Need Help!! Fuel problem!!
Instructor
Joined: Jun 2005
Posts: 140
Likes: 0
From: Bovingdon Hertfordshire
Me Too !!
Guess what - I have exactly the same problem !!
It only seems to happen when the car is really hot, I have to do several 10s of miles before mine starts the kangaroo though.
I thought it was transmission also, but am also looking at fuel issues at this time, if you get a fix - tell me what it is PLEASE !
I have to drive a long way to get it do do it - but once it starts it's there pretty much all the time.
I have re-newed:
The metal line from pump to carb. (and then insulted it)
The paper filter in the carb.
The flexible hoses to the pump.
Checked that the Gas Tank Cap does breath (try that on yours) if you are pulling a vacuum in the tank that will cause starvation.
I'm waiting for a new pump (why is it so hard to get bits in the UK ?)
I guess if it still does it after all that then I've run out of ideas.
I'm guessing it's not spark fade, since if it was when the spark came back it would ignite the fuel which had been pumped into the exhaust causing a backfire - don't get that.
Anyway - if you solve it - please let me know how.
Yours,
Jeremy.
It only seems to happen when the car is really hot, I have to do several 10s of miles before mine starts the kangaroo though.
I thought it was transmission also, but am also looking at fuel issues at this time, if you get a fix - tell me what it is PLEASE !
I have to drive a long way to get it do do it - but once it starts it's there pretty much all the time.
I have re-newed:
The metal line from pump to carb. (and then insulted it)
The paper filter in the carb.
The flexible hoses to the pump.
Checked that the Gas Tank Cap does breath (try that on yours) if you are pulling a vacuum in the tank that will cause starvation.
I'm waiting for a new pump (why is it so hard to get bits in the UK ?)
I guess if it still does it after all that then I've run out of ideas.
I'm guessing it's not spark fade, since if it was when the spark came back it would ignite the fuel which had been pumped into the exhaust causing a backfire - don't get that.
Anyway - if you solve it - please let me know how.
Yours,
Jeremy.
Melting Slicks
Joined: Feb 2002
Posts: 2,625
Likes: 0
From: Cut n Shoot TX
heres a link to a thread about my problem which seems to be the same problem as you. its in the works
http://forums.corvetteforum.com/show...post1560158358
http://forums.corvetteforum.com/show...post1560158358
Let me know what works for you.
Melting Slicks
Joined: Feb 2002
Posts: 2,625
Likes: 0
From: Cut n Shoot TX
Burning Brakes
Joined: Oct 2004
Posts: 920
Likes: 1
From: Shelby Township Michigan
I have had a similar experience and can tell you what I did. I found fuel leaking from the carburetor accelerator pump, so I decided to rebuild it. Lars gave me the part number of the preferred rebuild kit, new float, paper fuel filter and vacuum pull off (1972 Quadrajet).
The rebuild was not too hard at all and allowed me to clean up the carb and intake. I adjusted my timing for 36 degrees advance at 2800 rpm and so far, I have not experienced the problem. The car has a solid acceleration from a dead stop and when I stomp on it, she jumps.
Good luck,
Dino
The rebuild was not too hard at all and allowed me to clean up the carb and intake. I adjusted my timing for 36 degrees advance at 2800 rpm and so far, I have not experienced the problem. The car has a solid acceleration from a dead stop and when I stomp on it, she jumps.
Good luck,
Dino
Racer
Joined: Mar 2006
Posts: 366
Likes: 1
From: Houston Texas
From one of Lars' papers at the following link:
http://www.corvettefaq.com/c3/QJetTuningPaper.doc
"You have to pull the top of the carb off to set the float level. With the top removed, remove the big phenolic spacer that covers the area around the needle/seat. Hold the float hinge clip firmly seated and push down lightly on the float where it contacts the needle. Measure from the top of the float bowl to the top of the float at the rear edge of the float. Float level should be .375” for a street-driven car using a 1968 – 1974 carb; you can run it at .250” for racing. Early Q-Jets (1968-1972) can be successfully run on the street with the high float level, but you may see some fuel saturation of the air horn gasket with associated gas fumes. Later carbs (1975 and newer) do not run well in street applications with the high float level – run the 1975 + carbs at .420” on the float level. Adjust the float level by removing the float and bending its lever arm. Never raise the float level by forcing the float against the needle/seat to bend it – this will damage the needle."
For the oem type float, if it becomes impregnated with fuel, it does not 'float' all of the way up which has the same effect of setting too low.
