Question2006 Scion tC 20K miles (2AZ-FE) engine. Had dealer install TRD Supercharger kit a few months ago.
Car has sporadic problems starting with engine cold (not ALWAYS when the engine is cold...but if it does happen, the engine IS cold). Outside temp does not seem to matter (has happened from 30 degrees to 80). Starter works, but engine wants to die. Coax it with light gas and she goes immediately. Once started have no problems with idle or dying. Each restart is no problem. Idle and acceleration are fine and absolutely no CELs/codes. No smoke from tailpipe. If I gas it, a slight smell of fuel but that goes away.
First dealer drove it for 9 miles and declared no problem (driving 9 miles to troubleshoot a cold hard-start?). Second one installed a new ECM. Problem is back 3 days later.
Spark plugs and gap look good (swapped plugs just in case). EFI relay in fuse block looked good too. Also tried fuel system cleaner too. Dealer said they had a fuel pressure gauge on the car overnight and didn't see anything (if I believe that)...TRD S/C kit adds larger injectors, but does not come with upgraded fuel pump, but most people suggest that I have one. Not sure if that is the culprit. I want to say if I prime the pump by holding the key to ON before starting it dimishes the problem, but as it is sporadic it is hard to conclude anything there. Coolant temp sensor, idle air, fuel pressure reg?? Don't know where to start.
Tired of taking to the local dealer where they grasp as straws. Any ideas?
AnswerYes, just one, try cleaning the inside of the throttle body, a lot of times these engines develop carbon deposits in the inside of the throttle body which will cause hard starting and idling problems/stalling, it can be cleaned by removing the air intake hose and opening the throttle while spraying throttle body cleaner inside and using a stiff brush to remove all of the carbon gunk, it works in most cases.
