Technical Panda 169 1.3 Multijet 70hp - Usually starts up when cold, rarely starts up when hot

[Rex97]

I have had my Panda for 3 weeks.
In the first week, we went for a drive for about an hour, parked up, turned the car off and it took a couple tries to start it again but there was no real alarming issue as we thought that maybe it was just having a funny 5 minutes and needed to reset for a bit. So after 5 minutes it started up no problem, didn't think too much of it but still kept it in mind.
I kept using the car as normal, even going shopping and parking up for 15 minutes and the car starting up, maybe cranking a little longer than usual but always starting.
12 minutes before my driving test this week, we had driven to the shop which was 5 minutes from the test centre, went into get a drink, came back out and the car wouldnt start again. But this time, it didnt start for 50 minutes and i failed to show up to my driving test (i know, what amazing timing for my car to pass out on me).
We managed to get it going again after 50 minutes and i drove home, when i got home i turned it off, tried to start it up again and there was nothing, not even turning over. Left it 6 hours and it started up perfectly.
I've had the crankshaft sensor changed, didnt fix the issue. I've had the battery checked, all fine. The starter motor isnt the problem from what we can see, it usually starts up perfectly when its not been driven. The grounds cables are all fine, no worries there. And the fuel pump is working.. but how far its getting to the engine is so far unknown as that's tomorrow's investigation. Whether its the injectors? not too sure.
ALSO theres no check engine lights and no error codes showing up on scanners so we're currently completely stuck. If we cant find anything tomorrow then its going to have to be a garage job.
Has anyone got ANY ideas on what it could be?

 

[koalar]

I’d be looking at the live data of the fuel pressure.

A worn high pressure pump struggle to maintain pressure when hot

 

[varesecrazy]

Hi

You said 'it didnt even turn over'

If turning the key doesnt turn the engine..

Thats relatively simple to investigate


The main black cable from Battery negative to gearbox and chassis...

They can break down internally
.. its a cheap thing to swap

 

[koalar]

Just like to confirm

Have we got one fault or two

We talk about cranking a little longer than normal to start from cold

And also

At one point not cranking

When hot and not starting are we talking about not cranking or not firing

 

[Rex97]

Hi

You said 'it didnt even turn over'

If turning the key doesnt turn the engine..

Thats relatively simple to investigate


The main black cable from Battery negative to gearbox and chassis...

They can break down internally
.. its a cheap thing to swap

I've had all my cables checked and they're all fine

 

[Rex97]

Just like to confirm

Have we got one fault or two

We talk about cranking a little longer than normal to start from cold

And also

At one point not cranking

When hot and not starting are we talking about not cranking or not firing

Its both haha. It basically starts when it wants to now but its more likely to not start when its been driven for a while. It will crank for a few attempts, then it will just click, all the electrics work, and the starter motor works but it doesnt do anything to the engine and then you leave it for 5 minutes and then the engine will attempt to start but not actually start and then out of the blue it'll start absolutely fine.

We checked the battery again last night and all the cables and everything is in working order with that, the starter motor is fine, but we've had a tip that it could be either EGR related or fuel injectors. My bf's Dad has worked on cars for years and he thinks its fuel related, whether it be a pipe blockage or something.

 

[Rex97]

I’d be looking at the live data of the fuel pressure.

A worn high pressure pump struggle to maintain pressure when hot

Yeah, we're thinking its more fuel related now. More tests on it today but its its a deeper job, its going to the garage

 

[koalar]

EGR leaking can cause difficult
Starting

I suspect from the symptoms a dodgy battery

If it’s not turning over fast enough the HP pump can’t produce enough pressure to atomise the fuel properly

Would fit with the click from the starter solenoid as well

Next time it fails try some jump leads from a running car

How to jump start a car in 9 steps | The AA

How to jump start a car step by step guide. Learn how to safely jump start a dead battery by using another car or a battery booster pack.

www.theaa.com

 

[Rex97]

EGR leaking can cause difficult
Starting

I suspect from the symptoms a dodgy battery

If it’s not turning over fast enough the HP pump can’t produce enough pressure to atomise the fuel properly

Would fit with the click from the starter solenoid as well

Next time it fails try some jump leads from a running car

View attachment 415521

How to jump start a car in 9 steps | The AA

How to jump start a car step by step guide. Learn how to safely jump start a dead battery by using another car or a battery booster pack.

www.theaa.com

EGR is something we were going to look into.
Battery is completely fine, we've tried using a running car and a jump pack to get the car going and it doesnt make any difference. Theres no extreme drops in volts and we've really tried the battery to show a fault but it just wont show anything alarming.

