Carburetor issues...
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Carburetor issues...
I went to the track last Thursday and the car flooded when I was in line for my 2nd pass.. Somehow got the car started again and got it on the trailer. It ran like crap. Checked the plugs and they indicate flooding (plugs are black but used to be light grey before).
That's the 3rd time that I had the same issues with the carb. Seems like about every 40 passes, I need new needle&seats and new power valves. I'm only running about 7 psi of fuel pressure. That should be acceptable - right? According to Holley, you can run up to 7 psi of fuel pressure without a problem.. Oh well... Gonna drop off the carb at the shop tomorrow morning so that they can change the power valves and needle & seats.. I wonder how difficult it is to change them myself? Is it a lot of work? Anyway.. I want to go racing tomorrow, so I'll have somebody do it for me tomorrow, but for the future, I want to be able to change them myself. Detailed instructions with pics would be great!
Is there anything that could cause those parts to go bad that quickly?
BTW - it's a Holley 4150 HP series carb (part number 80514 - 1000 cfm)
That's the 3rd time that I had the same issues with the carb. Seems like about every 40 passes, I need new needle&seats and new power valves. I'm only running about 7 psi of fuel pressure. That should be acceptable - right? According to Holley, you can run up to 7 psi of fuel pressure without a problem.. Oh well... Gonna drop off the carb at the shop tomorrow morning so that they can change the power valves and needle & seats.. I wonder how difficult it is to change them myself? Is it a lot of work? Anyway.. I want to go racing tomorrow, so I'll have somebody do it for me tomorrow, but for the future, I want to be able to change them myself. Detailed instructions with pics would be great!
Is there anything that could cause those parts to go bad that quickly?
BTW - it's a Holley 4150 HP series carb (part number 80514 - 1000 cfm)
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Sounds like you are suffering from the notorious "trash in the needle and seat" syndrome. Holleys are notorious for this. You don't need to pay someone to fix this. The needle and seat are under that big flat head screwdrive type screw on the front and rear bowls. Loosen the screw and and back the nut out of the bowl, pull the needle and seat and blow them out with compressed air. Now put them back in with same number of turns so the floats will be at the same level.
If it is still flooding then you could have a blown power valve, another easy fix, you can even do it on the car. Take one of the lower bowl bolts out and let the gas drain into a little cup. Remove the bowl, unscrew the power valve and replace it, easy
If it is still flooding then you could have a blown power valve, another easy fix, you can even do it on the car. Take one of the lower bowl bolts out and let the gas drain into a little cup. Remove the bowl, unscrew the power valve and replace it, easy
Safety Car
Joined: Aug 2001
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Yes it is really easy to check the needle and seat. That is what the sight plug on the side of the carb is for. If you have an electric fuel pump screw the needle and seat down and good ways, turn the pump on, and then slowy raise the needle and seat (screw it in the opposite direction, counter clock wise), when fuel starts to dribble out of the sight plug you are good to go. You are actually adjusting the float level.
Do you have a good fuel filter on the car? I also filter my gas when I put it into my race containers.
Do you have a good fuel filter on the car? I also filter my gas when I put it into my race containers.
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Thanks for the info!
However, I had my fuel bowls off and I can't see the power valve.. Doesn't the main body have to come off to access it?
The only things that I can see with the fuel bowls off is the jets...
Well, I won't be able to do it myself today anyways due to lack of time. We had our first cool front yesterday and we have some drier air right now (eve though it's still hot - 90 for the high and 70 for the low). If the car will run ok, I should be in the 10.60's or even 10.50's tonight.. I really don't want to miss out on the lower humidity tonight.
I think that lack of filtration could be part of my problem. I'm only running one fuel filter before the pump and none from the pump to the carb. I'll add one later.
However, I had my fuel bowls off and I can't see the power valve.. Doesn't the main body have to come off to access it?
The only things that I can see with the fuel bowls off is the jets...
Well, I won't be able to do it myself today anyways due to lack of time. We had our first cool front yesterday and we have some drier air right now (eve though it's still hot - 90 for the high and 70 for the low). If the car will run ok, I should be in the 10.60's or even 10.50's tonight.. I really don't want to miss out on the lower humidity tonight.
I think that lack of filtration could be part of my problem. I'm only running one fuel filter before the pump and none from the pump to the carb. I'll add one later.
Drifting
Joined: Jan 2006
Posts: 1,832
Likes: 38
From: Cedar,BC
You need to go one step further.After you remove the bowl,the metering plate is next,it will come off with a slight rap or gentle pry with a screwdriver.The power valve is screwed into the backside of the plate.
Melting Slicks
Joined: Aug 1999
Posts: 3,123
Likes: 13
From: Hollywood, Florida
Originally Posted by tfi racing
You need to go one step further.After you remove the bowl,the metering plate is next,it will come off with a slight rap or gentle pry with a screwdriver.The power valve is screwed into the backside of the plate.
Next time, it will be an easy repair.
GOOD LUCK OLLIE, and hope to see you in the 10.50's
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Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Originally Posted by shoptek
Next time, it will be an easy repair.
GOOD LUCK OLLIE, and hope to see you in the 10.50's
Marc! How is everything?
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Originally Posted by comp
yep , and add the second filter
Race Director
Joined: Mar 2006
Posts: 14,112
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From: Florida
Here is a link to a inline. Got mine for 25.00 shipped. Just do a search and bid on a cheaper auction.
http://cgi.ebay.com/ebaymotors/Edelb...QQcmdZViewItem
Mine is a 10 micron and is good for fuel injectors too. 100 microns may be a bit porous.
http://cgi.ebay.com/ebaymotors/Edelb...QQcmdZViewItem
Mine is a 10 micron and is good for fuel injectors too. 100 microns may be a bit porous.
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Originally Posted by noonie
Here is a link to a inline. Got mine for 25.00 shipped. Just do a search and bid on a cheaper auction.
http://cgi.ebay.com/ebaymotors/Edelb...QQcmdZViewItem
Mine is a 10 micron and is good for fuel injectors too. 100 microns may be a bit porous.
http://cgi.ebay.com/ebaymotors/Edelb...QQcmdZViewItem
Mine is a 10 micron and is good for fuel injectors too. 100 microns may be a bit porous.