Corolla 1.3gli Idle Speed And Fuel Probs!

November 8, 2007

Hi all,

im new here so be nice!

I have a 1993 Toyota Corolla 1.3 GLi 16v, with 85,000 miles on the clock (nice and low !)

But i am finding the idle speed a bit too fast. When cold it idles around 1200-1400rpm which is fine if the engine is cold, you would expect it to be high in order to warm it up and get it going!

But the idle speed doesn't change even when it has warmed up! I drove about 100 miles yesterday and it idled between 1200-1800rpm at the beggining, middle and end of the journey!

Also the fuel consumtion is worse than my 1.8cc renault! Do you think the high idle speed is causing the excessive fuel consumption?

How can i solve this problem? I am no expert at mechanics but i know a little, and i have a copy of the haynes manual! I don't have any way of connecting the ECU up to a computer to get error read outs etc...

thanks for your help,

WiLL......... :)

November 8, 2007

It sounds to me like a bad water temperature sensor. I put a adjustable resistor on mine to manually control richness and a switched diode on my O2 sensor to control lean-ness :P Together I get manual tune of my system but I would strongly recommend a Air Fuel gauge if you attempted it.

When the engine is cold it puts idle around 1300 and dumps around 3.9% more fuel in. Could be why your getting low KPG.

But yeh, sounds like a bad water temp sensor or wiring to.

Taken from my notebook on the water sensor mod

" Starting at the baseline (idle=700 RPM, temp=185) note the "Short-term fuel trim percentage" which is -1.6%. As the control is adjusted to add more resistance, you can see a couple of things happening:

○ The coolant temperature decreases

○ The idle speed comes up

○ The short-term fuel trim increases

The latter point is what you're interested in. As this percentage goes up, that means that more fuel is being shot into the engine. More fuel can give you more power.

The greatest increase I saw was around "idle = 1050". The short term percentage bounces around a bit, so it can be hard to get a solid upper-bounds. The 3.9% number was pretty consistant at this point - that's a real increase in fuel flow when compared to the root -1.6%!(fuel flow) "

November 11, 2007

Thanks for the help!

i will check out the sensor and see what i can come up with! Haven't had time to look at it yet as i have been spending most of my time fixing a mates 1973 VW beetle :-)

WiLL........

It sounds to me like a bad water temperature sensor. I put a adjustable resistor on mine to manually control richness and a switched diode on my O2 sensor to control lean-ness :P Together I get manual tune of my system but I would strongly recommend a Air Fuel gauge if you attempted it.
When the engine is cold it puts idle around 1300 and dumps around 3.9% more fuel in. Could be why your getting low KPG.
But yeh, sounds like a bad water temp sensor or wiring to.
Taken from my notebook on the water sensor mod
" Starting at the baseline (idle=700 RPM, temp=185) note the "Short-term fuel trim percentage" which is -1.6%. As the control is adjusted to add more resistance, you can see a couple of things happening:
○ The coolant temperature decreases
○ The idle speed comes up
○ The short-term fuel trim increases
The latter point is what you're interested in. As this percentage goes up, that means that more fuel is being shot into the engine. More fuel can give you more power.
The greatest increase I saw was around "idle = 1050". The short term percentage bounces around a bit, so it can be hard to get a solid upper-bounds. The 3.9% number was pretty consistant at this point - that's a real increase in fuel flow when compared to the root -1.6%!(fuel flow) "

April 30, 2008

I have a 1993 Corolla 1.3 GLI AUTO.

It has 68k on the clock.

The car is in mint condition.

I usually top-up 10 litre every weekend.

Most of the driving is in the city.

It only gives me around 60 miles.

What do you guys think about the usage?

It drinks a lot?

July 19, 2008

I have a 1993 Corolla 1.3 GLI AUTO.
It has 68k on the clock.
The car is in mint condition.
I usually top-up 10 litre every weekend.
Most of the driving is in the city.
It only gives me around 60 miles.
What do you guys think about the usage?
It drinks a lot?

I have corolla 1.3 1993 Manual its does 238 miles in 38 lit, avera 6.26 mil/lit