Idles at 1000rpm, whats wrong ?

[Thraxeh]

Heres the deal. My camry idles at 1000-1200rpm at normal operating temperatures.

When i do the diagnostic code thing, i get a code 43 which is...

Code 43 is "Starter Signal"
No STA signal to ECU when vehicle stopped and engine running at over 800RPM.

When i do the diagnostic code while the engine is running, the revs drop down to 700rpm, and stays at 700rpm, untill i take it out of diagnostic mode, then it returns to 1000rpm...

Any ideas ?

[toyomoho]

Code 43 might be the starter relay or wiring to the ECM. When the engine is cranked, a voltage is sent from the relay to the ECM to increase the fuel mixture. If no signal, the voltage may not be getting to the ECM.

[Thraxeh]

Originally Posted by toyomoho

Code 43 might be the starter relay or wiring to the ECM. When the engine is cranked, a voltage is sent from the relay to the ECM to increase the fuel mixture. If no signal, the voltage may not be getting to the ECM.

so inturn the car thinks its cranking, and giving it more fuel when it shouldnt be ? or maybe not, i dont see what the cranked fuel mixture has to do with the idle speed :S

Why does the car drop to 700rpm's when i put the ECU(ECM) into diagnostic mode ?

[Doctor J]

I assume that the car is 87-89 four cylinder.
The diagnostic check must be done with ignition on, engine not running.
At temps below 68 degrees F, the car runs at higher rpm until it reaches normal operation temperature (the fans kick-in at least twice).
Code 43 is set if the car started with remote starter switch.
If the engine is hard to start in a cold weather, then the STA circuit from neutral start switch or starter relay needs to be checked.
When test terminal is grounded with engine running, the idle speed drops to base setting(700rpm) so this drop is normal.
The causes of higher then normal rpm are;

• electrical load such as headlights on or defogger on
• no neutral signal to the computer(a/t only)
• fans running constantly
• idle up a/c screw is open all the way
• plugged pcv orifice.

[Thraxeh]

Originally Posted by Doctor J

I assume that the car is 87-89 four cylinder.
The diagnostic check must be done with ignition on, engine not running.
At temps below 68 degrees F, the car runs at higher rpm until it reaches normal operation temperature (the fans kick-in at least twice).
Code 43 is set if the car started with remote starter switch.
If the engine is hard to start in a cold weather, then the STA circuit from neutral start switch or starter relay needs to be checked.
When test terminal is grounded with engine running, the idle speed drops to base setting(700rpm) so this drop is normal.
The causes of higher then normal rpm are;

• electrical load such as headlights on or defogger on
• no neutral signal to the computer(a/t only)
• fans running constantly
• idle up a/c screw is open all the way
• plugged pcv orifice.

Its a 1990 SV21, but has the same codes i believe

There are no loads on the engine, and the fans are not running, when i get the 1000rpm, I will check the idle up screw for the AC. Where can i find the PCV orifice ?

Not to sure on the "no neutral signal to the computer(a/t only)" i will have to have a look.

[Doctor J]

The idle PCV orifice is the small passage that goes around the throttle plate and used to suck the crankcase gases at idle speed into the engine intake.
When the car with a/t is in neutral or park, the computer receives signal from neutral start switch to reduce the rpm. When the car is put into gear, the rpm goes up slightly to prevent stalling under initial load.

[Thraxeh]

all signals to ECU are fine.

AC idle up is fine, and also the screw that fine tunes the idle on the throttle body is also tightened as far as it will go(less rpm), but its still at 1000rpm.

its looking like i have to give the Throttle body and ISC a clean, if the problem is still there, then i have no idea...