Hi everyone,

My G37 '08 6MT has problem when starting the car, it starts but it takes longer when the engine is warm, there are no issues when the engine is cold.

So far, I identified some parts that could cause the problem
1- starter
2- fuel pump relay
3- coolant temperature sensor

I will bring the car to the garage soon, I just want to know if someone had similar issues.

Thank you

 

How many miles on your car? Have your spark plugs been replaced? I seem to recall a similar issue and it boiled down to spark plugs.

If you're beyond 80k miles you might want to look into replacing soon.

 

Happens to me. Hard starts when it's warm... I'm on 45k... Battery barely a year old.

 

I had a problem like that once - turned out to be split diaphragm in the fuel pressure regulator. Pulled the vacuum hose off when the engine was running and gas came out. When shutting down the hot engine, residual pressure in the line would force the fuel to run into the intake and flood the engine. After it'd been shut down for an hour or so the flooding would dissipate and the engine would start normally.

 

What is a "hard start" ? Gotta know what to look out for I guess. My car is still pretty low on mileage but I like future reference stuff

 

I'm gonna go replace my battery this weekend..... had to jump start twice this week... from a cold start.. hard start is still there when warm.. alternator is good... fuel pump is good... only other thing im thinking on is the spark plugs but im changing those when i change my UIM. gonna do a ecu reset tonight also...

 

Its not likely to be the starter, fuel pump, or spark plugs given the cars mileage. Have you checked the throttle body's? At 80k if they are full of carbon you will certainly have hard starting and idle issues. The VQ37VHR is known to build carbon in the throttle body's and air intake plenum. Its an easy thing to check and fix and there are several DIY's on this site.

 

My throttle bodies do need cleaning but was saving that until I did uim also. .. for the OP that would be a good thing to check

 

what is the UIM?

 

Upper Intake Manifold

 

I still ask...what is a "hard start" ?

 

It's the opposite of an 'easy start'.

 

Idk OP's definition for it but for me a hard start is like when it sounde like the crank is struggling to turn. Then it even does... I got my battery on a slow charge back to "normal" ... If it still acts up then a Duralast battery or Optima battery is going in... I should buy the Z1 intake now and do a full service right now...