Fuel Economy Sensor - 190E 2.3 AT

[ralliart17]

gurus, quick question.. saan sensor nakakabit yung Fuel Economy meter sa instrument panel.. since umandar yung kotse, lagi syang nasa red, di sya gumagalaw. May this be causing the excess fuel consumption ng car?

Thanks!
Mark

[ghosthunter]

ever considered that the sensor could be faulty?

[ralliart17]

ever considered that the sensor could be faulty?

it was working kasi nung bago binaklas.. saka we're not sure kung san location nung sensor para dun...

[ghosthunter]

From what I know, the fuel economy gauge sensor might actually be a oil pressure sensor. Unfortunately I am no MB expert.

[Benzmizer]

I do remember experiencing the same on my 107 before. Found one of the "vacuum line" disconected at the engine bay. Sorry but I was not able to picture the part that was connected.... but it should something near the HVAC area.

Good luck!

[Benzmizer]

I do remember experiencing the same on my 107 before. Found one of the "vacuum line" disconected at the engine bay. Sorry but I was not able to picture the part that was connected.... but it should something near the HVAC area.

Good luck!

[mbeige]

gurus, quick question.. saan sensor nakakabit yung Fuel Economy meter sa instrument panel.. since umandar yung kotse, lagi syang nasa red, di sya gumagalaw. May this be causing the excess fuel consumption ng car?

Thanks!
Mark

The fuel economy gauge is a simple vacuum line routed to the intake manifold. It is a very rough estimate of your fuel economy. Maybe somebody routed it to a vacuum port that is always sucking air, or just plugged it off. I forgot if the system defaults to red when it's off or in the clear.

Regardless, I would find the vacuum hose and route it to the intake, near the brake booster. That's how it is in a 2.6, maybe the 2.3 is similar.

In principle, when you step on the gas, the intake manifold vacuum increases. So the economy gauge senses this and indicates the level of vacuum in the intake. The more vacuum, the more you are consuming fuel (since you're stepping more on the pedal). It's a glorified vacuum gauge. That's how it works.

[lowslowbenz]

What Pat said is correct .........

OR

Your air / fuel mixtures adjustments are way off spec...

[ralliart17]

What Pat said is correct .........

OR

Your air / fuel mixtures adjustments are way off spec...

I'll check the vacuum hoses..

and I might considering the second option... pag cold start kasi, ok ang idle ng kotse, asa 1K rpm then babagsak sa 750 pag naka aircon.. pag mainit na, sobrang baba na nya as 5K na and shaky na sya pag naka engage transmission..

[BJ71]

I'll check the vacuum hoses..

and I might considering the second option... pag cold start kasi, ok ang idle ng kotse, asa 1K rpm then babagsak sa 750 pag naka aircon.. pag mainit na, sobrang baba na nya as 5K na and shaky na sya pag naka engage transmission..

check mo rin yun ICV baka madumi o kaya nag loloko na

[mbeige]

I'll check the vacuum hoses..

and I might considering the second option... pag cold start kasi, ok ang idle ng kotse, asa 1K rpm then babagsak sa 750 pag naka aircon.. pag mainit na, sobrang baba na nya as 5K na and shaky na sya pag naka engage transmission..

Tama lang yan, 1,200RPM for 28 seconds pag start, bababa yan until 550RPM. Depende sa temperature ng makina yung RPM pag cold start. Cold start valve delivers more fuel sa cold start to warm it up faster. Then pagkatapos, patay na yung cold start valve once engine is okay na.

In earlier models WUR (warm up regulator) ang ginagamit. Similar function.

[ralliart17]

guys, quick update. Found the vacuum hose and it is connected to the intake manifold to the gauge... i can now see the fuel economy sensor moving.

bad news is, its always on the red zone of the meter.. have to have the engine tuned 'coz as mbeige suggested, the car's air/fuel mixtures are way out of spec, that why I'm only getting 5 km/liter..

Thanks..

[mbeige]

One of the other reasons your car could show bad fuel economy (via the gauge) is due to vacuum leaks. Since the gauge works by vacuum, any vacuum leak will translate to worse fuel economy.

The idle air control valve measures the air flow at idle and restricts it accordingly. This creates a vacuum. If there's a leak, it will manifest in the vacuum economy gauge.

When I pulled the IACV on my 2.6L to clean it, I accidentally cracked the vacuum lines (which are hard and brittle from age). Put them back and noticed better idling, but the economy gauge needle pointed more to the right (worse economy) due to the cracked line.

Start looking for vacuum leaks. If the vacuum leaks check out, then I would give it a full tune up. There is a way to adjust duty cycle PROPERLY and I emphasize this because there are specifications that these engines must adhere to. Otherwise, it will result in increased fuel consumption.