Technical Panda not starting - Diagnosis correct?

[pot51e]

Hi All,
My son inherited his sisters 2008 100hp Panda 3 in November and has had intermittent starting issues since he got it. Drives great when it goes, but last week this starting issue progressed to loss of power 2 mins after start and no start since. I've done a bit of diagnosis and think its the fuel pump - hopefully someone can validate/correct before it goes down the road for a new one and I spend more money on it!

We already had it in the local garage:
new battery, new earth braid, new crank sensor, new oil filter (noticed an oil leak 2 or 3 weeks prior) and new plugs.
While fault finding myself, found a fuse had popped (F11).

Ignition I : lights come on as expected, immobilizer light goes off, fuel gauge shows full.
Ignition 2: Engine turns over but doesnt fire.

After searching for a fuel pump fuse or relay (both listed at f21 or r14) - found neither to be present - presume this is handled elsewhere?

Took seats out and confirmed Fuel pump doesn't energize at ignition 1. Checked inertia switch under passenger.
Then checked voltage at ignition 1 - 6v for about 2 seconds? Not sure about this, so I ran a 12v direct to purple/yellow - and got nothing.

Guess I'm wondering why Id get 12v a purple/yellow at the fuse box (connector coming out) and only 6v at the pump (guess it could be bad connection by me checking).

So presuming I ran 12V to pump (and purple/yellow is correct line!) and it didn't energize - new fuel pump?

Any help appreciated

Cheers!

Rick

 

[The Panda Nut]

Hi All,
My son inherited his sisters 2008 100hp Panda 3 in November and has had intermittent starting issues since he got it. Drives great when it goes, but last week this starting issue progressed to loss of power 2 mins after start and no start since. I've done a bit of diagnosis and think its the fuel pump - hopefully someone can validate/correct before it goes down the road for a new one and I spend more money on it!

We already had it in the local garage:
new battery, new earth braid, new crank sensor, new oil filter (noticed an oil leak 2 or 3 weeks prior) and new plugs.
While fault finding myself, found a fuse had popped (F11).

Ignition I : lights come on as expected, immobilizer light goes off, fuel gauge shows full.
Ignition 2: Engine turns over but doesnt fire.

After searching for a fuel pump fuse or relay (both listed at f21 or r14) - found neither to be present - presume this is handled elsewhere?

Took seats out and confirmed Fuel pump doesn't energize at ignition 1. Checked inertia switch under passenger.
Then checked voltage at ignition 1 - 6v for about 2 seconds? Not sure about this, so I ran a 12v direct to purple/yellow - and got nothing.

Guess I'm wondering why Id get 12v a purple/yellow at the fuse box (connector coming out) and only 6v at the pump (guess it could be bad connection by me checking).

So presuming I ran 12V to pump (and purple/yellow is correct line!) and it didn't energize - new fuel pump?

Any help appreciated

Cheers!

Rick

Your logic sounds good it looks like the pump. Next job, get the thing out and see if it runs wired directly but on the bench.

 

[koalar]

Don't just run wires in an unknown possibly faulty circuits

Just suppose there had been a short inside the motor wirings could end in a very bad day

F11 supplies voltage to the o2 sensors and evap

So nothing to do with the pump. There is a yellow and purple wire here also are we measuring the correct one at 12v

 

[koalar]

Then checked voltage at ignition 1 - 6v for about 2 seconds?

Where is this being measured

 

[pot51e]

Where is this being measured

Hi, thanks for the response!

I was measuring 6v at the pump connector block, on the purple/yellow (should correctly say Violet/Yellow) line for about 2 seconds at ignition 1.
Figured I should expect ~12v, but not being a car guy figure maybe it's perhaps parallel with something, as there's <5 ohm drop from Violet/Yellow connector @ connector, assumed this was a good line

As for F11 - yeah I discounted it in this circuit, but thought it worthy of mention as to what has been done.

While I was cleaning that I saw Purple/yellow coming from F22 and as you allude to, not having a wiring diagram available doesn't aid matters!

Appreciate your help

Rick

 

[pot51e]

Your logic sounds good it looks like the pump. Next job, get the thing out and see if it runs wired directly but on the bench.

Cheers - not 100% sure if that's a job I can get my arms round or just get the local garage to do!

Appreciate the response!

Rick

 

[koalar]

I was measuring 6v at the pump connector block, on the purple/yellow (should correctly say Violet/Yellow) line for about 2 seconds at ignition 1.

Should be battery voltage

Here's mine tested, back probed

Take the pump out of the equation, should measure battery voltage disconnected

Finding a decent earth at the back isn't easy, the seatbelt bolt is about the only thing that isn't painted

 

[berlinasportiva]

Maybe will help, we had fuel cutout switch cracked in our 100hp which caused similar issues, maybe give it a go?

 

[koalar]

Take a short video of the dash

Switch the ignition on
Then crank the engine

I want to see the behaviour of the engine check light, battery, oil, rev counter

 

[pot51e]

Take a short video of the dash

Switch the ignition on
Then crank the engine

I want to see the behaviour of the engine check light, battery, oil, rev counter

Morning.
Video as requested

Rick

 

[pot51e]

Should be battery voltage

View attachment 457474

Here's mine tested, back probed

Take the pump out of the equation, should measure battery voltage disconnected

Finding a decent earth at the back isn't easy, the seatbelt bolt is about the only thing that isn't painted

Job done (better!) - yes, ~12v at the pump.

 

[koalar]

Job done (better!) - yes, ~12v at the pump.

Is that 12v disconnect or connected
Or is that from a better ground

 

[koalar]

Morning.
Video as requested

Rick

Everything looking good here

Body and dash and ECU all talking to each other, canbus between the three is also working for the rpm to display correctly

around 300 rpm is correct

Display not dimming or clock resetting

Earth and battery all look good

Not the normal 100hp display, usually 3 line and a white outer edge

 

[pot51e]

Is that 12v disconnect or connected
Or is that from a better ground

I did both TBF - got a good ground and disco'd as you advised.

Rick

 

[pot51e]

Everything looking good here

Body and dash and ECU all talking to each other, canbus between the three is also working for the rpm to display correctly

around 300 rpm is correct

Display not dimming or clock resetting

Earth and battery all look good

Not the normal 100hp display, usually 3 line and a white outer edge

View attachment 457502

Ah yes, my daughter swapped that out a couple of years ago - can't recall why.

Rick

 

[koalar]

Great 12v @ the pump, might have to test this again under load, relay and fuses don't need checking

Test the return to earth

Should be Red and purple, to the same ground point you used earlier, should be less than 1 ohm

Get someone to toggle the ignition on and off while tapping on the pump

You can do it from the top, here's me from underneath

 

[pot51e]

Morning!

Ok, so resistance measures at .6 ohm from the same good earth, to the red/purple.
Also tried a little light percussion on the fuel pump - no sign of life whatsoever.

Rick

 

[koalar]

.6 ohms is through the inertia switch so that's fine

Looks like it is the pump

Just check the feed does not drop when the connector is plugged due to high resistance

I take it the 6v early on was is a mistake