Very High Fuel Consumption

**wheelspin** · 28th October 2022, 17:36

Guys,

Note been on here for some time as all things have been good. However, the car is a Vectra C Estate 1.9CDTI with a very high fuel consumption. To give an idea I've just done 89 miles on £40 of motion lotion. Now a few things have happened which may lead to the root of the problem, but I need some expert advice to narrow down the problem.
1 The turbo was refurbished by Telford Turbo's and runs just fine. It was done because it was passing a lot of oil.
2 At the same time as doing the turbo I cleaned out the throttle body that was full of oil. Then noticed the wires leading to the throttle body had perished so cut out the bad wire soldered, and heat shrunk to make a good job. Expected to get a management light on but no all was good.
So, I used the usual software to operate the throttle and the flap moved, however when I look at the position of the flap the feedback doesn't change. So, does the ECU use this feedback for metering air/fuel ratio ?
Hope you guys can help.

**northpole** · 29th October 2022, 09:22

i'd be checking what the state of the MAP sensor is, as you didn't state you've cleaned it.

**wheelspin** · 29th October 2022, 17:00

Originally Posted by northpole

i'd be checking what the state of the MAP sensor is, as you didn't state you've cleaned it.

Thanks for the reply, so checked it this afternoon and to be honest it was cleaner than I expected it to be. Give it a blast with some carb cleaner to remove the oil mist on it and replaced it.

**northpole** · 29th October 2022, 19:36

Did it solve the problem though?

**wheelspin** · 23rd November 2022, 21:50

No, it hasn't made any difference to the fuel consumption.

**northpole** · 24th November 2022, 09:06

oke so we are going to need some extra information:
have you blanked the egr?
have you removed the intake flaps?
is your exhaust smoking, and if so what is the colour of the smoke?
when did you change the fuel filter?
what size wheels are you running and what's the tire pressure ?
what is the state of the rear calipers and disks?

**finn67** · 24th November 2022, 10:44

Your mileage to fuel ratio suggests one thing only, there's diesel leaking somewhere between the tank and the injectors. You'll need a second person here ... Pop the bonnet - remove big plastics to give you a better view ... engine idling ... scour the bay area for any diesel anywhere outside of piping or filter --- nothing? ask your assistant to take it to about 2,000 revs - then 3,000 ... by now, if you have a leak from the injector/seal or leak off pipes then you will be seeing it now. It may only be a small splash at the minute but under torque load driving it could be pouring out ...

**wheelspin** · 3rd December 2022, 01:18

Response in blue.

Originally Posted by northpole

oke so we are going to need some extra information:
have you blanked the egr?Yes, and it's mapped out
have you removed the intake flaps? No
is your exhaust smoking, and if so what is the colour of the smoke No
when did you change the fuel filter? 9 Months ago
what size wheels are you running and what's the tire pressure 17" and 36Psi
what is the state of the rear calipers and disks? Good condition

**wheelspin** · 3rd December 2022, 01:22

Originally Posted by finn67

Your mileage to fuel ratio suggests one thing only, there's diesel leaking somewhere between the tank and the injectors. You'll need a second person here ... Pop the bonnet - remove big plastics to give you a better view ... engine idling ... scour the bay area for any diesel anywhere outside of piping or filter --- nothing? ask your assistant to take it to about 2,000 revs - then 3,000 ... by now, if you have a leak from the injector/seal or leak off pipes then you will be seeing it now. It may only be a small splash at the minute but under torque load driving it could be pouring out ...

I thought about that some weeks ago before posting on here but couldn't find a single leak anywhere or even smell diesel. I'm baffled because this only started after re-fitting the turbo from being re-cored.

**wheelspin** · 3rd December 2022, 01:29

Originally Posted by finn67

Your mileage to fuel ratio suggests one thing only, there's diesel leaking somewhere between the tank and the injectors. You'll need a second person here ... Pop the bonnet - remove big plastics to give you a better view ... engine idling ... scour the bay area for any diesel anywhere outside of piping or filter --- nothing? ask your assistant to take it to about 2,000 revs - then 3,000 ... by now, if you have a leak from the injector/seal or leak off pipes then you will be seeing it now. It may only be a small splash at the minute but under torque load driving it could be pouring out ...

<br><br>I thought about that some weeks ago before posting on here but couldn't find a single leak anywhere or even smell diesel. I'm baffled because this only started after re-fitting the turbo from being re-cored.<br>
<br>