Technical Clutch issues - what needs to be fixed/replaced?

[YellowPuntoFiat]

Hi, my son took his car out today and the following issue occurred: when at a stop light, releasing (lifting the clutch pedal) the clutch stalls the engine.

This is something new, but I will provide a bit of a backstory. First off, I always thought that his clutch pedal engage very low to the floor. So you had to lift your foot very little for the gears to engage. However, he told me this was always how his clutch worked. He has owned the car for over 2 years now. Never had a clutch issue. However, about a month ago, he did have an accident in the parking lot where somebody drove into his front driver side wheel. We had to replace the inner and outer tie rods because of that (details can be read here: https://www.fiatforum.com/threads/wheel-alignment-knocked-out-by-accident.520520/page-2#post-4845117 ). Due to the need to wait for insurance and parts, the car has been sitting for that time period.

So my question to you is what needs to be fixed and or replaced?

Should I get a cluctch kit? Or is it potentially something else related to the hydraulics? There is no problem getting it into gear or driving. Just when the clutch is released the engine stalls.

Thanks for your help.

 

[GrandePunto PL]

We don't see the car. You must find out what's wrong.
It could be a clutch wear (it is not releasing smoothly) or something simple like a clutch pedal switch.
So, fault is electrical (signal), not mechanical/hydraulic.

 

[YellowPuntoFiat]

Would something like that show up on the OBD reader?
What kind of tests can I do to troubleshoot potential issues?

 

[jackwhoo]

Do you mean that the engine stops if clutch pedal released with gearbox in neutral?

 

[AnthonyH]

Hi, my son took his car out today and the following issue occurred: when at a stop light, releasing (lifting the clutch pedal) the clutch stalls the engine.

This is something new, but I will provide a bit of a backstory. First off, I always thought that his clutch pedal engage very low to the floor. So you had to lift your foot very little for the gears to engage. However, he told me this was always how his clutch worked. He has owned the car for over 2 years now. Never had a clutch issue. However, about a month ago, he did have an accident in the parking lot where somebody drove into his front driver side wheel. We had to replace the inner and outer tie rods because of that (details can be read here: https://www.fiatforum.com/threads/wheel-alignment-knocked-out-by-accident.520520/page-2#post-4845117 ). Due to the need to wait for insurance and parts, the car has been sitting for that time period.

So my question to you is what needs to be fixed and or replaced?

Should I get a cluctch kit? Or is it potentially something else related to the hydraulics? There is no problem getting it into gear or driving. Just when the clutch is released the engine stalls.

Thanks for your help.

Have you checked for leaks? has your son ever topped up the brake fluid reservoir? Is the level ok?

It could be the master cylinder, or the clutch.

 

[bugsymike]

Can you answer some of the queries posed by Forum Members to help guide diagnosis.

 

[Mike1alike]

So you had to lift your foot very little for the gears to engage. However, he told me this was always how his clutch worked. He has owned the car for over 2 years now.

Yeah, that is not normal. The fact that he drove it more than 2 years with that problem didn't fixed it and it doesn't mean it's not a problem.
Considering that he could drive it so long like that, I say the clutch cylinder/system was not bleeded or not completely anyway. There is air in the system.
And now, on top of that there is another problem. Probably the master cylinder is worn out, especially because it was used like that. But they do wear out anyway, sooner or later. It's just much better to have it working without air in the system.

 

[Mike1alike]

or something simple like a clutch pedal switch.
So, fault is electrical (signal), not mechanical/hydraulic.

Does it have a clutch pedal switch?

 

[bugsymike]

As @Mike1alike mentions, the clutch master cylinder may be worth checking.
Often they will appear to work, but if pedal held down with car in gear the hydraulics start to relax their pressure so car can stall at junctions etc.
In the old days brake master cylinders would do that, where if you slammed the brake on hard it would work perfectly, but if you pressed it gently the pedal would gradually go down to the floor, which with single circuit brakes was quite frightening.

 

[jackwhoo]

Stationary at stop light " just when the clutch is Released the the engine stalls"

Yep unless the transmission is in neutral that will happen
If transmission in neutral it should not happen

To me this does not currently read as a clutch issue

 

[YellowPuntoFiat]

Hi, update and hopefully will answer some of the questions from members.
The OBD didn't show anything.

