Cuts metal like mad Posted February 27, 2009 Report Share Posted February 27, 2009 Ok, so I finally took the 510 on a long freeway cruise, she did ok at 60... but these days not many people are doing 60, so I step it up to about 75. After cruising for about 10 minutes (stock 4speed), the R1 carbs run out of fuel all together, I let off the gas and coast the to the right lane, after only a few seconds off the throttle and out of gear, I stuff it back into fourth and she refires... relief, since I had a half tank of gas and now I know what the problem is, and this also proves my theory that the stock mechanical pump is just not providing the volume needed to keep the carbs full. So I pull off the freeway and cruise city streets the rest of the way home with no issue... Anyone running a high volume low pressure pump? Need no more than about 3.5psi... I know I'll need a fuel pressure regulator... Quote Link to comment
Guest DatsuNoob Posted February 27, 2009 Report Share Posted February 27, 2009 I have a stock high pressure inline fuel pump from a turbo eclipse that works. I'll make you a helluva deal :D Quote Link to comment
banzai510(hainz) Posted February 27, 2009 Report Share Posted February 27, 2009 Joe You really think its the fuel pump.??????Ever take the out put off and point it in a safe directio? Man thats alot of gas shooting out. I runa stock pump on my beater with 40mm Mikunis Quote Link to comment
datzenmike Posted February 27, 2009 Report Share Posted February 27, 2009 (edited) The capacity test is to run a hose into a suitable container start motor and hold at 1,000 RPMs for 1 minute. It should deliver 1 liter... that's close to a US quart. That... is a lot of fuel. 10 gallon tank empty in 45 minutes. Edited February 27, 2009 by datzenmike Quote Link to comment
hang_510 Posted February 27, 2009 Report Share Posted February 27, 2009 i have some random brand in the wagon that i plan on reusing. i have a carter on the sedan w/a regulator. never had issues w/ either. have you checked the lines/filter for clogs??? Quote Link to comment
Cuts metal like mad Posted February 28, 2009 Author Report Share Posted February 28, 2009 Its definately the pump, it runs great at city speeds, no problems... at prolonged higher rpm cruising it runs out of fuel. If I had a set of webers it wouldn't be a problem... they have big fuel bowls, but because the fuel bowls are rather small on the R1 carbs, it is necessary to run something that puts out a higher volume... it was documented in the R1 carb article I posted, but I chose to try it with the stock pump anyway, if I didn't mind driving at lower speeds, or swapped in a 5spd... well the issue would go away, but those are not options. Justin, that pump would be too much pressure for carbs, need LOW pressure/high VOLUME. I have some ideas but was hoping for a bit better response than this... Quote Link to comment
ggzilla Posted February 28, 2009 Report Share Posted February 28, 2009 Use the Nissan electric fuel pump. I have it works great. Don't know what it came out of though. Btw, a partially plugged fuel filter can cause the symptoms you are experiencing. I would do the pump volume test (as described earlier). Quote Link to comment
phatdave Posted February 28, 2009 Report Share Posted February 28, 2009 (edited) Ive got a $80.00 Carter that is recommended by Redline Weber carbs...slightly used ..excellent shape. 25.00$ dave Edited February 28, 2009 by phatdave typo Quote Link to comment
datzenmike Posted February 28, 2009 Report Share Posted February 28, 2009 '79 620 with air has electric. All 720 had electric inline pump mounted just forward of the pass side rear wheel on the outside of the frame. They are capable of 3,5 lbs. I think most others cars after '80, except the HLA10, are high EFI pressure pumps Quote Link to comment
phatdave Posted February 28, 2009 Report Share Posted February 28, 2009 like this........http://www.federal-mogul.com/en/AftermarketSolutions/NorthAmerica/EngineSolutions/Products/CarterFuelDelivery/CarterElectricFuelPumps/RotaryVane/ Quote Link to comment
jesusno2 Posted February 28, 2009 Report Share Posted February 28, 2009 Back in the 90's my 620 I had with bike carbs, I ended up running a holley high volume pump(I think it was the blue one) as I had the exact same issue. I tried factory electric pumps but I still drained the fuel bowls. I also belive I put bigger fuel lines on the truck to hold more volume. I ran super low pressure too like around 1 pound to keep from overpowering the float needles. Quote Link to comment
Cuts metal like mad Posted February 28, 2009 Author Report Share Posted February 28, 2009 great info thanks guys. The stock R1 electric fuel pump runs 3-3.5psi... so I should be fine in that range. If I can find one of them for cheap I'll go that route, if not I'll go with something else... but I'll keep you posted dave, thank you. Quote Link to comment
banzai510(hainz) Posted February 28, 2009 Report Share Posted February 28, 2009 forgot about the small float bowls!!!!!!!! Quote Link to comment
ggzilla Posted March 1, 2009 Report Share Posted March 1, 2009 Here is the factory Nissan pump. 3.5 - 4.0 lbs -- perfect for Hitachi or Weber carburetor Same one I have in my Datsun pickup: rockauto.com Quote Link to comment
Guest DatsuNoob Posted March 1, 2009 Report Share Posted March 1, 2009 I was just screwin around, I know, waaaaay too much pressure. I just thought if you could make it work with a fpr, it would be free. Quote Link to comment
Jason Posted March 1, 2009 Report Share Posted March 1, 2009 Joe, you probably have a L20b fuel pump around. Those have a higher volume, same 3.5lb low pressure as the L16 pump. Why don't you try that and see if it'll give you enough fuel? It'd be cheap to try anyhow! Quote Link to comment
Cuts metal like mad Posted March 1, 2009 Author Report Share Posted March 1, 2009 More good info, thanks guys! You guys really know me.... *cheap ass* :lol: (or brokeass) Quote Link to comment
Cuts metal like mad Posted March 2, 2009 Author Report Share Posted March 2, 2009 UPDATE! Go here; http://forum.ratsun.net/showthread.php?t=8017&page=4 Quote Link to comment
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