Valve adjustment with stud girdles?
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by big_G
A fuel pressure gauge will rule out alot. I tape one to the outside of a customers windshield when diagnosing your type of problem The way it falls off way down the track says it's not the accelerator pumps, your way past their responsibilities.
Well, maybe I should get a second opinion on that.. I'm 99% sure that the carb is the problem.. If I could just find somebody that has a extra 80514 Holley laying around that I could borrow to make sure.. I was already thinking in buying another 80514 but that carb is friggin expensive...
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Did you figure out how to do it ? I take my stud girdles off put ithem on the bench, adjust the valves and put the girdles back on again 
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by MotorHead
Did you figure out how to do it ? I take my stud girdles off put ithem on the bench, adjust the valves and put the girdles back on again
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St. Jude Donor '03, '06, '17
Burning Brakes
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From: Finland
Originally Posted by GrandSportC3
yup, it sounds like it but I had plenty of fuel in the tank... Too bad that I don't have a fuel pressure gauge that can be seen from the inside...
That hesitation also happens when I rev the car up at idle, so it's not just under load...
That hesitation also happens when I rev the car up at idle, so it's not just under load...
Float levels right?
Might be small dirt inside carb...?
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St. Jude Donor '03, '06, '17
Originally Posted by Vesa
Fuel filter new?
Float levels right?
Might be small dirt inside carb...?
Float levels right?
Might be small dirt inside carb...?
The carb just came back from the carb shop and they said that they tested it after they changed the needles and seats and the power valves..
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From: Waterloo ontario Canada
Originally Posted by gkull
Norval - I also see that even Crane thinks big block guy are kind of stupid!
They have to spell out what is exhaust and intake!
They have to spell out what is exhaust and intake!
Yes we big block boys are a little slow
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Originally Posted by GrandSportC3
You don't have hesitation the motor about shut down. If you have a multi spark box try removing it.
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by gkull
You don't have hesitation the motor about shut down. If you have a multi spark box try removing it.
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From: Geneva Ohio
Sounds to me that you have a fuel delivery problem. Not the carb. With your setup you need at least a 1/2" fuel line, a good fuel pump (280GPH), a free flowing low restriction two port fuel pressure regulator with gauge. A Wide band O2 sensor with A/F gauge is also a good investment to dial in the setup.
You need to have a nice light tan plug color to have right mixture, not grey or white. Bear in mind that unless you shut down and pull plugs right at the end of a pass they will change color down the return road to the trailer.
You will also need 7 to 9 psi. fuel pressure all the way down the track or the car will start to miss after about 150 feet.
You might try to increase the pressure at the regulator a little bit and see if there is any change. But without a gauge it is only guess work.
You need to have a nice light tan plug color to have right mixture, not grey or white. Bear in mind that unless you shut down and pull plugs right at the end of a pass they will change color down the return road to the trailer.
You will also need 7 to 9 psi. fuel pressure all the way down the track or the car will start to miss after about 150 feet.
You might try to increase the pressure at the regulator a little bit and see if there is any change. But without a gauge it is only guess work.
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by red79vette454
Sounds to me that you have a fuel delivery problem. Not the carb. With your setup you need at least a 1/2" fuel line, a good fuel pump (280GPH), a free flowing low restriction two port fuel pressure regulator with gauge. A Wide band O2 sensor with A/F gauge is also a good investment to dial in the setup.
You need to have a nice light tan plug color to have right mixture, not grey or white. Bear in mind that unless you shut down and pull plugs right at the end of a pass they will change color down the return road to the trailer.
You will also need 7 to 9 psi. fuel pressure all the way down the track or the car will start to miss after about 150 feet.
You might try to increase the pressure at the regulator a little bit and see if there is any change. But without a gauge it is only guess work.
You need to have a nice light tan plug color to have right mixture, not grey or white. Bear in mind that unless you shut down and pull plugs right at the end of a pass they will change color down the return road to the trailer.
You will also need 7 to 9 psi. fuel pressure all the way down the track or the car will start to miss after about 150 feet.
You might try to increase the pressure at the regulator a little bit and see if there is any change. But without a gauge it is only guess work.
Considering the light gray color, I'm going to change the jetting of the carb.. Right now I have 84 primary and 84 secondary jets.. I might step up to 88 on the secondary side.. That's actually the way the 1000 cfm carb comes from the factory. The engine builder jetted it down to 84 on the secondary side. However, I've put a bigger intake and a scoop on the car which will change the A/F..
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From: Reno Nevada
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It's been my experience that electric fuel pumps have a short life span. I've replaced the impellar blades in mine before. I just mention this because you ask why?
Safety Car
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From: San Antonio TX
I think you'll find this problem, as George wrote, in the ignition and occuring most prominently at your torque peak.
Here's why I think that: You are past your enrichment circuits, the boosters are flowing, the car isn't falling on its face, and you haven't melted any pistons.
