Changement pompe à injection 850 tdi - régime moteur instable- Suite

[hioub]

allez, on redéterre!!!!

[hioub]

Bonjour,
je me permets de redéterrer.....

[hioub]

un peu de lecture, suis à la découverte de mon code erreur efi 717 sur mon break:


I have 11/1996 Volvo 850 TDI. Bought it back in 3/2004, so I'm the owner for almost 12 years.

First time I got "EFI 716 Quantity of fuel signal" error code was in 9/2013. It appeared after experiencing very rough rattling idle, and rough driving at slower speeds up to 40-50 km/h. Must add that it was strange that it took 2-3 days of such symptoms before the CE light lit up. It never stalled.

Google suggested to check the cables and connectors first. I had no knowledge about the fuel pump connectors at the time, so I disconnected only the 3 pin connector I could see and reach (I was away on holidays on a small remote island at the time so I had limited access to everything).

The idea was to disconnect and reconnect it repeatedly to scratch the metal pins inside and then I dried it with some paper and finally left it overnight to dry cause the area around was dirty and greasy or oily.

I connected it the next day and everything was fine! And it lasted for about six months. All in all it happened 4 times in the last 3 years, but I was never 100% sure, cause I had the car in the shop and besides cleaning that 3 pin connector they also cleaned few other connectors.

The 4th time it happened was 2 months ago, I was on holidays again, and also I had reconditioned the MAF before that, so while on the island, I was not sure what to blame...

Came back home and did some research on the pump connectors to see if I can find the link between the rough idle and the pins (signals) on the connectors.

So, there are 2 cables/connectors on the pump. One is the 7 pin, and the other is the 3 pin I am writing about. I found that one of the three pins is a power supply fot the "Fuel Shutoff valve (solenoid)", and the other two control the "Solenoid valve for start-of-injection timing".

So first I disconnected the 3 pin connector and sprayed it with proper contact cleaner and left it overnight. It improved, but it wasn't good. Then the following weekend when I had enough time, I checked it again and found it to be wet, probably it did not dry enough overnight. So this time I cleaned it and dried it very thoroughly.

That rigorous cleaning and drying was a month ago, and since then I drove more than 2.200 kms and everything is fine without the symptoms whatsoever!!! :-)

Hope it helps.