710 not getting fuel

[gmkeegan]

hi guys so i'm trying to start my 710 and she is not getting fuel.. the filter has gas in it. the pump is pumping but yet no fuel is going into the carb. i pulled off the line and blown into the carb no problem... also i have a little gravity tank i hooked up it runs right in. but then when i hook it back up nothing empty bowl... now i dont have the cap on the gas tank i dont think that has anything to do with my fuel issue but i dont know any ideas??? thnaks

 

 

 

this is a water bottle that i connected so i can see if the fuel pump is working.. this is also 10 seconds of me holding the key should there me more fuel in it ?  

 

 

 

[Lockleaf]

Have you tried manually filling the bowl? I had to do that on my 620 before it would pull fuel through the carb.

[bilzbobaggins]

Needle sticking? Rap on the banjo bolt fitting with a screw driver handle. See if that works.

 

Or pour a little down the throat and start it. The fast idle should fill it up

[Draker]

Do stock carbs have last chance filters? 

[banzai510(hainz)]

if fuel pump outlet is pumping fuel. then as Blizbogannin say tap the banjo fitting where the gas line goes into the carb and tap while craking. this might loosen the sticky needle valve as that LOOKS 95% the proplem.

 

 

that gas looks old. Put another filter on there before you suck up dirt and plugged that carb Yes the idle jet

[gmkeegan]

Have you tried manually filling the bowl? I had to do that on my 620 before it would pull fuel through the carb.

i have filled it... all it does run then shut off once the gas runs out.

 

Needle sticking? Rap on the banjo bolt fitting with a screw driver handle. See if that works.

 

Or pour a little down the throat and start it. The fast idle should fill it up

i'm going to try this.. but why would it allow gas in when i have my little gravity tank?

[LenRobertson]

Inside the banjo fitting on top of the float chamber (fitting that your rubber gas line hooks to) may be a fine mesh screen filter. Sometimes these get discarded, but if you have one it could be plugged up. Spray it with carb cleaner and blow it off. While the banjo fitting is off you can spray more carb cleaner down onto the needle and seat and maybe free it up if it is sticky.

 

Len

[bilzbobaggins]

If it's coming out the output of the pump and can't get to the carb, dunno. Bad fuel line between carb and pump?

[banzai510(hainz)]

OK make this simple

If out of fuel pump puts gas to the carb then it should be no different than the gravity feed. the fuel pump should be pushing the gas to the carb.

 

unless tha fuel pump has alot of pressure(Im fucking guessing on this one). I assume stock fuel pump

 

 

Its like the valve in you TOILETBOWL exactly the same

[gmkeegan]

OK make this simple

If out of fuel pump puts gas to the carb then it should be no different than the gravity feed. the fuel pump should be pushing the gas to the carb.

 

unless tha fuel pump has alot of pressure(Im fucking guessing on this one). I assume stock fuel pump

 

 

Its like the valve in you TOILETBOWL exactly the same

 

If it's coming out the output of the pump and can't get to the carb, dunno. Bad fuel line between carb and pump?

 

Inside the banjo fitting on top of the float chamber (fitting that your rubber gas line hooks to) may be a fine mesh screen filter. Sometimes these get discarded, but if you have one it could be plugged up. Spray it with carb cleaner and blow it off. While the banjo fitting is off you can spray more carb cleaner down onto the needle and seat and maybe free it up if it is sticky.

 

Len

 

Do stock carbs have last chance filters? 

soi kind of figured it out... i turns out its not the fuel pump it's not the carb its my feed line from my gas tank or the tank itself.. i ended up taking a bottle and filling it with gas and running it right before the pump and as soon as i did that it ran right into the bowl and started right up!!  now i know it show gas in my filter right before the pump but for some reason its not allowing it to pump through. its holding the gas back. i have a feeling there is something caught in the line or something in the tank.. will update more tomorrow.

[gmkeegan]

OK make this simple

If out of fuel pump puts gas to the carb then it should be no different than the gravity feed. the fuel pump should be pushing the gas to the carb.

 

unless tha fuel pump has alot of pressure(Im fucking guessing on this one). I assume stock fuel pump

 

 

Its like the valve in you TOILETBOWL exactly the same

 

If it's coming out the output of the pump and can't get to the carb, dunno. Bad fuel line between carb and pump?

