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Discussion Starter · #1 ·
Hi looking for a lil advice and guidance .
I have a 2000 chevy astro van that the other day just started a rough idle and died out on me , cel light came on and gave me a p0300 multiple misfire code. I had it towed home where I checked my plugs, wires, dist cap and play I'm my dist , all look good except for a lil corrosion on the points , so I cleaned them up and moved on to check the fuel system. I plugged up my pressure gauge and found that I had 10 psi key on engine off to prime pump and running I had 50 psi and no leak down so I ruled out the injectors and fuel pressure reg. so I thought I found the culprit with the fuel filter or fuel pump. First replaced the filter and still rough idle and 50psi on line. So I moved to fuel pump , siphoned gas , dropped tank, cleaned up area , removed and replaced fuel pump , spliced new wires , installed tank , put all back together and added some new gas. and first start up was nice idle no miss and cel disappeared. But shortly after warming up is started a light rough idle so I checked fuel line pressure and this time it was 9psi key on engine off and 52psi running. So now my question is did I miss some thing or might I have gotten a bumb new fuel pump ? Andy advice and guidance will be greatly appreciated . I'm just stumped and frustrated.

Thanks in advance
-Anthony
 

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My '01 and '03 both read around 58 to 60 key on engine off with about 56 to 58 running. The van needs almost 60 lbs just to start if I'm not mistaken. I don't know how yours even starts with psi so low...
 

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Common Sense + Critical Thinking
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munstervan13 said:
I plugged up my pressure gauge and found that I had 10 psi key on engine off to prime pump and running I had 50 psi and no leak down so I ruled out the injectors and fuel pressure reg. so I thought I found the culprit with the fuel filter or fuel pump. First replaced the filter and still rough idle and 50psi on line. So I moved to fuel pump , siphoned gas , dropped tank, cleaned up area , removed and replaced fuel pump , spliced new wires , installed tank , put all back together and added some new gas. and first start up was nice idle no miss and cel disappeared. But shortly after warming up is started a light rough idle so I checked fuel line pressure and this time it was 9psi key on engine off and 52psi running.
Well, anything less than 55psi KOEO is unsatisfactory. The poppet valves are picky about pressures due to their design. I am guessing that with your 10psi KOEO there is definitely something wrong, sounds like it's not priming. Cycle the key a few times to make sure that you are getting a good prime for the KOEO test. https://sites.google.com/site/astrosafa ... uel-system

Something to keep in mind that sometimes takes a minute to grasp is that the pump creates flow, and the restrictions create the pressure.

I am guessing a faulty regulator as you have replaced the pump/sock/inline-filter. I would connect your fuel pressure gauge and a battery charger, then jump the fuel pump relay. Slowly pinch off the return line and see if the pressure increases(but don't let it get above 75).
 

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Discussion Starter · #7 ·
ok so I cycled the key on and off a few times and tested the pressure again and now key on engine off pressure has raised to 55psi but running pressure drops a bit to 52psi and when I turn off engine it raises to 60psi and holds.

and I went ahead and rented another pressure gauge tester to be on the same side and its saying the same.
This is frustrating !
Anyone have any clues or advice ?
 

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munstervan13 said:
Dang I don't have a battery charger. is there another way to go about it ?
Well you don't absolutely have to use a battery charger, but it's good practice. Just be quick about it and make sure to charge the battery after.
 

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2000 Lifted 4x4 Astro 92 V8-350 Shorty
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I have 15 psi (TBI) coming out of my pump (on my 92) regulated down to 6 psi, and my carbureted V8 loves it!

Sorry... no help! But I couldn't resist! :D
 

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Discussion Starter · #12 ·
AstroWill said:
munstervan13 said:
I plugged up my pressure gauge and found that I had 10 psi key on engine off to prime pump and running I had 50 psi and no leak down so I ruled out the injectors and fuel pressure reg. so I thought I found the culprit with the fuel filter or fuel pump. First replaced the filter and still rough idle and 50psi on line. So I moved to fuel pump , siphoned gas , dropped tank, cleaned up area , removed and replaced fuel pump , spliced new wires , installed tank , put all back together and added some new gas. and first start up was nice idle no miss and cel disappeared. But shortly after warming up is started a light rough idle so I checked fuel line pressure and this time it was 9psi key on engine off and 52psi running.
Well, anything less than 55psi KOEO is unsatisfactory. The poppet valves are picky about pressures due to their design. I am guessing that with your 10psi KOEO there is definitely something wrong, sounds like it's not priming. Cycle the key a few times to make sure that you are getting a good prime for the KOEO test. https://sites.google.com/site/astrosafa ... uel-system

Something to keep in mind that sometimes takes a minute to grasp is that the pump creates flow, and the restrictions create the pressure.

I am guessing a faulty regulator as you have replaced the pump/sock/inline-filter. I would connect your fuel pressure gauge and a battery charger, then jump the fuel pump relay. Slowly pinch off the return line and see if the pressure increases(but don't let it get above 75).
If the pressure reg was bad wouldn't it leak down immediately on the test gauge ?

I swapped out the fuel pump again just to rule out faulty pump, and still 55psi to prime and 52psi running. Still has a rough start and off idle. swapped the relay with the ac relay cause they're the same and no change.
Any thing else I might be missing to check ?
This is getting frustrating !
Thanks for everyones time and advice I really do appreciate it.
 

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Perhaps check the ground to your fuel pump... It's near where the harness is connected on one of the frame rails (I think).

This is just a shot in the dark.. but a bad ground could affect the fuel pump and this is definitely an easy check.
 

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AstroWill said:
Slowly pinch off the return line and see if the pressure increases(but don't let it get above 75).
I'm going to see if my idle cleans up if I can increase the PSI in the system. Where to pinch the return line? At the nylon section? The FSM warns about "bending" these pipes too much -- so I suppose it doesn't take much to "pinch" these lines without damage. I suppose an inline ball valve or something could work but no need if it isn't necessary.

I'm only hashing this up because I sat in Stormy Daniels (CopperFireMist's other builder van) and it had the smoothest idle I'd ever felt in an Astro. I didn't test her PSI, but I know my 49 PSI at idle and 52 at KOEO is on a low-to-very-low side of the spec.
 

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Did you ever figure this out? I am having the same issue with my 03 Astro! Running the van was only at 53 psi.... Same with loss of oil pressure at stop and it stalls. Also, occasionally have a hard time starting. Thanks in advance!
 

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I have 2000 astro van but I am not a mechanic I do know a little about cars can I change the fuel regulator myself
As long one has the tools and can follow directions accurately, anyone can do it.
 
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