fuel issue with quadrajet
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From: Galveston... well, Santa Fe Texas
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fuel issue with quadrajet
you C3's are really helpful on the Carb stuff... so here we go again
last time I drove my 84 it kept dying on me. The Crossfire was replaced with a Quadrajet (off of a 1986 Dodge something)
I finally got around to looking, thinking the fuel filter was clogged, I decided to start there... I'm 100% positive it's not the fuel filter.
notice anything missing?
and further down the line, it does this:
nice, right?
guess it's time to get some fuel lines
question: the current fuel line is 1/4 inch... do I keep the same diameter, or can I go bigger. I also think I'm going to go with the steel-braided stuff vs. the hydraulic lines, and just replace all the way to the tank.
last time I drove my 84 it kept dying on me. The Crossfire was replaced with a Quadrajet (off of a 1986 Dodge something)
I finally got around to looking, thinking the fuel filter was clogged, I decided to start there... I'm 100% positive it's not the fuel filter.
notice anything missing?
and further down the line, it does this:
nice, right?
guess it's time to get some fuel lines
question: the current fuel line is 1/4 inch... do I keep the same diameter, or can I go bigger. I also think I'm going to go with the steel-braided stuff vs. the hydraulic lines, and just replace all the way to the tank.
Last edited by MonteHall; Jun 30, 2011 at 11:58 AM.
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
wait a minute here.....you said 84 so you had a fuel injection system.....what kind of pressure does that run on? most new FI units use high pressure lines....i wonder if the line was crimped to slow the pressure and flow? do you know what kind of fuel pump you have?
on a quadrajet the fuel filter may be in the carb...under the last nut from the fuel line its an inline filter mounted in the carb housing, not sure if dodge did it differently
on a quadrajet the fuel filter may be in the carb...under the last nut from the fuel line its an inline filter mounted in the carb housing, not sure if dodge did it differently
Last edited by bobs77vet; Jun 24, 2011 at 07:21 PM.
Burning Brakes
Joined: May 2008
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From: Stratford Ontario
wait a minute here.....you said 84 so you had a fuel injection system.....what kind of pressure does that run on? most new FI units use high pressure lines....i wonder if the line was crimped to slow the pressure and flow? do you know what kind of fuel pump you have?
on a quadrajet the fuel filter may be in the carb...under the last nut from the fuel line its an inline filter mounted in the carb housing, not sure if dodge did it differently
on a quadrajet the fuel filter may be in the carb...under the last nut from the fuel line its an inline filter mounted in the carb housing, not sure if dodge did it differently
Thread Starter
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From: Galveston... well, Santa Fe Texas
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St. Donor '03 & '06
wouldn't crimping it just drop the volume and not the pressure... if anything, pressure would increase (think thumb over garden hose)
The original FI pump is not wired up, however.
The original FI pump is not wired up, however.
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From: Galveston... well, Santa Fe Texas
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St. Donor '03 & '06
Thread Starter
Team Owner
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From: Galveston... well, Santa Fe Texas
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St. Donor '03 & '06
I went out and pulled the fuel pump.
it's really clean, and the part number (6441376) points to an OPEL Kadett or Volvo (mfr is AC). The Volvo that used it was a fuel injected I4.
I did run a line from the top of the pump to a container outside the car I cranked the car a few time and I got a little stream of gas, but it definitely wasn't 30 psi.
it's really clean, and the part number (6441376) points to an OPEL Kadett or Volvo (mfr is AC). The Volvo that used it was a fuel injected I4.
I did run a line from the top of the pump to a container outside the car I cranked the car a few time and I got a little stream of gas, but it definitely wasn't 30 psi.
Racer
Joined: Oct 2006
Posts: 396
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From: Buffalo New York
The cross fire fuel injection system is a throttle body system. I'm pretty sure that the fuel pump delivers much less pressure than a tpi system. If it's too much pressure, you would flood the carb.
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Le Mans Master
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From: eastern NC
I went out and pulled the fuel pump.
it's really clean, and the part number (6441376) points to an OPEL Kadett or Volvo (mfr is AC). The Volvo that used it was a fuel injected I4.
I did run a line from the top of the pump to a container outside the car I cranked the car a few time and I got a little stream of gas, but it definitely wasn't 30 psi.
it's really clean, and the part number (6441376) points to an OPEL Kadett or Volvo (mfr is AC). The Volvo that used it was a fuel injected I4.
I did run a line from the top of the pump to a container outside the car I cranked the car a few time and I got a little stream of gas, but it definitely wasn't 30 psi.
I don't recall if you actually said that you were running an electric pump or a mechanical pump on the block to your Quadrajet. If you are running the original electrical pump and it is pushing 14 psi, that will definitely overpower the needle valve in a Quadrajet.
Please let us know what exactly you are running for a fuel system. That will help us to help you diagnose your problem.
Good luck... GUSTO
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From: Galveston... well, Santa Fe Texas
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TBI fuel pressure should be 14 psi, but that is in a closed system, not from an open line into a container. An open line into a container with no restriction is only going to tell you the volume the pump is capable of, not tell you the pressure it is generating.
I don't recall if you actually said that you were running an electric pump or a mechanical pump on the block to your Quadrajet. If you are running the original electrical pump and it is pushing 14 psi, that will definitely overpower the needle valve in a Quadrajet.
Please let us know what exactly you are running for a fuel system. That will help us to help you diagnose your problem.
Good luck... GUSTO
I don't recall if you actually said that you were running an electric pump or a mechanical pump on the block to your Quadrajet. If you are running the original electrical pump and it is pushing 14 psi, that will definitely overpower the needle valve in a Quadrajet.