If you contact Lars directly, he can send you the latest update to his qjet tuning paper.
http://www.corvettefaq.com/c3/QJetTuningPaper.doc
"You have to pull the top of the carb off to set the float level. With the top removed, remove the big phenolic spacer that covers the area around the needle/seat. Hold the float hinge clip firmly seated and push down lightly on the float where it contacts the needle. Measure from the top of the float bowl to the top of the float at the rear edge of the float. Float level should be .375” for a street-driven car using a 1968 – 1974 carb; you can run it at .250” for racing. Early Q-Jets (1968-1972) can be successfully run on the street with the high float level, but you may see some fuel saturation of the air horn gasket with associated gas fumes. Later carbs (1975 and newer) do not run well in street applications with the high float level – run the 1975 + carbs at .420” on the float level. Adjust the float level by removing the float and bending its lever arm. Never raise the float level by forcing the float against the needle/seat to bend it – this will damage the needle."
For the oem type float, if it becomes impregnated with fuel, it does not 'float' all of the way up which has the same effect of setting too low.
If you contact Lars directly, he can send you the latest update to his qjet tuning paper.
Last edited by justanotherdoe; May 9, 2007 at 02:26 PM.
Melting Slicks
Joined: Feb 2002
Posts: 2,625
Likes: 0
From: Cut n Shoot TX
I may have gotten lucky! Found a 10''small rubber hose from the steel line running from the tank to the inlet of the fuel pump has a major kink! Do not know how long this has been like this, but this will be my first plan of attack, to change out that small line with a 10'' piece of fresh rubber fuel line. If that does not work, then I will try changing the carb fuel filter. i want to take baby steps first before removing the tank and checking the sock.
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Melting Slicks
Joined: Feb 2002
Posts: 2,625
Likes: 0
From: Cut n Shoot TX
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Racer
Joined: Oct 2004
Posts: 318
Likes: 0
I had the same problem. I dropped the tank and replaced the strainer inside. You can shine a flashlight in the fill hole and see if the strainer looks in rough shape, easiest when tank is on "E" or close to it. My car runs much better now, all I need to do now is replace the plug wires. Its always something.
Dave
Dave
CF JASOC Member
Joined: Feb 2006
Posts: 8,040
Likes: 34
From: Downtown Annapolis, MD. The Future is where we all have to live. Let's not screw it up.
St. Jude Donor '08-'09-'10-'11
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
I'll put my money on the kinked hose. Sounds like just the kind of restriction that would cause your problem. Put a clamp on the hose just after the tank outlet and cut it after the clamp. This will keep you from losing fuel. Then you can put the new section in with a "jumper union" from the old hose to the new section. Secure it, release the clamp and put the pedal to the metal!
Melting Slicks
Joined: Feb 2002
Posts: 2,625
Likes: 0
From: Cut n Shoot TX
I'll put my money on the kinked hose. Sounds like just the kind of restriction that would cause your problem. Put a clamp on the hose just after the tank outlet and cut it after the clamp. This will keep you from losing fuel. Then you can put the new section in with a "jumper union" from the old hose to the new section. Secure it, release the clamp and put the pedal to the metal!
2nd Gear
Joined: May 2007
Posts: 2
Likes: 0
Fuel Starvation
Hey guys. I'm new here so bear with me. I have a '82 which is having the same type of spitting and sputtering going at hi way speed. At one time when I applied half throttle is when the sputtering would start. Now its started at cruising speed. I'm leaning towards the in line fuel filter. But, can I get access to the tank sock through the fuel cap area?
Thanks.
Thanks.
Thread Starter
TheCorvetteBen
Joined: Feb 2007
Posts: 4,987
Likes: 144
From: Van Alstyne, TX
Well i changed out the fuel pump and it still does the jumping thing. I think the next plan would be to start replacing the fuel lines
Race Director
Joined: Oct 2000
Posts: 15,065
Likes: 79
From: central FL, near the beach.
these problems are easy to fix.
1st i put on my fuel pump tester, tape it to windshield and test drive.
for those w/catalytic converter, i check the psi in front of it, if #1 isn't it.
In 1970 i was 17 and put an ad in the paper WILL FIX ANY ENGINE PROBLEM $10 OR NO CHARGE. Fixed a brand new chevy in 15 min. that the guy took in 5 or 6 times to the dealer. LOL
1st i put on my fuel pump tester, tape it to windshield and test drive.
for those w/catalytic converter, i check the psi in front of it, if #1 isn't it.
In 1970 i was 17 and put an ad in the paper WILL FIX ANY ENGINE PROBLEM $10 OR NO CHARGE. Fixed a brand new chevy in 15 min. that the guy took in 5 or 6 times to the dealer. LOL
Advanced
Joined: May 2007
Posts: 79
Likes: 1
From: Rough and Ready California
I'm having the same problem, every once in a while the car bucks like a bull for a few seconds then returns to normal. Usually happens when I put my foot to it, but not all the time. Occasionally the car doesn't want to start easily and it seems to be for the same reason, no fuel! I followed my fuel line back to the tank and didn't see any kinks or leaks, and my filter was clean.
Matt Gruber--- If you were close by I'd gladly pay you the 10 bucks!
Matt Gruber--- If you were close by I'd gladly pay you the 10 bucks!
