jon521 Posted December 1, 2011 Report Share Posted December 1, 2011 Fixed my flooding problem. I thought the return line from the carb had clogged up- truck had run fine for 18 months with the Weber with no flooding and ~30MPG, but around mid-August the mileage dropped into the mid-20s and I had fuel dripping out of the air cleaner. Float was still floating, but the fuel pump was forcing fuel in. Around September I tried putting air to the return line to blow it out- NOTHING. 120PSI and all I did was make balloons out of the fuel return hose up front. Since the tank is not original (it's a 15+ gal aftermarket tank) the fuel lines are inaccessible. Tried a fuel pressure regulator, which erupted in Chelan in early October. Got a new regulator which made the engine starve for fuel on anything but "wide open" at which point it just started flooding again. Irregardless of the weather, used this weekend to try and figure out where the clog was. Detached the hard lines and the connector block on the frame. ALL clear of clogs, but full of muddy brown fuel. Still clogged from that point back though. Since I could kind of reach the tank connections through the rear wheelwell I decided to try and trace the lines. The supply line I deduced to be the larger line- it was. The vent lines had a "T" that went from the fuel tank to the vapor tank, up to the fill hose as well as up to the carbon canister. Popped that hose off and sent air down the hose from the carbon canister- yes, that line was both clear and correct. None of these are the fuel return line though. There was one capped-off line coming up from the frame, I thought came from the bottom of the tank but no lines were there. The "cap" was a piece of 1/4" fuel line with a body screw held in with a hose clamp. NOT original. So on a whim I uncapped the line and ran air down the return line... yup, that's it. The bugger was capped off the whole time. Whoever installed the aftermarket tank never hooked up the return line. There even was an extra corresponding capped line on the tank (that one was a factory dust cap though) . There's only maybe 2 1/2 - 3" of clearance from the bed to the tank top, but I was able to snake a fuel hose on there and clamp it on. Ditched the regulator, and the truck runs perfect again. No more flooding, no more erratic idle. It's still a wonder why it worked for so long without flooding though. Must have weakened the float/float valve. return fuel line with a weber?............. Quote Link to comment
izzo Posted December 1, 2011 Report Share Posted December 1, 2011 return fuel line with a weber?............. Yup I've never had to use one, but my orange 510 had it, with a second fuel filter on it. Its a good idea to have one, really. There isn't one on my truck now, but i can smell gas every time i get out. And its running an electronic fuel pump. So ill be getting to it asap. Quote Link to comment
jon521 Posted December 2, 2011 Report Share Posted December 2, 2011 Yup I've never had to use one, but my orange 510 had it, with a second fuel filter on it. Its a good idea to have one, really. There isn't one on my truck now, but i can smell gas every time i get out. And its running an electronic fuel pump. So ill be getting to it asap. id be interested in how you would run it, as i also have a electric fuel pump and 32/36 Quote Link to comment
wayno Posted December 2, 2011 Report Share Posted December 2, 2011 I got quite a bit done today, I started by connecting the heater control lever, the defrost/room one, that's nice, I can quit using the squeege now:lol:, I then went to curlys lock and key and had them key the two door locks, went home and installed the door locks after pulling every door lock I had looking for mounting parts, keepers and such, and then I put sound deadener inside the doors, and made temporary door panels out of that plastic political sign material, but it is not any quieter:(. I put the front turn signal covers back on inside the fender wells so mud won't get in there. After I got done with that, I went in the back and spun the two 411 geared 720 third members, to see which one was the tightest, so I could make one up for ole' 320s L320 truck, it turned out that neither of them were 411s, one was 390 gears, and the other was 440/450 something, Grrrrr, they were both supposed to be 411s, so off to the wrecking yards to find a 411 pumpkin, which I found at the vancouver pick&pull for $125.00, Grrrrrr, that was to much, but didn't have a choice anymore, it was tight, so I bought it. On the way home I used the impact to take the steering wheel nut off to ajust the steering wheel so it was centered rather than being pointed at 1:30pm. I stopped at the auto parts store and bought some oil filters and fuel filters and some spray degreaser for the tach senser, I am going to change everything before the trip to LA saterday, I put a new set of tires on last week. After all that I took a shower, went and filled the truck up with diesel, and went to the store and spent another $50.00+ on food, it was an expensive day. Quote Link to comment
ggzilla Posted December 2, 2011 Report Share Posted December 2, 2011 Fuel return line in many Datsuns does not actually connect to the carburetor. It Tees into the main fuel line just before the line connects to the carburetor. The purpose is to keep the fuel flowing in a loop to avoid hotspots (thus no fuel lock) and to keep fuel cooler overall (thus less evaporative emissions). Quote Link to comment
ronnny Posted December 2, 2011 Report Share Posted December 2, 2011 Fuel return line in many Datsuns does not actually connect to the carburetor. It Tees into the main fuel line just before the line connects to the carburetor. The purpose is to keep the fuel flowing in a loop to avoid hotspots (thus no fuel lock) and to keep fuel cooler overall (thus less evaporative emissions). On my 84 4x4, that i bought not running and cheap, I had fuel problems when i started it. It would run at idle but soo as you tried to go down the road would die. I found that what ever restricts most of the fuel from going back the return was gone and i had next to no preasure. I capped off the return and have had no problem since. I am also running a old 32/something weber. One day i will look to see how the fuel line return was supose to be restricted. The one i bought the truck from said the one he got the truck from on a trade had rebuilt the motor. But to leave this part out you would wonder how well of a job he would do on a rebuild. All i know is i got a good 2.4 that leaks no oil or water for less than 500 in it. Quote Link to comment
