Thread: Excessive fuel consumption

De-laminated intercooler hoses? Bob

Bob, if it was delaminated turbo hoses, wouldn't there be much more noticeable black smoke under load?
Stuffed MAF?

I recently changed my map sensor as it was showing all the right figures but the car was very underpowered, disconnected the maf and power came back. I've already replaced the maf, so dismissed this, and replaced the map sensor as I couldn't get it to show any higher boost, after upping the boost via the waste gate.
It has now more response and it doesn't smell rich at idle. I've also done the glow plugs, as they were shot also.
Just some thought for you, hopefully you get it nailed. I've worked out the the nanocom isn't fail safe.

Cheers
Bronson

injector harness even if you dont have oil at the ecu.
Restored my fuel economy when I replaced...
Regards

Hi
Check waste gate is not seized. Have a TD5 130 which did just what you have described. Fixed it up and adjusted boost to 18 psi, now goes like a dream and fuel economy now OK. My drama now is after NT trip culling camels the GB is noisy and fuel pump squealing (Dealer said maybe watered down fuel).
Ah well, first problem since new (2002) 3 to 4 k cost.

Originally Posted by Disco Muppet

Bob, if it was delaminated turbo hoses, wouldn't there be much more noticeable black smoke under load?
Stuffed MAF?

If they were completely stuffed, yes, but what if the inside was just starting to come away, would it be possible to create these symptoms? I don't know, of course, but just a thought. Bob

Check your maf figures on nanocom. Compare with others. What brand maf did you fit previously. Cheap??? Or good one? Can make all the difference to fuel consumption.

Let's not forget that Nanocoms (and Hawkeyes, Faultmates, etc) are tools, and like all tools depend on the skill and knowledge of the user.

Simply because the Nanocom is showing numbers you can't assume that they are "correct". For example how can you tell if a MAP sensor is showing "all the right numbers" if you don't have another reference - like an accurate boost gauge connected close to the same point as the MAP sensor - to check against?

You also need to consider how the sensor works and how the ECU uses sensor data. MAP/IAT isn't just a boost sensor - both the Intake Temperature and the Manifold Pressure are used to determine the density of the air in the intake manifold, and this is used as a key input in determining how the engine is fuelled.

It's worth thinking about how you can cross check sensors. For the MAP you can try unbolting the MAP from the manifold and checking the output in free air. Compare that reading with the Ambient Pressure reading from the airbox - they should be very close to each other. While you have the map sensor removed (but still connected to the harness) check the intake temp. reading against a digital thermometer. Again they should be within a degree or two.

If you can clean the MAP/IAT but avoid poking things into holes. There is a small opening on the back of the sensor that is used to measure ambient pressure. It's worth checking to sure make this isn't obstructed with gunge.

cheers
Paul