 

[koalar]

Jump leads from working car

Positive to positive

Negative to gear cable bracket

Would eliminate the gearbox ground

 

[koalar]

It will crank for a few attempts, then it will just click

Isn’t this pointing to a power problem ?

Unless you’ve been cranking for ages

 

[Rex97]

Jump leads from working car

Positive to positive

Negative to gear cable bracket

Would eliminate the gearbox ground

We've tested the grounds, no resistance. Visually looked fine, no corrosion, tested points with multimeter and ground were fine. Its either something to do with the EGR, or a fuel sensor or the fuel pump.. so far. It's so inconsistent that its hard to pin things on

 

[Rex97]

Isn’t this pointing to a power problem ?

We suspect the clicking from the starter motor is due to a slight voltage drop from continuously trying it so many times. We think If it was a power issue, it wouldn't crank and then not crank and then crank again and then be able to start every so often. Its not just cranking for a while and then stopping and then never cranking after that, its constantly changing between working and not working.

 

[koalar]

We've tested the grounds, no resistance. Visually looked fine, no corrosion, tested points with multimeter and ground were fine. Its either something to do with the EGR, or a fuel sensor or the fuel pump.. so far. It's so inconsistent that its hard to pin things on

You can’t check grounds for resistance ?

On hair of copper is 0 ohms but will not carry 100 amps

 

[Rex97]

You can’t check grounds for resistance ?

On hair of copper is 0 ohms but will not carry 100 amps

Right okay. The grounds look visually fine, what the best way to test them without resistance? - We've seen so many recommendations to test with resistance

 

[koalar]

We suspect the clicking from the starter motor is due to a slight voltage drop from continuously trying it so many times. We think If it was a power issue, it wouldn't crank and then not crank and then crank again and then be able to start every so often. Its not just cranking for a while and then stopping and then never cranking after that, its constantly changing between working and not working.

Not always

Batteries bounce back slightly

Starter turns over as low as 4.5V but will not start as below the 5V reference used by most of the sensors

 

[Rex97]

Not always

Batteries bounce back slightly

Starter turns over as low as 4.5V but will not start as below the 5V reference used by most of the sensors

We did have trouble with lights flickering in the car (dash lights and interior) a few times when we were attempting the start the car - would this be a symptom of a bad ground?

Is there a way to test it reliably or is it just to take it off and clean it or replace it?

 

[koalar]

Right okay. The grounds look visually fine, what the best way to test them without resistance? - We've seen so many recommendations to test with resistance

Voltage drop test

Google should find a good explication

However you have jump lead

On the fault car instead of putting the negative lead in the battery put it directly on the gearbox cable bracket

There’s an earth under the clutch slave cylinder that’s not visible

 

[koalar]

We did have trouble with lights flickering in the car (dash lights and interior) a few times when we were attempting the start the car - would this be a symptom of a bad ground?

Is there a way to test it reliably or is it just to take it off and clean it or replace it?

Yes
Or battery
Or terminals
Or alternator

 

[Rex97]

Voltage drop test

Google should find a good explication

However you have jump lead

On the fault car instead of putting the negative lead in the battery put it directly on the gearbox cable bracket

There’s an earth under the clutch slave cylinder that’s not visible

Pretty sure we did a volt drop test and showed no issues but we're just going to try another one just to be sure. Will report back.
If ground strap was the problem, wouldn't there be other symptoms once the car is running? Because ours runs and drives absolutely fine once started, no power drop when accelerating etc