Technical 1.28v very hard to start

[boguing]

Previously... It wasn't starting without a huge amount of cranking. I was chasing down a fuel relay fault logged in MES, think I sorted that, grubby connectors under the engine fuse panel. I thought that had cracked it, but the daughter says it's refusing to start again. The only other thing MES showed occasionally was a water temp sensor fault, but it would clear and not come back for months.

Getting ready to go up to her's and fix it on Sunday (oh yes, Father's Day) I'd appreciate suggestions. First thing I'll do is get MES on it, but let's make some guesses assuming that it's not the relay fault.

It's from cold.

It's intermittent.

There are sparks when it's refusing.

The plugs get damp.

Battery is new.

One thing I wondered. The water temp sensor happily displays water temp, but supposing it is glitchy, would that alter the cold start fuelling?

 

[chris3234]

Mains earth's and battery connection given a good clean
Corrosion in fuse box
Good
Any Roma shown when cranking ruling out bad crank sensor

 

[boguing]

Mains earth's and battery connection given a good clean
Corrosion in fuse box
Good
Any Roma shown when cranking ruling out bad crank sensor

Yes, all clean and it's spinning fast. Fuse box cleaner than the day it left Italy/Poland!

Roma?

 

[varesecrazy]

Roma?

Rotation..?

Does the Rev Counter climb as it cranks.. Good indicator of the crank (or cam..) sensor doing it's job

BUT, you have wet plugs..

So that suggests you have rotation forcing injection..?

What age is this 188 punto

Kit will probably be VERY close the the 169 panda

@koalar may well spot something obvious

 

[boguing]

Rotation..?

Does the Rev Counter climb as it cranks.. Good indicator of the crank (or cam..) sensor doing it's job

BUT, you have wet plugs..

So that suggests you have rotation forcing injection..?

What age is this 188 punto

Kit will probably be VERY close the the 169 panda

@koalar may well spot something obvious

That's a good question. I'll ask her to try it tomorrow. It's certainly showing correctly when it's running.

It's an '02.

(Funny you should mention the Panda similarity - I'll be going up in mine, and had already checked that they're the same to try swaps).

 

[koalar]

Not enough information to come to any definite conclusion without some further testing

If the fuel pump or relay was the cause, there would be no sound from the pump at ignition on

No crank sensor signal equals no spark, no fuel injectors, dry plugs

The wiring different on the Punto, I believe a faulty MAP sensor is common cause of bad starting and coolant P0115 errors

It's very likely if it also sometimes starts but idles lumpy and hard to rev, or cuts out without a bit of throttle

Live data should confirm it, coolant and air should be nearly identical give or take 5 degrees, and should be close to what Google says the temperature is where you are

Inlet manifold pressure should be close to what Google says the pressure to be, and should reduce while cranking


If it is only use a genuine Bosch, not a cheap china one with a fake Bosch label, second hand is normally fine, it's shared with a lot of cars just check the numbers on the top


Assuming the MAP is fine
Flooded see below for temporary fix
Plugs gap too big
Blocked Air filter
petrol vapour recovery system leaks
Fuel pressure
Timing
Compression
And so on


I don't know if the Punto has the same system to clear a flooded engine

On the Panda if you crank the engine with the throttle to the floor it cuts power to the injectors, worth a shot

 

[koalar]

Different car

But the principals are the same

And he explained it much better than me





Nice they aren't trying to make you buy there services

Almost make me want to use there services or recommend them

 

[portland_bill]

My Panda is also reluctant to start at times, more so the longer between uses. I think that the non-return valve in the pump is leaking back, reducing the pressure. If I turn on the ignition, wait for the pump to run its few seconds, turn off, turn on again, let the pump run a second time, it starts almost instantly.
I think my pump is old, and weak, and allowing the pressure to fall back. Attempts to test the fuel pressure have so far failed. There's a nice schrader valve in the fuel rail, but finding a pressure tester that will work on it is proving either difficult or expensive. Like a tyre valve, the pressure tester needs to depress the valve, but all the cheap testers I've seen require the valve to be removed. That's a faff. Remove valve, fit gauge, repressurise, leave, recheck.
Sykes Pickavant make one that will depress the valve, I think, but it is very expensive, for an occasional use tool.
I think MEs will report pressure, but of course needs ignition on, which will have run the pump. So more faff, removing the pump fuse or relay before checking.
If the injectors were leaking overnight, the fail to start would give flooding symptoms, which it does not if the 'double pump' procedure is used.

