Over Fuelling and rough idle when cold

[Yellow GT]

Hi im new to the group. I've got a 94 GT and its developed a problem where its is running very rough when its cold but this stops when the car warms up a bit. Since this problem has started the car has also started over fuelling running rich and burning a ridiculous amount of fuel. I've changed the MAP sensor, cleaned the ICV and cleaned the Lambda sensor but has made no difference. The car has a Greedy Emanage Ultimate fitted but has been set to its default settings. Any help would be great. Thanks

 

[Jay]

Welcome to the site.

You getting any fault codes?

I had similar with one of mine and it turned out to be the coolant temp sender. ECU was overfuelling to the point where I got fuel in the oil. Seen it in other cars too.

Theres a few other bits its could be but that's where I'd start just going on experience.

 

[Yellow GT]

Thanks for the reply mate. To be honest i haven't ran any diagnostics as ive only found the diagnostic port in the engine bay yesterday. I've heard of the problem with the coolant temperature sensor before. Do you know where I could get buy a new sensor as id rather be able to get a new sensor rather than a used one. What could the other causes be also ? Thanks

 

[Jay]

Could also be a vacuum leak, duff lambda probe, injector issue, would definitely start with the fault codes in case something is logged.

https://www.toyotagtturbo.com/community/index.php?threads/efi-self-diagnosis-system.71074/

 

[Jay]

Oh and I've had mixed results with aftermarket sensors so if you give your chassis number to a Toyota parts man and tell them what you want he should be able to price one up. It's the green one under the distributor. If the distributor oil seal starts leaking it can saturate the sensor and wiring in oil causing all sorts of mayhem.

 

[Yellow GT]

Oh and I've had mixed results with aftermarket sensors so if you give your chassis number to a Toyota parts man and tell them what you want he should be able to price one up. It's the green one under the distributor. If the distributor oil seal starts leaking it can saturate the sensor and wiring in oil causing all sorts of mayhem.

Hi sorry haven't been on here for a while. I've just ran the diagnostics yesterday using the link you posted and its showing fault code 14 which is ignition etc. Is there any common problems to look out for with this code as i dont want to start changing the distributor or leads etc if i dont need to

 

[SKINY]

Ah code 14 aka the cnut code
Check the condition of the roter arm and dizzy cap, leads too, end to end should read around 25 ohms with a multimeter
Broke my heart with this code on a celica, was able to get the workshop manual and check all the ohm values of the components before I started throwing parts at it.
Not sure if the starlet workshop manual has that section, Jay would know better

 

[Yellow GT]

Ah code 14 aka the cnut code
Check the condition of the roter arm and dizzy cap, leads too, end to end should read around 25 ohms with a multimeter
Broke my heart with this code on a celica, was able to get the workshop manual and check all the ohm values of the components before I started throwing parts at it.
Not sure if the starlet workshop manual has that section, Jay would know better

Cheers mate it looks like is going to be a process of elimination from here. I'll check them bits you mentioned later and see if i can find the culprit (hopefully)

 

[Yellow GT]

Checked the leads and they're reading 10, 9, 7, 5 from longest to shortest would i be right to say these values are too low ?