Strange Drop In Fuel Economy?

[agnesx]

i can't believe my string of bad luck this month with my car...

aside from car park incident, now i have to deal with a dodgey mechanic...

long story short, my car (gen 1 seo) has been running fine for the last 2 years i have had it, always running premium fuel (Shell optimax) and usually giving me 13km/ltr

few weeks ago i tried a new mechanic near my new work location, they recommended an EFI clean to improve my fuel economy further as it seemed to be blocked a bit... so i paid the $200 to get it cleaned...

when i went to pick it up, not only did they tell me they had accidentally set fire to my engine bay for 10sec, they have left all this white powder from an extinguisher all over it.

ever since, my car has lost lots on economy, i am only getting 9km/ltr now and they argue with me and tell me **** like its due to a small leak from my gasket manifold (which is so small the leak is 0.005ml/day, and i have had this crack from day 1)

every other reason they gave me i had a rebuttal, as all those problems they blamed on I had rectified recently without further problem... they deny that they have ****** up and not willing to return my car to its original status unless i pay them another $200 for them to inspect and fix any other problems....

I was wondering... can anyone gimme a clue as to what could have caused this sudden huge drop in my fuel economy? could it be the fire they set damaged parts of the internals? could it be the uncleaned powder from the extinguisher doing some harm?

I have a feeling the air filters would be blocked as ****, and will replace it tmr when i have time to locate a K&N filter...

btw, the car idles at 1,200 now and runs way too rich, i can smell the petrol from inside my car... and i know that can't be good....

please give me some ideas so i can have a look myself to fix this....

on btw the dodgey place for anyone living in VIC Australia is

Ultratune Glen Waverley, operated by two dodgey mechanics called Sam and Roger

Avoid at all costs....

[nrgizerbunny]

well here's my thought process.

1. car is running okay but too ruch, therefore injectors are working okay

2. fire in the engine bay - probably torched some wiring

3. fire extinguisher powder - probably coated the air filter.

I'd say either one of the following, the air temp/pressure sensor is broken or the wiring from it is screwed or the ECU has something wrong with it (although the latter is unlikely as its well protected).

it sounds like the engine thinks its getting more air than it actually is, hence the rich mixture. hope this helps, good luck

[toyotasera.co.uk]

What is your water temp gauge doing? Often a problem with a sudden increase in fuel consumption is due to the thermostat failing open, causing the coolant to take ages to warm up, confusing the engine into thinking its still on the cold start mode...

[VTRick]

yeah, check what andrew said, this happened to my glanza

[riko666]

someone set your engine on fire too ?!?!?!?

:P

[agnesx]

thanks for all the advice guys, that's really appreciated and helpful,

“What is your water temp gauge doing?” I am not sure if you mean the thermostat in my radiator? That was found faulty about 3 mths ago and I got a new working one back then… could be failed again? This I cannot check myself but will ask my usual mechanic to have a look for me

“1. car is running okay but too rich, therefore injectors are working okay” phew, that’s always good to start

“2. fire in the engine bay - probably torched some wiring” could this damage be severe enough to effect anything significantly?

“3. fire extinguisher powder - probably coated the air filter.” Ordering a K&N filter as I am typing this, could I check if the part number is right? For a gen 1 seo

33-2094 - its of a rectangular shape

http://www.knfilters.com/search/product.aspx?Prod=33-2094

thanks again guys

[nrgizerbunny]

by water temp thing, have a look at the engine temperature gauge, if the needle is not in the middle (90C) when the car is hot then likelihood is the thermostat is screwed.

you don't need a mechanic to check that.

[toyotasera.co.uk]

and the car should get to halfway up the gauge within 5 minutes or 5 miles from cold.

[agnesx]

yeah the engine heats up fine, the needle is ~90 degrees within 5~7min

I have some fuel measurement numbers here after the fire

When cold

CO = 11.287%vol

HC = 959 ppm

CO2 = 7.50%vol

O2 = 0.52%vol

Air/Fuel ratio = 10.1:1

when engine is running and hot

CO = 2.664%vol

HC = 353 ppm

CO2 = 13.77%vol

O2 = 0.00%vol

Air/Fuel ratio = 13.4:1

i recognise all these gases and roughly know what they mean... but since i didn't get the paseo manual with my car... what is the 'normal' numbers for these factors under both conditions?

and when they tested these numbers, the dodgey mechanics ran my car for a while without the (clogged) filter... now isn't that bad for my engine? if something got sucked in would it damage the insides of the engine?