 

Inside the banjo fitting on top of the float chamber (fitting that your rubber gas line hooks to) may be a fine mesh screen filter. Sometimes these get discarded, but if you have one it could be plugged up. Spray it with carb cleaner and blow it off. While the banjo fitting is off you can spray more carb cleaner down onto the needle and seat and maybe free it up if it is sticky.

 

Len

 

Do stock carbs have last chance filters? 

 

Have you tried manually filling the bowl? I had to do that on my 620 before it would pull fuel through the carb.

thanks again for all your help

[LenRobertson]

soi kind of figured it out... i turns out its not the fuel pump it's not the carb its my feed line from my gas tank or the tank itself.. i ended up taking a bottle and filling it with gas and running it right before the pump and as soon as i did that it ran right into the bowl and started right up!!  now i know it show gas in my filter right before the pump but for some reason its not allowing it to pump through. its holding the gas back. i have a feeling there is something caught in the line or something in the tank.. will update more tomorrow.

Good news that you've narrowed down the problem. It would be best to take  loose the rubber line between the tank and the hard line that goes to the fuel pump before you blow through it. That way if there is something in the line it won't get blown back into the tank. When I got my 510 it had been sitting out in the sun for years. The hard line back to the tank was sludged up with dried gas and wouldn't feed fresh gas from the tank. I had to spray carb cleaner in the hard line from both ends, then blow out with compressed air. I repeated this 3 or 4 times to dissolve all the sludge.

 

I don't know if a 710 has a drain plug on the bottom of the tank like older Datsuns do. If it does you can try draining the tank and if there is something in the tank that gets sucked over the outlet line, it might flush out the drain hole (but no guarantee it will). You may need to remove the tank and clean it, but of course that is the last resort.

 

Len

[gmkeegan]

Good news that you've narrowed down the problem. It would be best to take  loose the rubber line between the tank and the hard line that goes to the fuel pump before you blow through it. That way if there is something in the line it won't get blown back into the tank. When I got my 510 it had been sitting out in the sun for years. The hard line back to the tank was sludged up with dried gas and wouldn't feed fresh gas from the tank. I had to spray carb cleaner in the hard line from both ends, then blow out with compressed air. I repeated this 3 or 4 times to dissolve all the sludge.

 

I don't know if a 710 has a drain plug on the bottom of the tank like older Datsuns do. If it does you can try draining the tank and if there is something in the tank that gets sucked over the outlet line, it might flush out the drain hole (but no guarantee it will). You may need to remove the tank and clean it, but of course that is the last resort.

 

Len

thanks len! 

 

yeah after finding the problem was the hard line i did what you said prior to you saying it lol wasn't going to post picture but since you talked about it i thought i should.  the great thing about the 710 is the gas tank is in the trunk and easy to remove minus the two bolts between the back seat and the tank other then that easy.

 

 

the one is feed the other is return 

 

 

the big one is the feed and the little one is the return 

 

this is a progress picture of the line the far right being the first bottle 

 

this is a picture of the first bottle being turned upside down. i did this to show how much tar and crap was in the bottle. this is only from the feed line i still can't get the return line cleared going to try it again tomorrow. 120 PSI and it still wont blow through.  :confused:

[datzenmike]

My 710 sedan was that bad. Drove it 15 miles after buying it till it quit. Pulled the filter off and shook the crap out got another 20 miles did it again and was good for the last 60 miles. Replaced the filter at home and it was plugged in two weeks. Tank had to come out. Drained it (got a cup of what looks like varnish flakes out of the tank with the gas) and removed the fuel gauge sender as it's the only good opening and too sensitive for what was next....  Three double hand fulls of clean driveway gravel and shake and roll the tank around to dislodge all the crap. Don't be shy, give it a good shaking. Dump out and hose it out.... repeat. Left for the afternoon in the sun to dry and put back together with a new filter.... good ever since.    

[banzai510(hainz)]

WOW!!!!!!!!!!!!

[LenRobertson]

Yeah, that looks like what I got out of my 510 hard line. I used marbles and acetone to clean my tank, but I'm not sure that was aggressive enough since the gas in the fuel filter continues to have a brownish tinge. Gravel sounds like a better idea, but I'm not having problems to I'll leave it alone.

 

Yesterday I started working on the fuel supply problems on my F10. If I'm ever going to sell it it really needs to be running more or less well. I got the carb base nuts tightened down (helped by sawing off a 10mm wrench as recommended by datzenmike when he stopped by). I started taking the rubber hoses off the hard line although I know I've done it before. But it is easy to blow through the supply hard line just to be certain it is clear. I don't think I've drained the tank yet to look for junk in it, but it has a drain plug. But just when I really got involved working on it a big rain shower hit. Ultimately the tank may need to come off and get the gravel treatment. I'd rather be working on the 510, but the F10 isn't going to heal itself.

