removing the petrol cap temporarily fixes the problem?

 

[GenesisRed]

Hi

Since the last time, i've not tried anything other than driving with the petrol cap off - which did nothing. Couldn't even imagine why it seemed to help before, but it doesn't help to drive with it off!

AS far as the other suggestions (which I appreciate your thought on), the error message was P0460 - Fuel level sensor circuit malfunction - so I have to resolve that first.

Looking around the world i've found this...

Re: Fuel level sensor circuit malfunction (P0460)?

P0460 - Fuel Level Sensor Circuit Malfunction The PCM monitors the fuel level input (FLI) circuit for electrical failure. The test fails when the signal moves outside the minimum or maximum allowable calibrated parameters for a specified fuel fill percentage in the fuel tank. Empty fuel tank
Fuel pump (FP) module stuck open
Incorrectly installed fuel gauge
Damaged instrument cluster
CASE GND circuit open
FLI shorted to VPWR
Damaged PCM
Overfilled fuel tank
Fuel pump (FP) module stuck closed
Damaged fuel gauge
FLI circuit open
FLI circuit shorted to CASE GND or PWR GND
CSE GND shorted to VPWR
Monitor FLI PID and FLI V PID in key ON engine RUNNING. FLI PID at 25% fill (with non matching fuel gauge) and FLI V PID less than 0.90 volts [for FLI PID at 75% fill (with non matching fuel gauge) and FLI V PID greater than 2.45 volts] indicates a hard fault.

What they are saying here is that the PCM is recieving a voltage from the fuel level sender that it recognizes as invalid. This means either the voltage is shorted to power or the line is dead, 0v. given your other symptoms, I would expect to find a wiring problem. Either a bad ground wire or a melted harness. Of course it could also be a bad cluster. I would start with taking out the instrument cluster and cleaning the connector with some corrosion fighter and inspecting the wires very closely, making sure to reconnect it correctly.

What gets me still is that, if the fuel sensor is the problem, why the hell is the fuel gauge (apparently) working correctly. I get that if the assorted processors don't get the readings they expect they call an error.

Filling up the tank half way (so it's between the 15% and 85% levels) doesn't seem to help, although I never get far enough to let it settle down.

 

[GenesisRed]

Incidentally, i stumbled across this before (referring to the Focus) which, though intriguing, doesn't really answer why the hell one "thing" receives a fuel level and another doesn't. Also, someone on here suggested it was a bad idea to use a fuel cleaner... at this point, maybe its no harm trying it (if i can find an equivalent). After all, the petrol i had been using was supermarket, and driving on vapours quite alot...

I contacted a person in NC who works at a dealership and he said,

"Do this first. Go buy some Chevron Techron fuel system cleaner. Dont use any other, this is the one Ford says use. Try to have your fuel tank close to empty before you do this. Once you have it that low, fill the tank with a good grade of fuel, dont use cheap fuel or no-name fuels, and add the Chevron. Clear the CEL and drive the car for awhile, it should take care of it. The fuel card in the tank is getting dirty from cheap or no-name fuel. If youre using a well known fuel maker, try a different brand."

I did this and it fixed the problem. I hope that this will help someone else some day!

19098 MULTIPLE VEHICLES - SULFUR BUILD-UP ON FUEL LEVEL SENSOR - ADD "CHEVRON TECHRON PLUS FUEL SYSTEM CLEANER" TO FUEL AND FILL WITH FRESH FUEL
GASOLINE OR DIESEL VEHICLES MAY EXHIBIT ERRATIC FUEL GAUGE READINGS, ILLUMINATED MIL, AND DTC P0463, P2068 AND/OR B1202, B2627 MAY BE PRESENT. THIS CONDITION MAY OCCUR DUE TO SULFUR CONTAMINATION FOUND IN SOME LOCAL FUELS WHICH MAY CAUSE TEMPORARY CONTAMINATION OF THE FUEL SENDER CARD. BEFORE REPLACING ANY COMPONENT, CLEAR DTC'S, DRAIN FUEL TANK (IF FACILITIES PERMIT), ADD TECHRON CONCENTRATE PLUS FUEL SYSTEM CLEANER AND ADVISE CUSTOMER TO USE AN ALTERNATE BRAND OF FUEL. THE CONDITION SHOULD CORRECT ITSELF IN A FEW MILES. ADVISE CUSTOMERS TO UTILIZE THE TRIP ODOMETER TO MONITOR FUEL CONSUMPTION. REPLACEMENT OF COMPONENTS OR PCM REPROGRAMMING MAY NOT FIX THE CONCERN. IF CONCERN PERSISTS PERFORM NORMAL DIAGNOSIS AND REPAIR. OBTAIN THE NEW TECHRON PLUS FUEL ADDITIVE LOCALLY FROM YOUR LOCAL AUTOMOTIVE CHEMICAL SUPPLY SOURCE OR AUTO PARTS STORE.

 

[danielz000]

What gets me still is that, if the fuel sensor is the problem, why the hell is the fuel gauge (apparently) working correctly. I get that if the assorted processors don't get the readings they expect they call an error.

It could just be a blip in the voltage which causes it to trip out. The needle probably wouldn't move quick enough to display it.

I'll try looking up P0460 on TIS and AutoData tonight for you, see if I get any better information. Did you try cleaning the contacts to make sure the connection was good? Are you having any other strange electrical problems?

I would also check whether that hissing noise is normal when you remove the cap. I'll check it on my car but I don't have a standard cap...

