+1
Diagnostický případ
Opravené vozidlo
Stanislav Červený
Engine misfire
21.12.2017
412x
Informace o vozidle
| VIN: | TMBAA65J293190174 |
| Výrobce: | Skoda |
| Model: | Fabia II |
| Rok výroby: | 2006 |
| Kód motoru: | 1,2 |
| Typ motoru: | BBM |
| Výkon (kW): | 44 kW |
| Převodovka: | Manuální |
| Palivo: | Benzín |
| Najeto: | 120 000 km |
Jak se závada projevuje
Nefunguje / funguje nesprávně. After about 60 seconds from start the engine begins to misfire and after warming up it seems to be running almost all OK.
Jak často se závada projevuje
-
Sporadicky / za specifických podmínek.
- Za studena.
V jakém systému se závada vyskytuje
- Motoru.
- během jízdy
- [P0301] Cylinder #1 misfire detected - short to power
- trvalá závada
- sporadická závada
Doposud provedeno bez úspěchu
The vehicle arrived at our workshop to have the cylinder head valves repaired. This was diagnosed in another workshop. I wasn't completely convinced that the valves require repair.The fault symptom has been appearing about 1 year. The vehicle has been converted to LPG.
Tasks that I performed:
- Retrieve DTC memory
- Replace fuel filter (original)
- Replace spark plugs
- Replace ignition coil
- Fuel injectors tested (Jet-servis)
Tested cylinder pressure with compression meter - all cylinders with same pressure 13 bar. Measured MAP sensor signals, Lambda sensor signals, dynamic pressures, exhaust, fuel injectors, engine temperature, CKP/CMP synchronisation, secondary ignition.
Lot of values and information.
I focused my attention to the Lambda sensor. From the beginning the Lambda sensor recordings are showing shocks and fro this I concluded that there is a problem with the valves. After measuring dynamic exhaust pressure I not that sure if there is a valve problem or not.
Based on these findings I decided to disconnect the Lambda sensor and measure the sensor directly. The Lambda sensor is showing normal good values. While measuring the signal on pins 20 and 60 of the engine ECU I recorded impulses. With the Lambda sensor disconnnected the value is about 4V/10ms. When I reconnect the cold Lambda sensor the value is 1,5V/10ms. Once the Lambda sensor heats up and starts working the sensors signal merges with the impulses from the engine ECU.
Disconnecting the LPG system from the Lambda sensor didn't make a change.
This signal impuls seems to be triggering fault. I don't know how to continue.