wayno Posted December 3, 2011 Report Share Posted December 3, 2011 I accomplished quite a bit today on my 521 kingcab diesel, I changed the oil and filter, tightened the alt. belt again???, then I moved to the interior, I put a complete 720 console in it, I decided I wanted a radio, so I put this pioneer I had in the console, not the dash, as I didn't want to cut the radio hole, as it is uncut with a radio delete plate, then I found some box speakers, connected everything up and it turned right on, but when I shut off the truck, I lost the radio station, I swapped the two wires I had backwards, and it is fine now. I then connected up the 720 volt meter, I ajusted the tach senser, now it works perfect to. The truck is now loaded up for the trip to LA, the one issue I see is that my rear leafs have about 2 to 3 inches of space between them and the frame. I hope it doesn't bottom out a lot, as the bump stops are gone, looks like a frame notch in the future. I also setup ole'320s 3rd member, it now has 320 side gears in a 411 gearset for his 65 datsun 320. Quote Link to comment
Dirttrack510 Posted December 9, 2011 Report Share Posted December 9, 2011 I didn't really do anything to my truck today, but i did arrange to have it shipped home from Rosamond, CA to St. Louis, MO today. Quote Link to comment
jon521 Posted December 9, 2011 Report Share Posted December 9, 2011 I didn't really do anything to my truck today, but i did arrange to have it shipped home from Rosamond, CA to St. Louis, MO today. well you gotta have it around to work on it, so thats a step forward! Quote Link to comment
Farmer Joe Posted December 9, 2011 Report Share Posted December 9, 2011 well the day before yesterday... but who cares.. adjusted the lash on the valves... all outta whack again.. removed all the choke bulshit from the motorcraft.. wasnt hooked up, nor did it work.. douched the carb out, and cleaned the idle primary jet.. it had a low speed issue.. re-gapped the plugs. good ol ngk's kick ass! runs good now... still a cold blooded as a mofo tho... i need a rebuild soon... or another motor.. Quote Link to comment
Dirttrack510 Posted December 9, 2011 Report Share Posted December 9, 2011 well you gotta have it around to work on it, so thats a step forward! Yep, I can't hardly wait for it to get here, I got it for free from my grandfather. HE WAS GONNA SEND IT TO THE SCRAPPER!!! :sick: :no: :sick: It's costing me a grand in title fees and shipping charges :crying: to get my "free" truck home, but at least it's one more saved and going back on the road. I can hardly wait to get going on it over the winter. :D :D :D Quote Link to comment
510Chad Posted December 9, 2011 Report Share Posted December 9, 2011 STILL trying to finish the SU conversion. Almost there. Need to put coolant back in the system and hook up some fuel delivery and the exhaust to the header. Oh and figure out a way to choke the carbs without buying a $50 cable... Quote Link to comment
Dirttrack510 Posted December 9, 2011 Report Share Posted December 9, 2011 Autojoke sells a choke cable kit for like $15 Quote Link to comment
510Chad Posted December 10, 2011 Report Share Posted December 10, 2011 Autojoke sells a choke cable kit for like $15 Dual pull? Or is it the standard single with a round knob and silver corrugated sleeving? Quote Link to comment
crackerjack69 Posted December 10, 2011 Report Share Posted December 10, 2011 Bought these tonight for the 620 :hyper: Quote Link to comment
jon521 Posted December 10, 2011 Report Share Posted December 10, 2011 i bought some stock wheels, full set for 50 bones Quote Link to comment
gene knight Posted December 10, 2011 Report Share Posted December 10, 2011 did not do a damn thing to my datto yesterday, but i am planning on working on it today Quote Link to comment
elmerfudpucker Posted December 10, 2011 Report Share Posted December 10, 2011 walked by my truck and wondered when I could drive it again... :( Quote Link to comment
nismo dr Posted December 11, 2011 Report Share Posted December 11, 2011 Starter went out this morning. Got a Bosch unit, Discount Import Parts had it in stock. Quote Link to comment
lil89ram50 Posted December 12, 2011 Report Share Posted December 12, 2011 dove the 521 out of the heated garage, pulled in chevy, adjusted valves and drove datsun back in... i miss driving this so bad Quote Link to comment
socaldatsun Posted December 13, 2011 Report Share Posted December 13, 2011 Drove to autozone "since all i hear that you cant drive your trucks:D" and bought A new windsheild whiper. didnt have enough for the pasanger side lol 1 Quote Link to comment
510Chad Posted December 14, 2011 Report Share Posted December 14, 2011 Finished the SU conversion (minus a choke solution) and drove it to work this morning.... Quote Link to comment
KC Phirus Posted December 15, 2011 Report Share Posted December 15, 2011 Backed the hood pin thingy out so I pops when you pull the lever. (before, I had to open the door and pull the lever and lift the hood at the same time XD) Pulled the bumper and valance off so I can repair the dents in them and paint behind them. Only broke 3 bolts in the valance! Just gotta get three good bolts out of the parts truck. Quote Link to comment
KC Phirus Posted December 15, 2011 Report Share Posted December 15, 2011 Started her up for a stroll around the yard, cloud of smoke over my neighborhood. Cleared up after a couple minutes and ran great. Valve guide seals? Quote Link to comment
gene knight Posted December 18, 2011 Report Share Posted December 18, 2011 installed new fuel pump, did some wiring testing to insure that i won't need to use a jumper wire from + side of battery to coil. Quote Link to comment
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