 

[boguing]

Not enough information to come to any definite conclusion without some further testing

If the fuel pump or relay was the cause, there would be no sound from the pump at ignition on

No crank sensor signal equals no spark, no fuel injectors, dry plugs

The wiring different on the Punto, I believe a faulty MAP sensor is common cause of bad starting and coolant P0115 errors

It's very likely if it also sometimes starts but idles lumpy and hard to rev, or cuts out without a bit of throttle

Live data should confirm it, coolant and air should be nearly identical give or take 5 degrees, and should be close to what Google says the temperature is where you are

Inlet manifold pressure should be close to what Google says the pressure to be, and should reduce while cranking


If it is only use a genuine Bosch, not a cheap china one with a fake Bosch label, second hand is normally fine, it's shared with a lot of cars just check the numbers on the top


Assuming the MAP is fine
Flooded see below for temporary fix
Plugs gap too big
Blocked Air filter
petrol vapour recovery system leaks
Fuel pressure
Timing
Compression
And so on


I don't know if the Punto has the same system to clear a flooded engine

On the Panda if you crank the engine with the throttle to the floor it cuts power to the injectors, worth a shot

Yes, throughout this saga the fuel pump always ran, and hopefully the poor connection was fixed by a good cleaning under the fuse box last time. I shall see tomorrow. (I ran it several times and no faults were logged).

I like the water/air temp mismatch theory a lot. The second to last time I looked at it everything seemed right (sparks and fuel) so I tipped some isopropyl alcohol down its neck and it started shortly afterwards. If that helped, and it wasn't coincidence, it does point at the fuelling being a bit wrong - not good enough to start but ok to run.

I've just been on the 'phone trying to buy both sensors ready for tomorrow, all closed bar EuroCarParts who haven't got any... I know I've got a water one somewhere, so hopefully will find that. Might do a bit of Panda/Punto parts swapping if not - and they're visually similar.

Failing that, I'm taking some brake cleaner, and that works way better than isopropyl.

 

[boguing]

My Panda is also reluctant to start at times, more so the longer between uses. I think that the non-return valve in the pump is leaking back, reducing the pressure. If I turn on the ignition, wait for the pump to run its few seconds, turn off, turn on again, let the pump run a second time, it starts almost instantly.
I think my pump is old, and weak, and allowing the pressure to fall back. Attempts to test the fuel pressure have so far failed. There's a nice schrader valve in the fuel rail, but finding a pressure tester that will work on it is proving either difficult or expensive. Like a tyre valve, the pressure tester needs to depress the valve, but all the cheap testers I've seen require the valve to be removed. That's a faff. Remove valve, fit gauge, repressurise, leave, recheck.
Sykes Pickavant make one that will depress the valve, I think, but it is very expensive, for an occasional use tool.
I think MEs will report pressure, but of course needs ignition on, which will have run the pump. So more faff, removing the pump fuse or relay before checking.
If the injectors were leaking overnight, the fail to start would give flooding symptoms, which it does not if the 'double pump' procedure is used.

That's certainly a possibility, but I think that the amount of cranking I've been doing would have given time to get fuel up from the tank. Easy enough to check with the relay out (I can now find it in my sleep), so thanks.

 

[koalar]

My car panda has a Punto Evo map sensor

Part numbers were identical

I don't know about the earlier Puntos

 

[boguing]

Feedback from The Girl.

Rev counter lifts to above zero on cranking. EML stays on.

Not the crank sensor then, but not much the wiser.

Just thinking about the 'old' problem of the fuel relay in case it's still logging that fault. What would the ecu do if it was convinced that no power was getting to the coil in the relay? No point in shutting it off, and if it really was a fault, why bother doing anything? It can't nurse an engine with no fuel going in. So is it just as it should be, a pointer to a genuine fault with no changing of anything else?

Or in this case, just ignore it because it's been a red herring the whole way through?

Oh and here's a thought. When it does finally start it's really rough and smoky for 20 seconds or so. If it was the fuel system suddenly working properly again it would just start like it would after running out of petrol.

Thinking out loud really, and kicking myself for not taking the water temp error more seriously. I'm actually looking forward to seeing the air and water temps!

