Hi Guys. Over the past month or so my ecotec has developed a shocking ping when accelerating. So far I have changed the fuel pump, filter, oil, coil packs (had a spare set) and nothing has helped. The car is always run on BP Ultimate and has been tuned for it. Anyone got any other ideas? I was thinking it could be injectors but really can't afford to swap them at the moment. Thanks
Id start by following the above suggestion,refitting the proper memcal.Also check the knock sensors,their wiring and connectors,check to make sure the wiring is still connected to the sensors on each side of the engine.Id also check the ECU error codes to see if the knock sensors have set an error code,or if any other problems have set any codes.If you are not sure how to check for these error codes,then just check out the link below,its easy to do,theres also some good pics showing how to do the test,these pics are down near the bottom of the posts in the link. ---http://forums.justcommodores.com.au/holden-commodore-how-tos/22307-checking-error-codes-vr-vs-revised.html---
Mine does the same and ive done everything listed other then changed the injectors, Finding this prob may become Must no info for the ecotec driver.
Knock sensors most likely, as the computer winds the timing right up until a knock is detected but even if the computer brings the timing right back red hot carbon can pre-ignite the fuel, carbon build ups are common in higher mileage engine that are using abit of oil.
This is not entirely correct. The EcoTech ignition map has two tables, normal and knock. When knock is detected via the sensors the ignition jumps to the slightly retarded no knock table, once all is OK it jumps back to the normal table. I will not advance the timing above the preset no knock table. Also, the DFI controls timing up to around 1500rpm (IIRC) then 'hands over' timing to the PCM. As above, restore it to standard then go from there with a fault code check.
I have restored the original memcal & run a code check and nothing. All signs are looking at the knock sensor.
Run Techron 5000 injector cleaner in the fuel tank. Let the fuel tank run down until the fuel light comes on (approx around 15 Litres left) Go to Caltex add the Techron 5000 injector cleaner and fill with 25 Litres of 95 RON so that you have around 40 Litres so you don'y dilute is strenght. Run it until the fuel light comes back and then refill with Caltex. This is not promotion for Caltex. Its just the Techron in the fuel is a very good cleaner and has proven results in cases similiar to this. Techron 5000 is around $12 for 350ml from a Caltex Service Station.
You could try the above suggestion, but the only real way to eliminate the injectors is to remove them. Get them flow tested, cleaned and re flow tested when they are out.