The best way to tell is to record the ignition secondary with a dual trace lab scope and watch for the glitchs. There may be initiation voltage but no firing line. I'd make sure your usual suspects (cap, rotor, wires, coil, ignition module, and amplifier) are up to snuff.
Here's why I think that: You are past your enrichment circuits, the boosters are flowing, the car isn't falling on its face, and you haven't melted any pistons.
The best way to tell is to record the ignition secondary with a dual trace lab scope and watch for the glitchs. There may be initiation voltage but no firing line. I'd make sure your usual suspects (cap, rotor, wires, coil, ignition module, and amplifier) are up to snuff.
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by gkull
It's been my experience that electric fuel pumps have a short life span. I've replaced the impellar blades in mine before. I just mention this because you ask why?
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St. Jude Donor '03, '06, '17
Originally Posted by gerry72
I think you'll find this problem, as George wrote, in the ignition and occuring most prominently at your torque peak.
Here's why I think that: You are past your enrichment circuits, the boosters are flowing, the car isn't falling on its face, and you haven't melted any pistons.
The best way to tell is to record the ignition secondary with a dual trace lab scope and watch for the glitchs. There may be initiation voltage but no firing line. I'd make sure your usual suspects (cap, rotor, wires, coil, ignition module, and amplifier) are up to snuff.
Here's why I think that: You are past your enrichment circuits, the boosters are flowing, the car isn't falling on its face, and you haven't melted any pistons.
The best way to tell is to record the ignition secondary with a dual trace lab scope and watch for the glitchs. There may be initiation voltage but no firing line. I'd make sure your usual suspects (cap, rotor, wires, coil, ignition module, and amplifier) are up to snuff.
1) For now I'm gonna try to bypass the ignition box.
2) gonna watch the voltage while reving up if there's a electrical problem
3) gonna watch the fuel pressure while reving up
4) gonna re-jet the carb
If none of those things will be successful, I'll bring the car to a mechanic to find the problem..
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From: Geneva Ohio
Originally Posted by gkull
It's been my experience that electric fuel pumps have a short life span. I've replaced the impellar blades in mine before. I just mention this because you ask why?
The fuel system that you have now maybe actually keeping you from the "10" that you are seeking.
A low volume pump and 5/16 or 3/8 fuel line cannot possibly feed a 600 HP motor.
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St. Jude Donor '03, '06, '17
Originally Posted by red79vette454
As you go faster please realize that fuel demand increases.
The fuel system that you have now maybe actually keeping you from the "10" that you are seeking.
A low volume pump and 5/16 or 3/8 fuel line cannot possibly feed a 600 HP motor.
I'm gonna upgrade to #8 braided line soon...but my current problem can't be related to that because the car was running good before with the identical setup.. Didn't change anything since the car ran problem free.. I had my best summer ET and the car ran great.. After that pass, the car never ran right without any changes...
Got home too late tonight to work on the car.. Now it's too late to start her up..
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From: FRANKLIN GA
Originally Posted by red79vette454
You need to have a nice light tan plug color to have right mixture, not grey or white. Bear in mind that unless you shut down and pull plugs right at the end of a pass they will change color down the return road to the trailer.
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St. Jude Donor '03, '06, '17
I finally found out what caused my hesitation/miss issue...
It was a wiring issue on the distributor.. According to the Crane HI6R Ignition wiring diagram, the ground port on the distributor connects to the ground of the HEI module.. However, it doesn't show that it also needs to be connected to actual ground... I was at the track today (at the Florida Corvette Challenge) and the car ran like crap on my first pass...
Looking at the HEI wiring on Isoceless's car, I noticed that there was a wire running from the GND port on the HEI to the intake.
I connected the GND port on the HEI to ground from the valve cover bolts and made another pass........and the car ran great
I ended up getting into the Final of the Corvette Challenge whrere I lost by only .01 seconds.... Got a nice tropy, price money and a runner up cap
My R/T's were great today.. .02, .047, .072, .022, .059 and .082
My best package today was a .05 package!!
Ran a 11.153 on a 11.15 dial with a .047 light
It was a wiring issue on the distributor.. According to the Crane HI6R Ignition wiring diagram, the ground port on the distributor connects to the ground of the HEI module.. However, it doesn't show that it also needs to be connected to actual ground... I was at the track today (at the Florida Corvette Challenge) and the car ran like crap on my first pass...
Looking at the HEI wiring on Isoceless's car, I noticed that there was a wire running from the GND port on the HEI to the intake.
I connected the GND port on the HEI to ground from the valve cover bolts and made another pass........and the car ran great
I ended up getting into the Final of the Corvette Challenge whrere I lost by only .01 seconds.... Got a nice tropy, price money and a runner up cap
My R/T's were great today.. .02, .047, .072, .022, .059 and .082
My best package today was a .05 package!!
Ran a 11.153 on a 11.15 dial with a .047 light
Last edited by GrandSportC3; Sep 25, 2005 at 01:40 AM.
