CH Lancer Rough start

crumpledoor13

New Member
Hi all. My 04 CH is struggling to start when cold. It will crank over and splutter to a start, then get to normal idle and be fine. Car runs fine and when warm starts without issue. Its getting worse to the point it almost wont start when cold. Seems like it isn't getting enough fuel to fire up straight away when it's cold. Could this be a faulty relay for the fuel pump prime? Where are the fuel pump relays located if that could be the issue? Thanks
 

SDate42

Active Member
Lifetime Premium Member
Hey there!
Fuel pump relay lives in the drivers side fusebox. Pull down the “hidden” glovebox and remove it from the trim. You’ll find the relay there. Being as yours is 2004 - im gonna say 4g94. The fuel pump does not prime. It runs only when the engine is turning. This is to build oil pressure BEFORE the motor has fuel and can be started.
If you wish to test the fuel pump, bridge the relay with a paperclip or short run of wire. Have the fuel line removed from the rail and make a friend watch the fuel coming out. Being as your motor runs fine when warm, I wouldnt bother checking.

personally I would check the idle air controller function - reset its zero position. Test for airleaks with a smoke machine. Maybe a dirty throttle body or dud position sensor. Ideally you need a smoke machine and a scan tool to pull live live data.
 

crumpledoor13

New Member
Hey there!
Fuel pump relay lives in the drivers side fusebox. Pull down the “hidden” glovebox and remove it from the trim. You’ll find the relay there. Being as yours is 2004 - im gonna say 4g94. The fuel pump does not prime. It runs only when the engine is turning. This is to build oil pressure BEFORE the motor has fuel and can be started.
If you wish to test the fuel pump, bridge the relay with a paperclip or short run of wire. Have the fuel line removed from the rail and make a friend watch the fuel coming out. Being as your motor runs fine when warm, I wouldnt bother checking.

personally I would check the idle air controller function - reset its zero position. Test for airleaks with a smoke machine. Maybe a dirty throttle body or dud position sensor. Ideally you need a smoke machine and a scan tool to pull live live data.
Thanks SDate42. Yes its the 2.0 4g94. On the weekend I did take out the Idle Air Valve and cleaned it to see if that helped. What I didn't do was disconnect the battery to reset the ECU after cleaning it. I assume this is how you reset it to zero position?
 
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