Technical Motor can’t start in the morning

[DK14]

Dear all,

This is about a Fiat 199, Grande Punto, 1,4 petrol. The year is 2006.

I have this challenge:

When I try to start the engine in the morning and engine is cold it makes motor failure and goes up to 1200rpm and then dies. After this the cooling fan will run in about 1 minute.

I first get failure on the MAP sensor and after the cooling sensor. Both parts are completely new.

Please see my photos, it seems that the MAP intake value is too high?

If I delete MAP failure before I start it normally start without problems.

Please help me. Thank you very much.

 

[jackwhoo]

Intake air temp looks wrong.
Anyone else looking note times on pics for engine run time between readings

 

[Rado77]

By my experience from other car brands it looks like coolant temp sensor. In case of it's failure ECU runs fan on 1st speed - but only when coolant sensor is disconnected, or has some electric/conne tor/wiring issue. I have no experiences with Fiat, maybe they dont use this "logic" and your sensor is completely ok...anyway - does this coolant sensor have 2 wires or 4 ?

 

[DK14]

By my experience from other car brands it looks like coolant temp sensor. In case of it's failure ECU runs fan on 1st speed - but only when coolant sensor is disconnected, or has some electric/conne tor/wiring issue. I have no experiences with Fiat, maybe they dont use this "logic" and your sensor is completely ok...anyway - does this coolant sensor have 2 wires or 4 ?

I remember 2 wires on the cooling sensor and 3 on the map sensor.

 

[GrandePunto PL]

... 1,4 petrol.

Which one? There are three (or more?): 8V, 16V Star-Jet, 16V T-Jet.

1. Get FES or MES program to read codes and parameters. Other "universal" programs don't work properly with Fiat cars. Just the way it is. Period.
2. MAP readings are rubbish, should be (non-turbo car) about +300 mbar (30 kPa) absolute (it's negative -0,7 bar if you like). So you have too much vacuum, numbers are too low, not "too high" (according to your current software, or MAP is shot - it is double sensor: pressure + temperature, both numbers wrong!).
Coolant looks OK (from 9 to 88 deg.C in 16 minutes).
3. If sensors (MAP + coolant) are brand new (and original, not cheap fakes, especially MAP), next thing is a wiring, connectors. Very last thing is ECU (then timing belt skip, restricted intake or opposite - leak)...
4. Other classic Grande problems, electrical. Like "earthing points" (Search this, there is a Guide too), weak alternator and/or battery. Worth checking. Year 2006? So you still have wrong style water drain (short?).

Lesson will be (probably): you don't throw a new sensors at the car just because error code says so.

 

[jackwhoo]

The timing advance degrees also look very wrong.

 

[GrandePunto PL]

Yes, weird numbers, probably 100% trash ("garbage in, garbage out" rule). He needs FES/MES, A.S.A.P.

Plus, real old-school diagnosis. Intake vacuum measurement with real mechanical gauge.
Almost no one does that anymore, even "professionals" (they read and erase codes and call it a "repair").

Example engine 1,4 8V. Needle flutter like that is acceptable. Good idle vacuum (-0,7 bar = 20 inHg = +300 mbar).

More in the Guides section: https://www.fiatforum.com/grande-pu...cuum-boost-gauge-m-jet-t-jet-2.html?p=4502458

 

[DGPunto]

+1 for MES: Link

 

[DK14]

Dear all,

First of all thank you for your help.

My challenge is now solved.

First I did big service on the car, the air filter was very old, and I had to remove the bolts with cutting grinder. After this I realized that the motor has a pressure sensor and a air pressure sensor, (danish words) and like i could read the pressure sensor is looking after the air degrees. I then replaced this with a Bosch sensor.

After this the car start without problems and drives like new. I normally drive Mercedes, and bought the Fiat like a second car while the S-class is in the body shop. I was thinking about selling the Fiat, but I don’t want, because its a very nice driving car.

Please see attached photos.