Pressure in fuel rail after engine shutoff..

[Barnes]

How long should there be fuel pressure in the rail after you turn the car off?

I was working on my car last night, and noticed that after about 2hrs the pressure was down to 0psi. I don't think that's normal.

 

[SleepinGVR4]

I believe its different for every type of fuel pressure regulator. Some bleed off fast and some hold pressure for a while. What FPR do you have?

Someone correct me if i'm wrong.

 

[strokin4dr]

I have an aeromotive fpr and mine does the same thing. Others have had this happen with aftermarket fpr too. It takes a couple of seconds for the car to crank in the morning, but other than that I have no issue with it.

 

[Barnes]

K. I can't believe I forget the name. The one that bolts straight to the rail. They only did a limited run.

Anyways, I guess that still leaves me pondering.

I'm still convinced I've got a bad injector. I guess I'll find out soon enough when I get my Keydiver ECU and I can put my 660's in.

 

[icurunnin]

another reason could be the fuel pump bleeding down. had that happen on 501 and had to tighten the clamp on my pump.

 

[GVR4_1057]

It is pretty normal for the AFPRs to bleed off pressure right away. It used to bother me then I realized that there may be an advantage that it gets another couple engine rotations in to get the oil pressure higher before it fires. Maybe it doesn't matter that much /ubbthreads/images/graemlins/dunno.gif

 

[Rausch]

My Aeromotive held for like a week, and after that woudl bleed down in a matter of minutes. FWIW. Other than the mentioned extra cranks, no harm, no foul.

 

[Barnes]

Well. I was just curious mostly because I'm trying to diagnose my injectors. I think one leaks. Weird idle issues, and the occasional backfire make me suspicious.

 

Jon,remind me when I do your chip and I'll add some extra code that runs the fuelpump for the first 5 seconds when you turn the key on. That primes the pump and lines for you, so starting will be easier.
As far as the injectors, if you suspect a leaky injector I would send all 4 of them to Rich at CruzinPerformance and have them cleaned.

 

[Barnes]

Thanks Jeff. Although it seems to start fine for me. So maybe I don't need it. :shrugh:

The injectors I have now are bone stock. I think when I put the black car down for maintainence I'm going to send off all 8 450cc injectors and get back on nice clean set. /ubbthreads/images/graemlins/smile.gif