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Oct 2, 2009 | 04:17 PM

corvettebob1

Thread Starter

Melting Slicks

Joined: Dec 2003

Posts: 3,315

Likes: 17

From: Near Jacksonville Fl.

How long

Should your fuel rails retain pressure after your car is shut down?
I'm chasing a hot start problem and I've found the fuel rails lose pressure soon after I shut off the engine.

Oct 2, 2009 | 06:41 PM

95vettski

Safety Car

Joined: Mar 1999

Posts: 3,611

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From: Toronto, Canada

What type of fuel system do have? Stock or aftermarket?

Oct 3, 2009 | 10:50 AM

corvettebob1

Thread Starter

Melting Slicks

Joined: Dec 2003

Posts: 3,315

Likes: 17

From: Near Jacksonville Fl.

Almost stock, just a MSD fuel pump booster.
I timed it yesterday I shut it down it had 60# at the rail within 10 minutes it lost 20# and in 30 minutes it was at 0#

BTW, I'm running 42# SVO green top injectors.

Oct 3, 2009 | 02:09 PM

tail_lights

Race Director

Joined: Apr 2009

Posts: 10,581

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From: SE TEX

Mine drops almost instantly, at least on the gauge. A&A fuel system here.

Oct 3, 2009 | 07:12 PM

95vettski

Safety Car

Joined: Mar 1999

Posts: 3,611

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From: Toronto, Canada

Leaky injector? Do you smell any fuel under the hood or in the garage if parked?

Oct 3, 2009 | 08:00 PM

69dodgecharger

Melting Slicks

Joined: May 2004

Posts: 2,103

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From: Oakley CA

From my experience it is normal to loose pressure in the fuel system over a few minutes after it is shut down.

Oct 4, 2009 | 02:38 PM

corvettebob1

Thread Starter

Melting Slicks

Joined: Dec 2003

Posts: 3,315

Likes: 17

From: Near Jacksonville Fl.

Quote:

Originally Posted by 95vettski

Leaky injector? Do you smell any fuel under the hood or in the garage if parked?

Yes I do get a smell, and this is what I'm leaning toward. Is there any way to check which one?
The stock system has a check valve in the line so I'm sure it should hold pressure fo some time longer then 1/2 hour.
Any good sources to clean and flow injectors and how much $$?

Oct 4, 2009 | 03:24 PM

tail_lights

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Joined: Apr 2009

Posts: 10,581

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From: SE TEX

Quote:

Originally Posted by 95vettski

Leaky injector? Do you smell any fuel under the hood or in the garage if parked?

I don't. Should I be worried?

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Oct 5, 2009 | 02:49 PM

corvettebob1

Thread Starter

Melting Slicks

Joined: Dec 2003

Posts: 3,315

Likes: 17

From: Near Jacksonville Fl.

Quote:

Originally Posted by tail_lights

I don't. Should I be worried?

Probably not since you have the A&A system.

Oct 5, 2009 | 03:06 PM

#10

user_name

Melting Slicks

Joined: Feb 2006

Posts: 2,163

Likes: 5

From: Houston

I checked mine when I added a return line and 97 rails. It definitely drops, but you won't see 0 w/o a leak.

Oct 5, 2009 | 05:13 PM

#11

tail_lights

Race Director

Joined: Apr 2009

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From: SE TEX

Quote:

Originally Posted by corvettebob1

Probably not since you have the A&A system.

Oct 6, 2009 | 11:50 AM

#12

corvettebob1

Thread Starter

Melting Slicks

Joined: Dec 2003

Posts: 3,315

Likes: 17

From: Near Jacksonville Fl.

Quote:

Originally Posted by user_name

I checked mine when I added a return line and 97 rails. It definitely drops, but you won't see 0 w/o a leak.

That's what I thought, what pressure does your drop to?

Oct 6, 2009 | 11:56 AM

#13

user_name

Melting Slicks

Joined: Feb 2006

Posts: 2,163

Likes: 5

From: Houston

Quote:

Originally Posted by corvettebob1

That's what I thought, what pressure does your drop to?

I think I waited about 20 minutes and was at 35psi or so. I know there was plenty of pressure the next day b/c fuel shot all over the place when I pulled the gauge off.

Oct 9, 2009 | 03:08 PM

#14

corvettebob1

Thread Starter

Melting Slicks

Joined: Dec 2003

Posts: 3,315

Likes: 17

From: Near Jacksonville Fl.

Quote:

Originally Posted by user_name

I think I waited about 20 minutes and was at 35psi or so. I know there was plenty of pressure the next day b/c fuel shot all over the place when I pulled the gauge off.

Thanks for the info, last night I added a bottle of Techron fuel system cleaner to ~5 gal of fuel left in the tank. (Supposed to treat up to 16 gal).
This morning I drove to the Chevron station about 9 miles filled it up and added another bottle good for 20 gal of fuel.
Then drove another 20 miles and shut it off for about 1 1/2 hours, gage under hood showed around 35 psi and when I started the engine she fired right off.
Drove another 30 miles and shut it off and after 2 1/2 hours it still had around 35 psi and fired right up.

It looks like my leaky injector has been my hot start issue for some time.

Now it's time to move on to the heads and cam project and bigger injectors.

Will it ever end????????

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