So I've read many of the posts online about hot start issues but I can't seem to find any that have the exact symptoms of my car.

​​​​​​When I start my car and it's completely cold (ex. It's sat overnight) it starts up fine. If I go for a drive, turn the car off and then immediately start it back up it's fine. The problem occurs when I turn the car off and let it sit for more than ~15 minutes and then try to start it. It cranks fine and the cranking speed seems to be the same but it has to crank for a good bit before it starts. I would say it has to crank for about 5 seconds before starting.

I know that due to heat every car will usually take a slight bit longer to start when warm, however this seems unusally long and the car hasn't always been like this. It does seem to help if I step on the throttle.

Some mantenece info that might be useful:
New spark plugs - oem
new coils and harness connectors
Billman tct
Replaced the starter with a low milage oem denso unit
The car is MY04 150,xxx miles

Thanks in advanced.

 

You do or don't have new spark plugs, in the car?

 

I do

 

Hmm. At 150K mi, I'm thinking it's injectors. If they're dripping badly they might get "over-primed" by the fuel pump in the several minutes after you shut down. (The pump re-pressurizes the system every few minutes when the car's off; sit in a quiet place and you'll hear it buzz). So extra-drippy fuel + warm-engine spark timing = rough start. When everything's cold, though, the ECM runs super rich anyway so its timing will be okay.

Have the injectors professionally cleaned (don't bother with Seafoam and the like, your injectors are beyond that level of help).

 

Thanks for the response, I forgot to mention about 5k miles ago I had a misfire and it ended up being a bad injector. I know this because I tried almost everything related to misfires and fianly had all my injectors cleaned at a place near me called Fuel Injector Connection. One of the injectors was bad so i ordered an oem replacement from ballade.After I replaced the bad Injector the car ran and started up fine. Do you think the injectors could still be at fault after being serviced?

 

I have had a similar issue since ive owned my car (almost 5 years) when it does turn over is it at a very low rpm that quickly rises to 1k?

 

No in my case the car idles normally once it's started.

 

Lol well there goes my theory.

It's still possible that it's injectors, just a lot less likely. Some people claim that even professional cleaning is a losing battle -- injectors eventually just go bad. But with new OEM parts at $175 each these days, it's a big ask to replace them on a hunch.

My recommendation: as long as the car runs well, just live with the extra few seconds of cranking. Since the engine's already warm, it's well-oiled, so you're really not even causing any extra wear.

 

There's a point where my engine bay gets heat-soaked enough to have hot-start issues. I've mainly had this happen at track days when I didn't pop the hood between sessions but there have been times where I was just beating on the car and had similar results.

In other words, how hot are your hot starts? Is it an issue every time or only on hot days/after a hard drive?

 

It's an issue after every drive