I'm at my last straw...
Thread Starter
Senior Member
Joined: Aug 1999
Posts: 950
Likes: 0
From: This spot right here --->*
Car: 2002 SOM z28
Engine: LS1
Transmission: T-56
I'm at my last straw...
<font face="Verdana, Arial" size="2">Originally posted by Biochem:
So I've pulled the needle, etc. and hit the whole thing with carb cleaner. I didn't notice anything obviously wrong when it was apart either. Float levels are so the fuel just barely trickles out when I rock the car (engine running) and I figure the needle/seats are good because gas is not shooting out. The psi is about 6-6 1/2 or so and I confirmed it with 2 gauges. The vacuum is about 13-14 and the idle is steady at 1000 in park and about 800 in drive. I've recently changed the power valve with a 6.5 rating and the jets are #68. I've sprayed the metering plate passages out a few times with carb cleaner and the choke works as it should as far as I can tell.
Now why the **** does the A/F gauge start off reading normal... then slowly read richer and richer? It does the same thing even with a new O2 sensor when it is warm. My plugs look OK I guess (not overly black and fouled) and the car runs OK, but the A/F gauge is basically worthless for determining anything. If it is accurate, then, after a few seconds in the normal range, I am running slightly rich (especially if I floor it) at all times. This would explain the gas smell and 15 mpg. Basically it goes nuts when I drive too... I think/hope it is supposed to go "way lean" when it really is super rich...
Any thoughts as to WTF is going on? It's always done this as far as I know/remember
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So I've pulled the needle, etc. and hit the whole thing with carb cleaner. I didn't notice anything obviously wrong when it was apart either. Float levels are so the fuel just barely trickles out when I rock the car (engine running) and I figure the needle/seats are good because gas is not shooting out. The psi is about 6-6 1/2 or so and I confirmed it with 2 gauges. The vacuum is about 13-14 and the idle is steady at 1000 in park and about 800 in drive. I've recently changed the power valve with a 6.5 rating and the jets are #68. I've sprayed the metering plate passages out a few times with carb cleaner and the choke works as it should as far as I can tell.
Now why the **** does the A/F gauge start off reading normal... then slowly read richer and richer? It does the same thing even with a new O2 sensor when it is warm. My plugs look OK I guess (not overly black and fouled) and the car runs OK, but the A/F gauge is basically worthless for determining anything. If it is accurate, then, after a few seconds in the normal range, I am running slightly rich (especially if I floor it) at all times. This would explain the gas smell and 15 mpg. Basically it goes nuts when I drive too... I think/hope it is supposed to go "way lean" when it really is super rich...
Any thoughts as to WTF is going on? It's always done this as far as I know/remember
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The car runs well, I guess, but I want to determine exactly what is the mixture (am I rich or not) so I can determine how much gas I need to add for nitrous. If I am not slightly rich, than this Autometer gauge is junk. If I am rich... how can I reduce the mixture? Any thoughts? Any questions... I know I've turned every screw at least once on this thing...
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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...
-=ICON Motorsports=-
Supreme Member
Joined: Jan 2001
Posts: 1,411
Likes: 3
From: Rock Hill, SC
Car: 1999 Pontiac T/A Firehawk
Engine: ***'s Engine
Transmission: T56
Something is loading up the carb with gas... I can give you one suggestion.
Check all the vacuum lines for the charcoal canister if you still have it. I had mine connected wrong and it was applying vacuum directly to the vent line from the tank... in essence, the carb was sucking gas vapors down ALL the time.
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"Beware he who would deny you access to information, for in his heart, he dreams himself your master"
'84 Black Camaro ZZ4 M5 (V-6 in a former life) -- street beast
'91 Medium Blue Metallic Z28 A4 (UB-HSTRY's old ride) -- currently broken
'99 Navy Blue Metallic Firehawk #120 M6 (99.44% stock) -- daily driver
Check all the vacuum lines for the charcoal canister if you still have it. I had mine connected wrong and it was applying vacuum directly to the vent line from the tank... in essence, the carb was sucking gas vapors down ALL the time.