Please let us know what exactly you are running for a fuel system. That will help us to help you diagnose your problem.
Good luck... GUSTO
here's a pic.
The little bag-filter thing on the bottom of the pump was dirty.
it runs fine with the exception of last Wed when it started coughing... and I haven't driven it since
Last edited by MonteHall; Jun 25, 2011 at 04:09 PM.
Le Mans Master
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From: eastern NC
I also think that just from the view of the Quadrajet we have, you should consider at the least rebuilding it. Since it isn't really a Chevrolet or a Corvette Quadrajet, you might even consider replacing it with one from a Chevrolet or Corvette. I would also recommend changing out the fuel line to the carb with a solid metal line, at least down to the chassis.
Good luck and please let us know how this turns out.
GUSTO
Burning Brakes
Joined: Mar 2010
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From: Valdosta Georgia
I agree. The 84 X-Fire should have a return line already run. I'd get a pressure regulator with return and set that at the pressure necessary for the Q-Jet. I think it would be a good idea to replace that crimped line while you are there.
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I plan on rebuilding it with a kit from Cliff's. When I talked to him, he said the fact the it came off a Dodge really shouldn't matter, especially since it did run fine.
There already is a return line running in the tank and when I pulled it off to pull the pump, there was fresh gas in the line.
my current plan is to trace the whole fuel line and make sure it's not damaged anywhere else, then pick up a length of 1/4 rigid fuel line and start at the carb and redo the line as far as the pre-made length with get me.
There already is a return line running in the tank and when I pulled it off to pull the pump, there was fresh gas in the line.
my current plan is to trace the whole fuel line and make sure it's not damaged anywhere else, then pick up a length of 1/4 rigid fuel line and start at the carb and redo the line as far as the pre-made length with get me.
Le Mans Master
Joined: Sep 2003
Posts: 8,812
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From: eastern NC
I plan on rebuilding it with a kit from Cliff's. When I talked to him, he said the fact the it came off a Dodge really shouldn't matter, especially since it did run fine.
There already is a return line running in the tank and when I pulled it off to pull the pump, there was fresh gas in the line.
my current plan is to trace the whole fuel line and make sure it's not damaged anywhere else, then pick up a length of 1/4 rigid fuel line and start at the carb and redo the line as far as the pre-made length with get me.
There already is a return line running in the tank and when I pulled it off to pull the pump, there was fresh gas in the line.
my current plan is to trace the whole fuel line and make sure it's not damaged anywhere else, then pick up a length of 1/4 rigid fuel line and start at the carb and redo the line as far as the pre-made length with get me.
Gonna rebuild it?
Good luck... GUSTO
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ok... so I got the battery charged up. and it fired right up... kinda.
If I revved it, it would rev up, but at random times, I would hear alot of air/vacuum/suction, and I would the "feedback" in the throttle, then it would cease to run... but would fire right back up.
so I took the air cleaner off, and did it some more... then there were puffs shooting up from the carb, then I saw flame shoot out. So I stopped.
what now?
If I revved it, it would rev up, but at random times, I would hear alot of air/vacuum/suction, and I would the "feedback" in the throttle, then it would cease to run... but would fire right back up.
so I took the air cleaner off, and did it some more... then there were puffs shooting up from the carb, then I saw flame shoot out. So I stopped.
what now?
Race Director
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
i think you need to square away the fuel supply...pressure and volume do cross lines when you have sufficiently blocked flow so i am not sure you can draw any conclusions from badly crimped lines on what you actually are getting unless you measure it.
if you continue to use the fuel pump you have then get an adjustable fuel regulator on the system, holley makes a nice one for about $25 and get a PSI guage for the the other port on the regualtor. this will at least let you klnopw for sure the pressure you are running...other options would be to buy a square electronic fuel pump and use that with a gas can and see if you get the car running well. if so you know its a fuel supply issue
if you continue to use the fuel pump you have then get an adjustable fuel regulator on the system, holley makes a nice one for about $25 and get a PSI guage for the the other port on the regualtor. this will at least let you klnopw for sure the pressure you are running...other options would be to buy a square electronic fuel pump and use that with a gas can and see if you get the car running well. if so you know its a fuel supply issue
Last edited by bobs77vet; Jun 25, 2011 at 06:40 PM.
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Since it's not a C3 may not be totally familiar with your set up but did you check the timing? Did you check if the advance mechanism in the distributor is freely moving. By the way Quadrajets typically use 3/8" fuel lines for feed, 1/4" is too small.
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I just got done with the new fuel line, and a new in-line filter
it's still doing the same thing though. I fired it up, it would die if I left it to idle, but if I revved it would run for a while, then sounded like it was sucking air, and would try to die... if I floored it hard, it would catch again, then would backfire (flame out the cab)
it's still doing the same thing though. I fired it up, it would die if I left it to idle, but if I revved it would run for a while, then sounded like it was sucking air, and would try to die... if I floored it hard, it would catch again, then would backfire (flame out the cab)
Last edited by MonteHall; Jun 26, 2011 at 07:16 PM.
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
I just got done with the new fuel line, and a new in-line filter
it's still doing the same thing though. I fired it up, it would die if I left it to idle, but if I revved it would run for a while, then sounded like it was sucking air, and would try to die... if I floored it hard, it would catch again, then would backfire (flame out the cab)
it's still doing the same thing though. I fired it up, it would die if I left it to idle, but if I revved it would run for a while, then sounded like it was sucking air, and would try to die... if I floored it hard, it would catch again, then would backfire (flame out the cab)