To answer @jackwhoo - it happens at stop lights but also while driving. So for example, if he was driving and let the car drift in neutral with the clutch pedal up, it would also stall the engine.

Haven't checked for leaks. Where should I be looking? I don't think that he has ever topped up the brake fluid. But we can also check whether this is at the correct level. @AnthonyH - the master cylinder is the break one right? Or is there a clutch one too?

Probably has a clutch switch (but need to check) based on the year. Looking at a few YouTube videos it looks like these models should have a clutch switch.

Will look into some these things and go for test drive today. Will come back with updates.

 

[bugsymike]

If stalling in neutral surely an engine issue?

 

[jackwhoo]

Its not a clutch issue.

Drift into neutral with clutch pedal up....
@portland_bill may have something to say

 

[jackwhoo]

Does this car have stop start system ?

 

[bugsymike]

I had something similar with a 21014 Vauxhall Combo 1.3 MJ (Doblo in drag) and it was a tag broken off the clutch pedal position sensor although before and after fitted the Stop/Start function was in/op.
Note, it did show up with diagnostics.

 

[jackwhoo]

Do not coast with car in neutral.
Do not drive with hand resting on gear (shift)lever....hand on lever only when changing(shifting).

 

[Mike1alike]

the master cylinder is the break one right? Or is there a clutch one too?

No. There is a clutch master cylinder, has nothing to do with break one, they just share the fluid reservoir.
The clutch master cylinder is connected under clutch pedal. Pedal pushes it in and the servo force pushes out at the other end the slave cylinder and that presses the clutch to release the grip.

 

[jackwhoo]

Engine stopping is not a clutch issue

 

[Mike1alike]

Probably the idle air control valve is the problem (or the throttle body/sensor if the TB is fly-by wired, not cable operated).
Could also be clogged injectors.

 

[GrandePunto PL]

No such thing from the Grande model and above (Evo, 2012 lift). IAC valve was in the Punto_2 and older generations.
Unless the throttle body is mechanically damaged (it's sticky, has broken plastic gears inside), you don't mess with it.

To check it (full range movement, if it "sticks", lags), you mimic the compression test: just remove the fuel pump relay and put the key in the ignition ready position, then the ECU will move the flap when you step on the "gas" (normally it doesn't move).

Diagnosis path is obvious. There is no "mystery" faults.
1. Schematic diagrams (links are for Grande, but Evo/2012 should be the same or very close, 99% match).
Check all "sensors": brake and clutch pedal switch + gearbox neutral switch ("sensor") if there's a Start&Stop.
ECU will use all of those to alter the engine parameters, but in case of fault it can stall the engine.
You can monitor those signals in the OBD (FES, MES or AlfaOBD programs), but real, physical, hardware check is always preferred.

ECU wiring (brake and clutch switches are elements I030 and I031).
https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199018470&languageID=2&markID=1&modelID=199000000&valID=199000001&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Impianto Elettrico&validityName=1.4 8v

Start-Stop system (neutral position switch is K214, there is also a brake servo vacuum switch K105 to check + the actual intake vacuum ≈ 300 mbar idle).
https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199018425&languageID=2&markID=1&modelID=199000000&valID=199000001&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Impianto Elettrico&validityName=1.4 8v

Note, that neutral switch (K214) shares the 5V power supply with a gas (accelerator) pedal (K055) and the A/C system pressure transducer (K120)!
So, fault of one of those (or the wiring) can spoil the remaining two circuits/systems.

2. Hydraulics? No problem (to rule out the clutch). You check the clutch pressure (expect about 20-25 bar) using 3-way connector and thread adapter (from M10x1 to the gauge, metric or pipe, like 1/4" or so). And see if the system holds it or it drops (means there's a leak, external/internal).

Pressure gauge is often not enough. But you can grab the pressure waveform using A/C system and same type of transducer. But custom adapter is required.
That way you can see if the clutch is releasing smoothly or rapidly (like in the video below, there is a harsh step, drop - you can NOT see it on the gauge or feel under your feet, but the car is jerking, sometimes even doing burnouts...or almost stalling).


3. Other things like fuel, ignition, timing. And maintenance like valve clearance (all 8V petrol engines). It (bad valve lash) can stall the engine too.

Combinations of points 1-2-3 are possible too (little bit of everything: bad brake/clutch sensor, weak clutch master - internal leak, valves never adjusted).