Hi.

Recently acquired cinq sporting (1.1) that hasn't been used for a long long time. No MOT history for 10+ years, even though it has been in this country since it was bought as new (only 69kkm on clock).
Only issue is that ours is stuttering (especially lower revs), doesn't want to rev that well and there is a bad loss of power.

So far we replaced plugs, leads, air filter, fuel filter and pump. Have done ECU reset several times. Lambda sensor was between 0.2 and 0.8V. Timing belt marks seem to line up. Engine light is off. Brakes are not engaged, clutch not slipping. All cylinders seem to be firing.
Nearby garage also checked for vacuum leaks and cleaned out intake - all seems good.

Noticed yesterday that if you start the engine then it feels really good for 3-5 seconds. Barely any stuttering and accelerates really well. But after those 5 seconds half of the horses leave the engine and it starts stuttering again.

Loss of power is so bad that acceleration from 0 to 100km/h is 25-35 seconds and top speed in 5th gear is around 100-110km/h.

Any ideas appreciated

You've gone all around the houses....check the two pole temp sensor against nominals

D

Thanks!

Any clues where do I find nominal values? Nothing mentioned about them in Haynes manual and didn't find anything from FAQ or Google.

Both the blue sensor mounted on intake and intake air temp sensor next to injector show 5000 ohm when cold (15C).
The one fitted on radiator doesn't show anything but I assume it works as a switch

E:
Blue sensor when hot is 250 ohm and sensor next to spark plug no 1 is 150 ohm. Didn't measure anything else.

Just left it at a garage to get cylinder compressions measured.

You searched too far from home

https://www.fiatforum.com/cinquecento-seicento/94737-cinq-sei-data.html

D

Very interesting.

That link you gave me says:

Coolant temp resistance (approx)
@ 0oC 10Kohms
@ 20oC 5Kohms
@60oC 10Kohms

Click to expand...

Assuming this is correct I plugged 10k ohm resistor into temp sensor connector to test it and it has been running much better and lots more torque, but acceleration still not what you expect and it still occasionally stutters a bit.

Received new temp sensor today only to find out that it is around 200 ohm at 90C just like old sensor.

Just acquired AutoData and according to them it is supposed to be 200 ohm at 90C.

So far I have replaced fuel filter and pump, spark plugs and leads, MAP sensor (helped a bit), coolant temp sensor, oxygen sensor and throttle position sensor, but still having issues.

No apparent vacuum leaks. All cylinders have same compression. ECU reset done.

Idles well, but no power at all. Barely takes off.

It helps somewhat (almost drivable in city) if I use 10k ohm resistor instead of blue coolant temperature sensor, but it still stutters quite heavily and lacks power.

For a few seconds after starting the car it goes like a rocket. And then issues begin.



Perhaps it isn't getting enough fuel? What more could be there to it?
Noticed that the breathing hose that connects to air box is under negative pressure (sucking air into top of the engine). Is it supposed to be like that?

That's perhaps supposed to say:

Coolant temp resistance (approx)
@60oC 1Kohms

IIRC, mine is about 3k5 at about 25°C.

My Cinq has obd plug at the ECU, maybe try and see what a diagnostics tells you.

Most of the time it's a puzzle, it can be anything, do the above will tell you what sensor is faulty (sometimes)

Check grounds, check fuses, check timing and the list goes on.

Fuel injector not working properly?

Exhaust silencer collapsed? This Doesn't sound very likely if it runs well for a few seconds though.

Thanks for ideas.
Planning to also measure fuel delivery rate and pressure too, maybe it is still fuel issue.

Can the timing even be wrong on Sporting? AutoData claims that you can't change it.

Fuel pressure was 0,2 bar. I'm surprised the car was still running.
Fuel pipe connected to fuel pump had come loose and it just fell off when opening hatch to tank. Fuel pressure is now 0,9 bar at idle.

Car runs much better now. No stuttering at all.
Acceleration from 0-100 km/h is 22 seconds though. Still something wrong or is this all I should expect from this little car?

Planning to take it to dyno. How much HP should I expect from wheel?

it should be a little quicker than that! just check its all in good condition. I found a collapsed rear exhaust silencer had a massive impact on performance.

Reset the ecu following the fuel problems and see if it improves things.

Exhaust has just been replaced as whole this year. Should be good. Still looks brand new from outside.

ECU reset was done. This is standard procedure already after changing something on the car

Has the car been modified at all?

Nothing that I know off.
Somebody has added old table leg as front strutbar so you never know what else they have tried to do.

Brought car to diagnostics for a quick look. They were quite puzzled (and laughing when I rolled in - Cinqs are really rare here, only 6 in whole country :slayer.
Going back on Tuesday and they will check it more thoroughly this time.

I'm starting to think that maybe exhaust is too restricted but not sure. Previous owner rebuilt it himself and bent pipes look quite narrow (maybe 2-3 cm diameter if I remember correctly).