------------------
"Beware he who would deny you access to information, for in his heart, he dreams himself your master"
'84 Black Camaro ZZ4 M5 (V-6 in a former life) -- street beast
'91 Medium Blue Metallic Z28 A4 (UB-HSTRY's old ride) -- currently broken
'99 Navy Blue Metallic Firehawk #120 M6 (99.44% stock) -- daily driver
Supreme Member
Joined: Jul 2001
Posts: 3,974
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From: Pueblo Co
Car: 1989 C4
Engine: L98
Transmission: 700r4
Axle/Gears: 307
This may not be what you want to hear but, RETURN IT!
I just bought a holley a week ago and the thing wouldent play and yes it was brand new.
I went through a big hassle to return it, I was even told I have old fuel and thats why it wouldent run
. I eventualy got a refund and went to another store and got another. It works fine now.
SSC
I just bought a holley a week ago and the thing wouldent play and yes it was brand new.
I went through a big hassle to return it, I was even told I have old fuel and thats why it wouldent run
. I eventualy got a refund and went to another store and got another. It works fine now.SSC
Thread Starter
Senior Member
Joined: Aug 1999
Posts: 950
Likes: 0
From: This spot right here --->*
Car: 2002 SOM z28
Engine: LS1
Transmission: T-56
Sorry, but returning it is not an option really. In fact, I'll take it to a professional carb guy to get this POS running right before I do that 
I still have the charcol canister and I am sure it isn't hooked up quite right... I'll check that too. I do notice though that I do not have that "whooshing" sound when I open the gas cap though (like it does on the rice car), so I can't imagine it is doing that. I will definately check though. In fact, I think I'm going to start off by capping off all the outlets to vacuum lines and see what is the guilty party this weekend... That will be the last one I hook up!
------------------
1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...
-=ICON Motorsports=-
I still have the charcol canister and I am sure it isn't hooked up quite right... I'll check that too. I do notice though that I do not have that "whooshing" sound when I open the gas cap though (like it does on the rice car), so I can't imagine it is doing that. I will definately check though. In fact, I think I'm going to start off by capping off all the outlets to vacuum lines and see what is the guilty party this weekend... That will be the last one I hook up!
------------------
1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...
-=ICON Motorsports=-
Supreme Member
Joined: Jan 2001
Posts: 1,411
Likes: 3
From: Rock Hill, SC
Car: 1999 Pontiac T/A Firehawk
Engine: ***'s Engine
Transmission: T56
Biochem,
when my charcoal canister was hooked up wrong, I got no woosh either. What I *did* get was a weird pressure releasing noise that turned out to be the vaccuum in the gas tank sucking air back through the vent line. I had that noise almost immediately after shutdown, though.
It really sounds like something is loading the carb up with gas slowly, and the most common culprit is something screwed up in the charcoal canister (EVAP) system. Either purging all the time or something else stupid.
when my charcoal canister was hooked up wrong, I got no woosh either. What I *did* get was a weird pressure releasing noise that turned out to be the vaccuum in the gas tank sucking air back through the vent line. I had that noise almost immediately after shutdown, though.
It really sounds like something is loading the carb up with gas slowly, and the most common culprit is something screwed up in the charcoal canister (EVAP) system. Either purging all the time or something else stupid.
Member
Joined: Oct 2000
Posts: 279
Likes: 0
From: Macon, Georgia
When I was young and hamfisted, I had the same thing happen to me. It was because I had overtorqued every screw on the carb and then torqued it down onto the manifold too hard. The carb body warped very nicely and was allowing lots of gas to leak straight into the engine. If you can't return the carb, try checking to make sure every mating surface is perfectly flat.
Thread Starter
Senior Member
Joined: Aug 1999
Posts: 950
Likes: 0
From: This spot right here --->*
Car: 2002 SOM z28
Engine: LS1
Transmission: T-56
I don't think over tightening the carb is my problem... I am pretty careful to make sure that I don't do that. It will be #2 on the list of things I check this weekend though! Thanks...
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Joined: Oct 1999
Posts: 270
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From: Phila. suburbs, PA, USA
Car: Pontiac Grand Prix GTP
Engine: 3.8L V6 SuperCharged
Hmmm... When I open my gas cap, most of the time it hisses like a *****!!! Does this mean something is wrong? I always thought it was just that the car is old and they just did that. Thanks
John
John