Hard start when hot

[ninetyfive]

If I get to temperature and park the car, after 15 minutes it starts right up, but after 30-40 minutes it takes it a good seven seconds of cranking. Starts up right away when cold. Fuel regulator was replaced last year.

Any ideas?

 

[Steve-Indy]

Recurrent leakdown ?

 

[Viper Specialty]

If I get to temperature and park the car, after 15 minutes it starts right up, but after 30-40 minutes it takes it a good seven seconds of cranking. Starts up right away when cold. Fuel regulator was replaced last year.

Any ideas?

Check fuel pressure drop-off and boil-out with a gauge. If it tests OK, what you describe is also a symptom of an impending PCM failure. They start to become erratic when the module gets warm.

If signs point to that, DO NOT TAKE LIGHTLY. G1 modules fail catastrophically in most cases, and the cost different between a partial reman and a total reman + invalid core is thousands different.

 

[DickDavis]

Who does the remans?

 

[Goggles Pizano]

Who does the remans?

He does.

 

[MoparMap]

Check fuel pressure drop-off and boil-out with a gauge. If it tests OK, what you describe is also a symptom of an impending PCM failure. They start to become erratic when the module gets warm.

If signs point to that, DO NOT TAKE LIGHTLY. G1 modules fail catastrophically in most cases, and the cost different between a partial reman and a total reman + invalid core is thousands different.

Is this the same for later gens? My gen 3 has some pretty inconsistent starting characteristics, but I haven't had a chance to get a gauge to hook to the fuel rail yet. Not always a hot start issue either, every once in a while it does it on the first start of the morning, but not nearly as noticeable as after some heat soak. It's not necessarily that it doesn't "start" either, more just like it starts really weakly. By that I mean you hear it catch and fire so you let go of the button and sometimes it just barely keeps itself going at what could only be a few hundred rpm at most before coming up to idle. It's almost like a hit and miss engine where you think it's dead and it just rolls over enough to hit the next cylinder. Giving it some throttle during cranking when it doesn't fire right away seems to pretty reliably start it well though, so thinking it's something else.

 

[Viper Specialty]

Is this the same for later gens? My gen 3 has some pretty inconsistent starting characteristics, but I haven't had a chance to get a gauge to hook to the fuel rail yet. Not always a hot start issue either, every once in a while it does it on the first start of the morning, but not nearly as noticeable as after some heat soak. It's not necessarily that it doesn't "start" either, more just like it starts really weakly. By that I mean you hear it catch and fire so you let go of the button and sometimes it just barely keeps itself going at what could only be a few hundred rpm at most before coming up to idle. It's almost like a hit and miss engine where you think it's dead and it just rolls over enough to hit the next cylinder. Giving it some throttle during cranking when it doesn't fire right away seems to pretty reliably start it well though, so thinking it's something else.

While I have seen it on Gen-2+, its not nearly as prevalent or obvious as with Gen-1 cars. What you describe is far more likely a fuel pressure regulator in the module bleeding off too rapidly and allowing boil-out, and taking time to refill the rails completely.