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Old 08-16-2008   #1
ZWILD1
 
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Default Fuel system questions help needed

I replaced fuel injectores and pcv hose that houses the pcv valves. No more miss car idles smooth. But I think it still feels like I lost power on top end and plugs are still too clean. They are white but I have no codes showing to indicate a lean condition. Fuel pressure test ignition on reads 42 psi. , at idle seems to have dropped to 41 psi from 43 psi before injector change. Not sure how to determine if I have a fuel pump ,regulator or ,pulsator problem. With ignition on the pressure does seem to bleed of very slightly. Any thoughts would be appreciated. Car does have 104,000 miles now. So keep that in mind.
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Old 08-16-2008   #2
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Default Re: Fuel system questions help needed

If your plugs are white then your running too lean. They should be tan to brown in color. That could be your power issue. Sounds like it's time for a tune.

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Old 08-16-2008   #3
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Default Re: Fuel system questions help needed

You are saying ignition on but the engine off? It should be closer to 50psi when there is no vacuum on the regulator.

With the car running and the gauge on, look at the pressure at idle, and the pressure when you pull the vacuum fitting off the regulator.
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Old 08-16-2008   #4
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Default Re: Fuel system questions help needed

Quote:
Originally Posted by Aurora40
You are saying ignition on but the engine off? It should be closer to 50psi when there is no vacuum on the regulator.

With the car running and the gauge on, look at the pressure at idle, and the pressure when you pull the vacuum fitting off the regulator.
When I pulled the vacuum off engine running it was like 46 psi.
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Old 08-16-2008   #5
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Default Re: Fuel system questions help needed

Hey Bob,
Was that photo taken at Capitol Raceway? I've been there a few times like at all Corvettes day.
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Old 08-17-2008   #6
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Default Re: Fuel system questions help needed

Quote:
Originally Posted by ZWILD1
When I pulled the vacuum off engine running it was like 46 psi.
But it's 25psi when turning the key on? That also would have no vacuum.

What is it when idling with the vacuum hose in place?

Quote:
Originally Posted by ZWILD1
Hey Bob,
Was that photo taken at Capitol Raceway? I've been there a few times like at all Corvettes day.
My signature picture rotates, but yeah I believe one of the pictures is from the parking lot at Capitol.
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Old 08-17-2008   #7
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Default Re: Fuel system questions help needed

Are there any little black or gray speckles on the porcelain of the plugs?
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Old 08-17-2008   #8
ZWILD1
 
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Default Re: Fuel system questions help needed

It was like 42psi at idle. I pulled the fuses and checked each pump key on and they both showed 46 psi cold. Next I let engine warm up and I was getting 42 psi at idle. I position gauge so I could see what it would read as I gave more throttle. It would start to climb with rpm's but would drop back even if I held at like 4k. So I blocked of the vacuum to the regulator and got a steady 52 psi. I drove it blocked off and it pulls like gang busters. No codes either way blocked or with vacuum just feels lame with the regulator getting vac. I do remember my tail pipes used to get black between car washes. Now there is no soot. Plugs still seem white but no speckles. I wonder pumps or regulator, or pulsator.All I Know is at 52 psi constant it runs strong like it used too.
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Old 08-17-2008   #9
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Default Re: Fuel system questions help needed

Sorry if I confused you but I didn't read gauge right. It was always 42psi running at idle,and 52 psi vacuum off regulator.
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