Backfire Nightmare
Thread Starter
Intermediate
Joined: Mar 2004
Posts: 46
Likes: 0
From: kalamazoo MI
Backfire Nightmare
I have a backfire through the exhaust problem.
It is present under load only. I can’t get it to backfire in the garage.
I put a mild cam in over the winter along with an intake. I have my timing set correctly 12 initial 32 total, and I’m currently testing with the vacuum advanced plugged. I richened the Quadrajet 2 jet sizes per Lars paper. I noticed it was running rich and the idle mixture screws had no effect on the idle quality. I looked into the carb with the timing light and fuel was dripping from the primary fuel ports. I would expect to see a mist. I then put the original jets back in the carb and check the float level again. I had the same backfire problem along with the fuel dripping. It seems to be running very rich. Is this common to the exhaust backfire? Also, I am considering changing to a lighter power piston spring. I tried testing the power piston, by pressing it down thru the fuel bowl vent, but I had no change in performance.
Any tips would be greatly appreciated.
Thanks
It is present under load only. I can’t get it to backfire in the garage.
I put a mild cam in over the winter along with an intake. I have my timing set correctly 12 initial 32 total, and I’m currently testing with the vacuum advanced plugged. I richened the Quadrajet 2 jet sizes per Lars paper. I noticed it was running rich and the idle mixture screws had no effect on the idle quality. I looked into the carb with the timing light and fuel was dripping from the primary fuel ports. I would expect to see a mist. I then put the original jets back in the carb and check the float level again. I had the same backfire problem along with the fuel dripping. It seems to be running very rich. Is this common to the exhaust backfire? Also, I am considering changing to a lighter power piston spring. I tried testing the power piston, by pressing it down thru the fuel bowl vent, but I had no change in performance.
Any tips would be greatly appreciated.
Thanks
Thread Starter
Intermediate
Joined: Mar 2004
Posts: 46
Likes: 0
From: kalamazoo MI
I'm confident timing is set correctly, and adjusting the carb doesn't have an effect. Anyone know if a mild cam would require a power piston spring change, or what else would cause the Quadrajet to run rich and backfire through the exhaust?
Thanks
Thanks
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
The unregulated fuel you see dripping in your carb is the problem in my opinion. Check the needle and seat that the float controls and make sure the small spring did not come off the float or the needle.
Good Luck and let us know what you find.
Good Luck and let us know what you find.
Thread Starter
Intermediate
Joined: Mar 2004
Posts: 46
Likes: 0
From: kalamazoo MI
Thanks, I'll pull it back apart and check the float when I get home.
Also, has anyone has a problem with the power piston sticking in its corresponding bore. Mine seems to function properly, but it is difficult to install/remove. Also, that plastic seal on top of the power piston is shot, but I don't think that in critical the it's function,
Sly, I've enjoyed you write-up on the T5 installation, how's the progress?
Also, has anyone has a problem with the power piston sticking in its corresponding bore. Mine seems to function properly, but it is difficult to install/remove. Also, that plastic seal on top of the power piston is shot, but I don't think that in critical the it's function,
Sly, I've enjoyed you write-up on the T5 installation, how's the progress?
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
Trans is in and working with a few small problems.
http://forums.corvetteforum.com/show....php?t=1685375
http://forums.corvetteforum.com/show....php?t=1685375
Last edited by sly vette; Apr 23, 2007 at 12:48 PM.
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Race Director
Joined: Mar 2006
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From: Florida
Thanks, I'll pull it back apart and check the float when I get home.
Also, has anyone has a problem with the power piston sticking in its corresponding bore. Mine seems to function properly, but it is difficult to install/remove. Also, that plastic seal on top of the power piston is shot, but I don't think that in critical the it's function,
Sly, I've enjoyed you write-up on the T5 installation, how's the progress?
Also, has anyone has a problem with the power piston sticking in its corresponding bore. Mine seems to function properly, but it is difficult to install/remove. Also, that plastic seal on top of the power piston is shot, but I don't think that in critical the it's function,
Sly, I've enjoyed you write-up on the T5 installation, how's the progress?
You can stake the phenolic washer very lightly.
