could be the cats, do you hear any rattling sounds?
Fuel pressure-What should it be?
Thread Starter
Pro
Joined: Mar 1999
Posts: 532
Likes: 0
From: Cleveland Ohio
Fuel pressure-What should it be?
I replaced the fuel filter today (91-L98) in hopes that it would remove my run out of gas feeling. While at it I attached a fuel pressure gauge to the fuel rail and taped it to the windshield.
At idle it's around 35psi. While accelerating it hovers around 40 and with a down shift it jumps to around 43-45.
I can now pull to 5 grand, slowly, where it use to go flat around 4 but it continues to feel like I'm pulling a trailer. Just NO guts.
Am I missing something. Any suggestions appreciated! Oh yeah, what should those pressures be? Thanks, Frank
At idle it's around 35psi. While accelerating it hovers around 40 and with a down shift it jumps to around 43-45.
I can now pull to 5 grand, slowly, where it use to go flat around 4 but it continues to feel like I'm pulling a trailer. Just NO guts.
Am I missing something. Any suggestions appreciated! Oh yeah, what should those pressures be? Thanks, Frank
Racer
Joined: Aug 2004
Posts: 379
Likes: 170
From: Buffalo Grove IL
Those fuel pressure numbers are right where they should be.
As far as what could be causing your problems, oh boy... clogged cats? massively retarded ignition timing?
Any codes showing? Can you get the car on a scanner so you can see what the ECM is doing?
Ben
As far as what could be causing your problems, oh boy... clogged cats? massively retarded ignition timing?
Any codes showing? Can you get the car on a scanner so you can see what the ECM is doing?
Ben
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Its been sitting..get yourself some SeaFoam..skip the directions...put 1/2 in fuel tank, put the other 1/2 through the brake booster vac line..
keep the RPMs up between 1500-1800, it'll probably smoke like hell, don't worry, and it may throw an 02 code..sometimes it puts a mist on the sensor..don't worry, it will burn off and just disconnect the negative battery terminal for a few minutes, that will clear the code. After sitting that long..you probably have some water in the fuel system...SeaFoam will take care of it.
keep the RPMs up between 1500-1800, it'll probably smoke like hell, don't worry, and it may throw an 02 code..sometimes it puts a mist on the sensor..don't worry, it will burn off and just disconnect the negative battery terminal for a few minutes, that will clear the code. After sitting that long..you probably have some water in the fuel system...SeaFoam will take care of it.
Thread Starter
Pro
Joined: Mar 1999
Posts: 532
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From: Cleveland Ohio
Thanks Guys, Rick, Good suggestion but I put it away with a full tank which didn't leave much room for condensation so I'm a little doubtful but will keep it in mind. That plus I've had this problem since midway through the 05 driving season, makes me think it's elsewhere, other then water.
Ben, No scanner available and no codes thrown (paper clip method). I'll check the timing but your suggestion of blocked cats might be on the number. I think I've eliminated fuel with the normal pump pressure and the new filter. The injectors are/were new a couple of thousand miles ago. Admittedly they're Accel but I can't believe they all went bad at once. I can hear the car sucking air when I get on it so maybe it's time to think a new exhaust system.
I see Corvette Central has a complete, track only system, less mufflers for around $250. With the way these L98's are bottled up maybe that's the next part to toss at the problem.
It will probably increase the sound level some but should open the exhaust up.
Is there any way to test the exhaust system for clogging up cats?
Thanks, Frank
Ben, No scanner available and no codes thrown (paper clip method). I'll check the timing but your suggestion of blocked cats might be on the number. I think I've eliminated fuel with the normal pump pressure and the new filter. The injectors are/were new a couple of thousand miles ago. Admittedly they're Accel but I can't believe they all went bad at once. I can hear the car sucking air when I get on it so maybe it's time to think a new exhaust system.
I see Corvette Central has a complete, track only system, less mufflers for around $250. With the way these L98's are bottled up maybe that's the next part to toss at the problem.
It will probably increase the sound level some but should open the exhaust up.
Is there any way to test the exhaust system for clogging up cats?
Thanks, Frank
Last edited by Frank C; May 18, 2006 at 10:04 AM.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
That is the most common way. If you have precats infront of the cat they too can come loose and block the cat or if you hit something in the road to bend the cat and cause a restriction to exhaust flow. IMO
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Thread Starter
Pro
Joined: Mar 1999
Posts: 532
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From: Cleveland Ohio
I don't recall hearing any rattling sounds but, I'll check. Next time it's on the lift I'll whack both cats and the middle one, whether it's a cat or a resonator, It'll get the rubber treatment. Thanks, Frank
