Toyota Starlet's ECU.

Rookie145

Toyota main dealers told me I needed a new ECU for my '98 Starlet, but I'm not convinced.

Engine management light does'nt stay on once the engine is started,

The problem is the automatic choke, it appears to be staying on. My mechanic thinks it's a temprature sensor. Any ideas out there?

Avns1s

AFAIK they're fuel injected so shouldn't be a choke.

What's the symptoms?

Is it high on emissions, stalling or something else? In other words, if the engine management light isn't advising there's a problem, is there another reason to believe there is one?

Rookie145

Avns1s wrote: »

AFAIK they're fuel injected so shouldn't be a choke.

What's the symptoms?

Is it high on emissions, stalling or something else? In other words, if the engine management light isn't advising there's a problem, is there another reason to believe there is one?

Hi Avnsis.

OK, no choke, but here's why I think there is a problem.

When starting from cold, the engine revs lower then it used to, and as it warms up, it's idling faster then it used to, in other words the situation is oppisate to what it should be, other then that the car is perfectly drivable.

DublinDilbert

Rookie145 wrote: »

Toyota main dealers told me I needed a new ECU for my '98 Starlet, but I'm not convinced.

Engine management light does'nt stay on once the engine is started,

The problem is the automatic choke, it appears to be staying on. My mechanic thinks it's a temprature sensor. Any ideas out there?

I wouldn't be inclined to suspect the ECU, as you hear of very few toyota ECU's giving trouble.

Your mechanic might not be far off with it being a simple sensor, the question is which one!

How long did toyota spend looking at the car?

The question is did they just scan the ECU for error (eg open circuit on a temp sensor ) or did they go in and look at the value being read from the sensor. Nearly every car will only set a DCT if the value is completely out of range (eg <-40C or >120C ). So if your sensor was reading -5C when it actually was 25C, it would not set a DCT.

Rookie145

DublinDilbert wrote: »

I wouldn't be inclined to suspect the ECU, as you hear of very few toyota ECU's giving trouble.

Your mechanic might not be far off with it being a simple sensor, the question is which one!

How long did toyota spend looking at the car?

The question is did they just scan the ECU for error (eg open circuit on a temp sensor ) or did they go in and look at the value being read from the sensor. Nearly every car will only set a DCT if the value is completely out of range (eg <-40C or >120C ). So if your sensor was reading -5C when it actually was 25C, it would not set a DCT.

Hi DublinDilbert.

I don,t know how long they actually spent with the car but I was charged €36 odd for their time. It would appear they just scanned the ECU although I may be wrong about that, what I do know is the price of a new one €1630.00. The car is barely worth that. Which sensor is right, three of them was pointed out to me.

DublinDilbert

Rookie145 wrote: »

Hi DublinDilbert.

I don,t know how long they actually spent with the car but I was charged €36 odd for their time. It would appear they just scanned the ECU although I may be wrong about that, what I do know is the price of a new one €1630.00. The car is barely worth that. Which sensor is right, three of them was pointed out to me.

For €36 they didn't do much work on the car at all, i would suspect. For starters €8 of that is VAT. I would not fork out for a new ECU based on a 5 min scan of the car.

Even without a scan tool you could measure the resistance of the sensor with a cheap meter and find out if its in spec when the car is cold.

Also if you know the correct value of the sensor at say 20C, you could just get a resistor of that value and connect it, and see if the car starts and runs ok.

Rookie145

DublinDilbert wrote: »

For €36 they didn't do much work on the car at all, i would suspect. For starters €8 of that is VAT. I would not fork out for a new ECU based on a 5 min scan of the car.

Even without a scan tool you could measure the resistance of the sensor with a cheap meter and find out if its in spec when the car is cold.

Also if you know the correct value of the sensor at say 20C, you could just get a resistor of that value and connect it, and see if the car starts and runs ok.

Hi Again DublinDilbert. Tried out differant sensors on the car but to no avail. I think Toyota may be right in their assesment, so I've suruced an ECU for it. I'll keep you informed.

kermitpwee

Rookie145 wrote: »

Hi Again DublinDilbert. Tried out differant sensors on the car but to no avail. I think Toyota may be right in their assesment, so I've suruced an ECU for it. I'll keep you informed.

Your throttle body is gone. I had the same symptoms on 2 carina e's and replaced the units with secondhand ones and it solved it.

Thats my 2cents.

Crosshair

Agree about throttle body, it contains IACV which controls air flow into engine at idle, when this sticks it gives your symptoms, seen this lots of times on corollas & carinas