 

Len

[gmkeegan]

My 710 sedan was that bad. Drove it 15 miles after buying it till it quit. Pulled the filter off and shook the crap out got another 20 miles did it again and was good for the last 60 miles. Replaced the filter at home and it was plugged in two weeks. Tank had to come out. Drained it (got a cup of what looks like varnish flakes out of the tank with the gas) and removed the fuel gauge sender as it's the only good opening and too sensitive for what was next....  Three double hand fulls of clean driveway gravel and shake and roll the tank around to dislodge all the crap. Don't be shy, give it a good shaking. Dump out and hose it out.... repeat. Left for the afternoon in the sun to dry and put back together with a new filter.... good ever since.    

 

Yeah, that looks like what I got out of my 510 hard line. I used marbles and acetone to clean my tank, but I'm not sure that was aggressive enough since the gas in the fuel filter continues to have a brownish tinge. Gravel sounds like a better idea, but I'm not having problems to I'll leave it alone.

 

Yesterday I started working on the fuel supply problems on my F10. If I'm ever going to sell it it really needs to be running more or less well. I got the carb base nuts tightened down (helped by sawing off a 10mm wrench as recommended by datzenmike when he stopped by). I started taking the rubber hoses off the hard line although I know I've done it before. But it is easy to blow through the supply hard line just to be certain it is clear. I don't think I've drained the tank yet to look for junk in it, but it has a drain plug. But just when I really got involved working on it a big rain shower hit. Ultimately the tank may need to come off and get the gravel treatment. I'd rather be working on the 510, but the F10 isn't going to heal itself.

 

Len

yeah i got my tank clean it's just the return line now. the tank had some flakes in t but its 100% clean now i'm still thinking of running an inline filter before the hard line. Has anyone done this? Len or mike any ideas on how to clear the hard return line? i tried gas and 120psi got no where the problem is the return line is smaller it kind of sucks. any ideas will help? going to try a wire sticking it up it or brake fluid idk 

[LenRobertson]

yeah i got my tank clean it's just the return line now. the tank had some flakes in t but its 100% clean now i'm still thinking of running an inline filter before the hard line. Has anyone done this? Len or mike any ideas on how to clear the hard return line? i tried gas and 120psi got no where the problem is the return line is smaller it kind of sucks. any ideas will help? going to try a wire sticking it up it or brake fluid idk 

I don't have a return line on my 510 so didn't have to deal with it. To clean my supply line I sprayed carb cleaner into the line from both ends and let it sit for awhile, then hit it with compressed air. Repeated this several times until the carb cleaner being blown out was fairly clear. It is possible my line wasn't completely blocked though which would make it easier for carb cleaner to move through it. If your return line is blocked solid it make take time to dissolve the sludge.

 

Are the ends of your return line oriented so you can run 3 or 4 feet of fuel line outside the car or up in the engine compartment and use a small funnel to pour in acetone or lacquer thinner or carb cleaner? The rubber hose would keep the solvent from running back out of the hard line. I don't know if that would work; just a thought.

 

There is a point where running a new return line may be less effort than cleaning the old one.

 

Len

[banzai510(hainz)]

I run the stock Nissan type filter then run a inline one also before the fuel pump. Once you think its clean after awhile I go back to the stock one

On my 521 I run 2 as 521 tanks seem dirtier as the fuelline is in the wheelwell and dirt tracks down it.

[gmkeegan]

I run the stock Nissan type filter then run a inline one also before the fuel pump. Once you think its clean after awhile I go back to the stock one

On my 521 I run 2 as 521 tanks seem dirtier as the fuelline is in the wheelwell and dirt tracks down it.

so i got it cleared!!! so happy!! i ended up using a wire and shoved it into the hole. made my day tomorrow i get some new fuel line and see what happens 

[datzenmike]

I used a very flexible speedometer cable once. It wasn't blocked, I just thought it might be. Went in about 5 feet from each end.

[gmkeegan]

I used a very flexible speedometer cable once. It wasn't blocked, I just thought it might be. Went in about 5 feet from each end.

i finally got it!! i used a small screwdriver and a wires and got it all clared!! then cleared the tank put it all back together a bam!! fired right up runs good can't complain!!