Excessive fuel consumption

paddle · 14-10-2006, 11:31 PM

I have recently been having massive fuel consumption issues and a bad smell coming from the exhaust on my au1.
Yesterday I installed a brand new oxygen sensor (bosh) as I have heard they can be a problem after 80thou, IT WAS CHARCOAL and my spark plugs where the same,so I replaced the lot and also did the fuel filter while I was at it.
I reset the ecu and went for a nice drive,followed the procedure on a previous thread and thought all would be fine.
My mate took it to work this morning,Cranbourne to Port Melbourne and back so everything should be set right by now.
I put $40 fuel in it later that day,DTO said 308k to empty,got home turned car off at 305,turn car on later,it was down to 296,bottom line is i'm always "losing" fuel when I stop the car,then I go back later to have lost on average 6-10 ks per trip??,then whilst driving I can watch the DTO count down like a stopwatch!,keeps getting lower,it adds up after a while cause it now gets to just under 30k left and is out of fuel,I have replaced everything that I can think of,except the map sensor,where is it, what is it and can it be cleaned?
any pics would be nice as I don't even know what im looking for!
Im lucky to get 20k to $10 atm,
Is there anything else i may have missed?
I am at wits end,she is getting too expensive,any ideas what is wrong?
sorry for such a long post!

XEESP_351 · 14-10-2006, 11:41 PM

so running real rich?

XEESP_351 · 14-10-2006, 11:44 PM

possibly coolant temp sesnsor faulty which is located in lower thermostat housing, assuming I6
If was map sensor it would be running really rough too

JoesAu · 14-10-2006, 11:51 PM

it sounds pretty bad. My car usally drop 10km's on idle on the DTO, i think its normal cos it counts ahead wen u top it up with fuel and start it, then wen u turn it off then start it again it knows exactly how much it really has in the tank and u get an accurate reading on the DTO, my car has always done it ive never worried about it. Make sure all your vacuum lines are connected, fuel filter is correctly on. Hav u got a aftermarket exhaust cos i know the smell u have cos my car does it too it stinks bad, even with the stock exhaust it stunk. The car is running way rich take it in and get it analyzed on a dyno thats what im planning it will tell u your problems, I got 425km's out of a tank a month ago.

paddle · 14-10-2006, 11:57 PM

Quote:

Originally Posted by mr t-series

possibly coolant temp sesnsor faulty which is located in lower thermostat housing, assuming I6
If was map sensor it would be running really rough too

where do I find that and is it expensive? Could that be a reason my car is running cold too?
I have just replaced the thermostat (genuine) and coolant (nulon) and still seems to sit on the N bit of NORMAL

JoesAu · 15-10-2006, 12:01 AM

N bit is where they run perfect spot on. unless its a 40 degree day it will move slightly, and if ur getting up it it mite move a little.

XEESP_351 · 15-10-2006, 12:10 AM

unsure of price shouldnt be dear just a sensor
It screws into the lower thermostat housing located at the front of the engine on the inlet side
i think it does control temp gauge too
Wot it does is it sends coolant temp to ECU to help adjust fuel mixture (lean or rich) (as do a few other senses) when engine running. If it senses that the engine is cold all the time it will sentd a rich signal to ECU. ITs there for start up to give more fuel to run properly when cold, like a choke does on a carburetter.
Any good parts stores should have 1 id recomend REPCO on a sunday
Should really take it to mechanic that has an exhaust gas anyliser they will tell u for sure

TwistedEL · 15-10-2006, 12:28 AM

If the temp guage is in the normal range you can rule out coolant sensor.
The DTE isn't gospel, it averages and will go up & down depending on driving conditions.

20k to $10 that is like 160k's / tank? You have a fuel leak my friend if that is the case.

XEESP_351 · 15-10-2006, 12:46 AM

does it blow black or grey smoke when u rev it?

rag top · 15-10-2006, 08:02 AM

What condition is the catalytic converter in???

Casper · 15-10-2006, 08:15 AM

Quote:

Originally Posted by paddle

I have replaced everything that I can think of,except the map sensor,where is it, what is it and can it be cleaned?

The MAP sensor is located under the throttle body. In laymans terms, where the intake pipe joins the manifold, look under that.. there is a little black box screwed into it. It is not a cleanable item, they are about $150 to buy.

Quote:

Originally Posted by mr t-series

If was map sensor it would be running really rough too

No, it wouldnt. It would simply run rich. If the MAP sensoor dies the ECU goes into "default" mode and runs very rich, the actual 'feel' is simply a loss of power but the engine will remain as smooth as it ever was.

paddle · 15-10-2006, 12:43 PM

Quote:

Originally Posted by TwistedEL

If the temp guage is in the normal range you can rule out coolant sensor.
The DTE isn't gospel, it averages and will go up & down depending on driving conditions.

20k to $10 that is like 160k's / tank? You have a fuel leak my friend if that is the case.

I guess that rules that out as you said,no apparrant fuel leaks either,checked and rechecked the lines/fuel filter,all good.

paddle · 15-10-2006, 12:50 PM

Quote:

Originally Posted by mr t-series

does it blow black or grey smoke when u rev it?

was blowing black smoke till I changed the o2 sensor,still puffs a mixture of black/grey then it lightens up a biit with a hard "double" rev to 6thou a small backfire then greyer smoke (if that makes sense to you) but exhaust can still smell bad at times

Bill_R · 15-10-2006, 01:00 PM

the smell is like sulphur?
the smell indicates a really bad tune that, as you know, might indicate something is way out of whack. A reply here makes mention of your Cat - it might be stuffed now but eh cause really needs addressing.
systematically work your way through - check on simple things such as the air intake, filter etc first. reset the ECU and see if a difference is made - it could have spiked or it could be damaged.

Bill_R · 15-10-2006, 01:02 PM

Quote:

Originally Posted by Bill_R

the smell is like sulphur?
the smell indicates a really bad tune that, as you know, might indicate something is way out of whack. A reply here makes mention of your Cat - it might be stuffed now but eh cause really needs addressing.
systematically work your way through - check on simple things such as the air intake, filter etc first. reset the ECU and see if a difference is made - it could have spiked or it could be damaged.

woops, noticed right now you reset the ECU.