Hello guys! I am having some trouble figuring out some idle issues with my car. I have a 2002 Lancer OZ Rally with an engine swap. I did the swap 3 years ago. The engine is the 4g64. I just replaced the MAFS and TPS. I also replaced the old beat up air box with a cold air intake. Since day one the car has idled higher than I think it should. Everything I have read says this car should idle between 750 and 850 rpms, however mine is idling at 950-1200 rpm. Also it will occasionally sputter on acceleration. I have an OBD2 reader and it shows my throttle to be at 60% even when the car is off with the ignition in the on position.

I know it is a no-no to adjust the throttle screw, but could that have been messed with by the previous owner of this engine to compensate for something and cause the TPS to be getting more voltage than is normal?

Any ideas or direction on what could be done to correct this problem?

 

I tested the new tps and it shows bad A new one is on the way. Should have it Monday. I also cleaned the iac module and that seemed to smooth out the idle however it is idling a lot higher now.

 

well let us know how it goes? and nice job on the swap btw

 

So the part should be here today since yesterday was MLK day. However I have been doing some more research and am finding a lot of people with the same problem in the DSM forums and most of them are saying it is either fuel filter\pump related or plugs\wires. I was leaning towards fuel filter but I'm not sure where it is located or if the 02 lancer even has one since I haven't been able to find any auto parts store selling them.

 

The only filter an 02 lancer has is the sock at the end of the pump. but if you readings are right a fuel pump will not cause your "app" to stay at 60% but can cause running issues if your fuel pressure is falling below spec.

 

Well I was thinking that the hesitation part of my acceleration could have something to do with low fuel pressure. But while driving it just now it didn't seem to hesitate as much. Could the hesitation have been from the computer adjusting to the new MAFS?

 

Does your lancer sound like a subaru when you accelerate? Any codes? Also the TPS needs to be adjusted which could of been your issue.

 

Yes there is one code. It says the TPS is bad. And the car does sound a little like a subby at high rpm, 3k or higher. How do I adjust the TPS?

 

I'm starting to wonder if the problem is my IAC valve.

 

I have attached 2 screen shots from torque odb2 that show some problems. I will post another screen shot of the errors in a bit.







Any one have an idea what these mean?

 

What ecu and tps you using? i know on a lancer, the way to adjust the tps is to check the voltage. if you're looking at the tps with the round part of it facing you, the connection on the right is 1 (sensor output) middle is 2 (ground) and 3 is on the left. you would connect 1 and 2 to a multimeter with ignition to on without starting. voltage needs to be in a range between 335-935mv, if it isn't, loosen the screws and adjust till it falls in. But I'm not sure what range the 4g64 needs to be set at.

 

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Where can I get the special tool they describe in the instructions and do I need it to properly adjust the TPS?

Something curious. I just discovered while reviewing my data log is that my coolant temp is seen as 201 degrees f at start. And during drive it only gets to 206. Could this be keeping the car from entering closed loop? Strange thing here is that it isn't having code P0128 but it also isn't running in closed loop.

 

Here are the errors I am getting. Also both the TPS and the MAFS are brand new.



Also this weekend I plan to test my o2 sensors and see if they might also be a problem, even though I'm not getting a code for them. And I will be removing and cleaning my throttle body. I want to make sure I give it a thorough cleaning.

 

The way to adjust the TPS on the 64 is by loosening the screws holding it on and move it to one side or the other but you'll also need a scan tool or you can use the torque app to adjust it to the right percentage. Should be between 13 & 14% with the throttle closed. I'm having the same sputtering issue but for me it's because of a cylinder 2 misfire. I would say check you IAC though. I've had that P0101 code before due to poor IAC wiring because of a diamante TB swap.