Hello, my name is Sergio, i'm from Spain, new to this forum. I'm here trying to find someone who know something about the problem in my car. I've done a full engine rebuild, with the internals stock except for the oversized pistons. After the rebuild, i fitted the engine in the car with a full 3" decat line, and the car doesn't keep in a regular idle, it varies continuously. I've checked all the vacum lines (they're fine) and changed the throttle body an did the basic settings, checked the timing, changed fuel pump, checked the injectors and the engine loom. The car works well while driving, but the idle is all the time varying. I'm starting to thing that the values on the ecu can't keep the idle because of the oversized pistons and the 3 inch exhaust line as the engine could loss certain backpressure. Has anyone experienced something similar after a rebuild? Sorry about the mistakes in the writing, i'm sure that there are a lot...
I have used 3inch exhaust on stock engine than oversised to 83mm , no idle issues. not even with 1000cc injectors (ID1050-XDS injector dynamics) , nor on factory EMS3125 ECU , nor on my actual setup Motec M130 , so the problem is not this. you may check for short trim lambda values if you have EMS3110 or check for AFR in generic OBD if you have EMS3125 that runs , to check for minimal air leaks. also check for VTC values at idle / low load. check all the vacuum tubes , cansiter , etc etc. another thing , the timing is possible to be altered due to some multiple cambelt replacements. you can check that with the timing light but yet again the factory ECU will not allow for crank index position compensations but worth to check for the piece of mind.