 

[yippeekiay]

I've wrote about 5 replies and each time I keep thinking I'm wrong or talking complete nonsense so in short. Had a bloody good look at the TIS and could find nothing of help as it kept saying use the diagnostic machine....lol.

Do you actually know HOW the car cuts the engine when it gets a bad or incorrect reading??? i.e. does it cut the fuel or the ignition?

Once you know that I would check to see if that is actually happening. If it is then you know your on to something. If it's the opposite then you know your barking up the wrong tree.

It'd be worth checking what that person wrote on the quote above regarding bad ground, wiring or even the cluster. The cluster MAY be giving a correct reading but as it says, it doesn't mean the ECU is getting the same reading. The reading the ECU gets MAY actually be coming VIA the cluster and not direct from the fuel sender so the problem may lie there. Let's hope eh? k:

 

[danielz000]

Probably causes from AutoData: Wiring, Fuel Tank Level Sensor, ECM

I would start with checking all the fuel tank connectors mate...

 

[lb81]

Hi guys (and gals?)

Can anyone explain to me how this can be? Are there two sensors in the tank? Are there two cables leading from the sensor and one of them is broken?

The fuel pump / fuel level sender are a combined unit so essentially two in one. One set of wires and loom but the possibility of a malfunction but still a correct fuel gauge reading.

I know how frustrating tracking down this type of problem can be, so a couple of things that may help...

* Firstly do you have a copy of the Haynes manual (Fiesta 3397)? If you don't I would advise getting one before you spend any more money on anything for the car. Even if you have no intention of actually doing any spanner work yourself if you have an oldish car it can be invaluable to help diagnose problems and help you to speak with a garage etc in an informed manner...

* Before doing anything else, I would check the condition of ALL the wiring related to the fuel / ignition system, both within the engine bay and under the car as far as is accessible without dropping the tank. I would also locate all of the earthing points I could find to make sure none are corroded or broken. A bad earth or corroded/broken wire somewhere could quite easily cause the symptoms you have described as the problem appears to be motion related as things move about.

* I would then take a deep breath and start again from the beginning and check the fuel pump operation, the fuel pressure return, the pressure regulator, the emergency fuel cut off (or 'roll over valve') is not activating for some reason, check the fuel tank vent pipe is clear - and I mean check it all again from the start and forget for the moment that this or that has been checked or changed already. The Haynes manual will explain how to check all these things yourself and most of it is fairly straight forward and requires nothing more than some time and patience.

IMO the ONLY way to get to the bottom of this sort of problem is to adopt a methodical approach checking the simplest and most obvious things first and taking nothing for granted.

Even a garage wont necessarily be a great help, as you have experienced already, most will just plug in their laptop, check for fault codes and start telling you to replace this or that part rather than diagnose the problem properly but I wont start an anti garage rant on your thread :roll:

I also would not put too much store in the fault code suggesting the faulty sender as it looks to be a bit of a PITA to change and from the symptoms you describe I will be amazed if the problem does not turn out to be either electrical or fuel pressure related.

Whatever happens I really hope you find the cause and get it sorted soon as possible and the Puma does not end up in the bin

 

[ScubaSteve]

loom to fuel pump goes inside the car, you can see it in my project thread when im spraying

 

[lb81]

accessible via the access hole in the floor I would imagine!?

 

[XIIVVX]

After all, the petrol i had been using was supermarket, and driving on vapours quite alot...

Red herrings.

Neither activity is in any way detrimental to your Puma.

(Unless it was supermarket diesel :shock: )

Good luck solving your problem

 

[GenesisRed]

Thanks all for your excellent help and advice.

The wiring loom has a couple of supporting votes, in particular from one RAC guy who spent ages on it, and then said that it "must" be the wiring loom. One way or another, it sounds electical. That it only seems to happen when the car gets up to temp makes me worry that its a wire broken inside somewhere that expands away when hot.

Looks like i'll have to get a Haynes manual and get looking... although getting to it all safely may prove to be a problem. And I mean safely in relation to the girlfriend not just the car falling on me!

I'll let you know how it goes.

Alternatively, if any of you want to buy a Puma that needs a little bit of work, and which has a number of good new parts for £250 ono (new parts are probably worth most of that alone), then drop me a line! Other than fixing this, it should only need new shocks at the back.

 

[danielz000]

What's up with the shocks? Might be worth sticking a post in the for sale section. I suspect at that price you're going to get your arm taken off.

Where in London are you? I might even take it off you...

 

[yippeekiay]

Jesus - if I wasn't so bloody far away I'd give you £250 now.

 

[GenesisRed]

link here if you're interested in taking it on as a project: http://www.projectpuma.com/viewtopic.php?f=29&t=13922&p=178201#p178201" onclick="window.open(this.href);return false;

location is near greenwich.

 

[jonnyb]

Not too sure if this is helpful at all but here it is:

I used to own an old Rover Metro a few years back and it suffered the same symptoms you described in the OP, the car would start fine, drive fine until the engine had reached normal operating temperatures then the car would just cut out. This happened every day without fail, a very very annoying problem! The car would also take a lot of effort to get started again (would have to keep trying to turn the engine over with foot to the floor and eventually it would take and start up).

Soo I believe I eventually found the cause of this problem - a dodgy fuel tank, I noticed my fuel tank had a bit of a leak and so decided to replace it, whilst waiting for a replacement a mechanic took the rubber seal out from my fuel cap and this seemed to help with the issue. After replacing the tank the problems seemed to disappear.

Hope this may help in some way.

Jonny