 

[portland_bill]

Oh and here's a thought. When it does finally start it's really rough and smoky for 20 seconds or so. If it was the fuel system suddenly working properly again it would just start like it would after running out of petrol.

There have been issues on here with leaking injectors, which will dump fuel into the manifold, effectively giving an over rich startup. That could give roughness and smoke.
Some have tested this by removing the fuel rail, and placing the injectors, still attached and pressurised, into little jars, to see if they leak. Not sure of the timescale, but of course petrol will evaporate, and try to pretend it was never there.
Once mine fires, it runs sweetly, suggesting leaking injectors are not my issue.

 

[boguing]

It's a mystery.

A question about the rev counter. It doesn't show anything when it's spinning but not firing. When it fires it's fine. Is this normal, or does the ECU default to using the cam speed?

When I got here the red eml light would stay on after the other warnings had gone off. This is was engine off, ignition on. Is that normal?

Hooked up MES. No errors. Air and water temps correct.

Wouldn't start.

Squirt of brake cleaner, fired instantly. I had a look at all the parameters and they all seemed sensible. Still no errors.

 

[boguing]

I should add. This time, when it fired it ran perfectly, no smoke. I think that was probably because previously it was flooding from the repeated attempts.

 

[varesecrazy]

I think my pump is old, and weak, and allowing the pressure to fall back. Attempts to test the fuel pressure have so far failed. There's a nice schrader valve in the fuel rail, but finding a pressure tester that will work on it is proving either difficult or expensive. Like a tyre valve, the pressure tester needs to depress the valve, but all the cheap testers I've seen require the valve to be removed. That's a faff. Remove valve, fit gauge, repressurise, leave, recheck.
Sykes Pickavant make one that will depress the valve, I think, but it is very expensive, for an occasional use tool.

I probably no longer own this..

But I had a short "coupler", used to joint the 2 x double wheels on commercials


It's @150/200 mm long

And screws on.. Depressing the Schrader

Male end is another Schrader.. So That can have the innards removed

And be coupled up to your tester

Presumably these are so common they are inexpensive / disposable..?

 

[koalar]

It's a mystery.

A question about the rev counter. It doesn't show anything when it's spinning but not firing. When it fires it's fine. Is this normal, or does the ECU default to using the cam speed?

When I got here the red eml light would stay on after the other warnings had gone off. This is was engine off, ignition on. Is that normal?

Hooked up MES. No errors. Air and water temps correct.

Wouldn't start.

Squirt of brake cleaner, fired instantly. I had a look at all the parameters and they all seemed sensible. Still no errors.

No

Rev counter bumps up slightly while cranking

Unless the body computer is seeing less than 6.5V, clock will reset (Battery or ground)

Or no signal from the crank sensor

The engine computer will work down to just less than 5V and still report a RPM even when the BSI and dash can't

Here's mine cranking, start disabled

Here's mine with less than 6.5V, no rev counter

 

[koalar]

It's a mystery.

A question about the rev counter. It doesn't show anything when it's spinning but not firing. When it fires it's fine. Is this normal, or does the ECU default to using the cam speed?

When I got here the red eml light would stay on after the other warnings had gone off. This is was engine off, ignition on. Is that normal?

Hooked up MES. No errors. Air and water temps correct.

Wouldn't start.

Squirt of brake cleaner, fired instantly. I had a look at all the parameters and they all seemed sensible. Still no errors.

Did the oil and battery go out or stay on?

 

[boguing]

No

Rev counter bumps up slightly while cranking

Unless the body computer is seeing less than 6.5V, clock will reset (Battery or ground)

Or no signal from the crank sensor

The engine computer will work down to just less than 5V and still report a RPM even when the BSI and dash can't

Here's mine cranking, start disabled

View attachment 446550
View attachment 446551



Here's mine with less than 6.5V, no rev counter

View attachment 446552

Well, we're onto something then. What I don't understand then is that a) it shows revs when it's running, and b) that it's not logging a fault.

It's actually got (another) brand new battery in it. Connections all good and it spins nice and quickly. When I had MES up I did look at parameters and am pretty sure I looked at Volts, but only when it was running. (over 12, can't remember).

 

[boguing]

Did the oil and battery go out or stay on?

Stayed on.