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Discussion Starter · #1 ·
My 2004 Trajet 2.0 petrol is idling high when warmed up... in around 1500rpm… I tried two full second hand throttle body’s with no luck tried a second hand mapping sensor also did not rectify it. All vale pipes seem fine. Any help would be greatly appreciated.
Martin
 

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Discussion Starter · #3 ·
No, car starts up okay, idles fast then sits at a constant 1500rpm when heated up full. doesnt get any higher or lower constant 1500. since last post have tried another Mapping Sensor, Vap sensor and Engine Coolant Tempeture switch ECT. still idleing at 1500
 

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Discussion Starter · #5 ·
yes have changed the Air flow sensor which on 2.0l petrol is the Map Sensor. also done the intake air tempeture sensor (IAT) also the Trottle postiton sensor (TPS) Engine Coolant Tempeture switch (ECT), also the idle speed control actuator (ISC) also the Vap and checked the Air filter housing and all air valve pipes checked too. Car still idles at 1500rpm when warmed up, when cold it is about 900rpm
 

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Hi
What left is the ECU , can it be faulty . For a good electronics engineer it is possible to monitor the control signal coming from the ECU to the ISC which is the main cause for such an error . or maybe provide an external control signal to the ISC to make sure it opens and closes as required . For exact pins and voltages to do the test see Hyundai America ,lots of data and tests there , ask for assistance of electronics technician . The ISC controls the air flow in the bypass to the throttle and this controls the engine rev.
when idling .

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Discussion Starter · #7 ·
Yes that is the next avenue to be explored the ECU, and take readings from the switches to the sensors. I have one last thing to try also, to check the timing. It is controled by the Specialised Computer which i am having difficultly sourcing outside of a Main Dealers. I will post agian later in the week when i have an update.
Thanks All
 

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Discussion Starter · #8 ·
We checked the Timing and it was fine, also checked both the crankshaft and the camshaft sensors which also were fine. We did however find the root of the problem, there was a wire broken in the loom going to the ISC actuator; it was in the 90 degree bend just below the switch. When we repaired this wire the engine was able to regulate the idle speed back to normal. This fault has taken weeks to find, and is so simple now when you see it. Thanks you to those who commented.
Regards
Martin
 
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