djmoreron Posted September 15, 2007 Report Share Posted September 15, 2007 turned out to be a bit of a pain. ive never done one before, but it looked pretty stragithtforward. only problem is that on my truck the air conditioning is blocking the pump, and needs to be removed first. ive never done this before either. how do i loosen the belts? anything else i should know before i dive in? Quote Link to comment
datsunaholic Posted September 16, 2007 Report Share Posted September 16, 2007 The air conditioning is blocking the pump? Uh, Air Conditioned trucks don't HAVE a mechanical pump. Well, 1974 and earlier ones did but the A/C compressor was on the other side of the engine, basically on top of the steering box. On '75 and later with factory air the A/C pump takes over the entire area where the fuel pump would be, so those trucks came with an electric pump mounted on the frame next to the gas tank. If the A/C is non-factory then it's just strange and non-standard. Quote Link to comment
ppeters914 Posted September 16, 2007 Report Share Posted September 16, 2007 Maybe a pic or two would help? Quote Link to comment
djmoreron Posted September 16, 2007 Author Report Share Posted September 16, 2007 maybe its not the ac thats blocking it, but something certainly is. as soon as my camera battery charges ill post pics Quote Link to comment
djmoreron Posted September 16, 2007 Author Report Share Posted September 16, 2007 see that big grey thing with a belt to the right of the battery? what is that? isnt the piece on top with the rusty screws my fuel pump? it has a fuel hose connected to it straight from my fuel filter... Quote Link to comment
kiznook Posted September 16, 2007 Report Share Posted September 16, 2007 yes that's the fuel pump, And YES that is the AC compressor. I don't know how the belt tension is adjusted on that setup, but you probably just need to loosen the topand bottom bolts tha hold the compressor on and it should slide to adjust, might be able to swing far enough to get that fuel pump off. Why are you going after it in the first place? Doesn't look like you've replaced the filter yet ;) Quote Link to comment
tnip Posted September 16, 2007 Report Share Posted September 16, 2007 where's the alternator at on 620's? been a while since i've looked at one. Quote Link to comment
mklotz70 Posted September 16, 2007 Report Share Posted September 16, 2007 Considering the hose clamps on everything and the bracket itself....I'd lay money that it is not a factory setup. At least in the '78 factory manual(online at http://www.the620.com) it has a piston style pump on that side of the engine, but, as 'aholic said....it had an electric pump. The pivot points on your bracket are on the top, so look around the bottom side for the slots. You have two pivot bolts on top....loosen those and you may have two on the bottom(front/rear). You going to have some spring pressure from the pump arm....can you push against that to angle the pump enough to get it off? Quote Link to comment
dat521gatherer Posted September 16, 2007 Report Share Posted September 16, 2007 only other way is to use two nuts and butt them up to remove the fuel pump studs. only problem is you run the risk of striping the studs if it doesn't work. Quote Link to comment
datzenmike Posted September 16, 2007 Report Share Posted September 16, 2007 That poor alternator. Sharing with other roomies. Quote Link to comment
kiznook Posted September 16, 2007 Report Share Posted September 16, 2007 judging by the hose clamps, my guess would be that the AC system doesn't work, or at least not very well. I would say ditch the AC and sell it to someone looking for a comfort ride :D OH WAIT you're in california....that changes things Quote Link to comment
OL YELLER Posted September 16, 2007 Report Share Posted September 16, 2007 UM would someone please explain to me, where is the altenator on this engine????...even my '72 with the dealer installed "factory air?" had the compressor on the drivers side above the steering box...hey what gives here? Doug? you ever seen one like this un? Quote Link to comment
djmoreron Posted September 16, 2007 Author Report Share Posted September 16, 2007 i replaced the fuel filter 2 weeks ago, didnt change my stalling issue. the alternator is below the ac thing, you cant see it to well from above, even in person. i wish i had enough room to angle the pump to get it off, but i have less than 1/4 inch of play to move it. im gonna try to pivot it like you guys said. i did loosen two bolts that i thought would make it pivot, but it didnt budge. and the ac system does work, not the best, but it works! Quote Link to comment
datsunaholic Posted September 16, 2007 Report Share Posted September 16, 2007 Ron, the factory A/C starting in '75 was on the passenger side, above the alternator. Couldn't put it on the driver's side with the air pump in the way like the cars, because the steering box left room for only one unit over there. The factory 620 A/C bolted the bracket where the fuel pump was, using the fuel pump flange studs and the hole for the ground strap on the head. Hence, the fuel pump had to go. This mess pictured above is some home-brew backyard attempt at making an A/C system. The Reciever/Drier should NEVER be mounted sideways- should ALWAYS be vertical, with teh sight glass up. All A/C before '75 was dealer add-on, and having no air pump meant the compressor fit over on the driver's side. Quote Link to comment
kiznook Posted September 17, 2007 Report Share Posted September 17, 2007 I'm thinkin we should evaluate whether the fuel pump is the problem or not. What symptoms does it have? Quote Link to comment
datzenmike Posted September 17, 2007 Report Share Posted September 17, 2007 Good idea. Stalling when cold or warm could be any number of things from incorrect fast idle setting to a stuck or dirty EGR valve. Quote Link to comment
dat521gatherer Posted September 17, 2007 Report Share Posted September 17, 2007 what is exactly the problem to where you want to replace the fuel pump? if in doubt try bolting it back up and removing the hose that goes to the carb and see if fuel squirts out when you turn the engine over. Quote Link to comment
djmoreron Posted September 17, 2007 Author Report Share Posted September 17, 2007 well, when cold or warm, the truck will start for a few seconds then die (this happens every time i try to start it). after a few more tries i can usually get it going. sometimes while driving the motor will randomly cut like its not getting fuel, its still on (and idling rough), but when i press the gas nothing happens. i can pull over and turn it off, then it fires right up. just yesterday, i started the truck, drove about two feet and it shut off like i let go of the clutch (i didnt). tried to start it again and no go. ive changed the plugs, wires, distrbutor cap and rotor, and fuel filter so far but nothing has made a difference ...didnt think to check the egr valve. whats a fast idle setting? thanks Quote Link to comment
kiznook Posted September 17, 2007 Report Share Posted September 17, 2007 sounds like carb to me. Fuel pump (in this case) is usually work/no work. not random. seriously its mechanical, if it runs at all, especially driving down the road, not likely its the pump. Quote Link to comment
tnip Posted September 17, 2007 Report Share Posted September 17, 2007 the next thing i'd check is the carb, like kiznook said. maybe a quick rebuild and tune? Quote Link to comment
ppeters914 Posted September 17, 2007 Report Share Posted September 17, 2007 Or there's crap in the tank that's randomly blocking the outlet tube until you hit a bump or change uphill/downhill. Quote Link to comment
djmoreron Posted September 18, 2007 Author Report Share Posted September 18, 2007 should i go weber or rebuild the hitachi. i found a place that sells weber carbs near my job. they seem to have 3 different types that would fit. any difference between them, besides price? 32/36 DGEV - $355 38 DGES - $380 32/336 DGV - $320 http://www.racetep.com/weber/nistruckskit.html Quote Link to comment
datsunaholic Posted September 18, 2007 Report Share Posted September 18, 2007 Go with the weber, unless you need to have it smog checked. The DGV won't be smog legal (manual choke) nor will the 38DGES (not CARB approved). The 32/36 DGEV MIGHT be smog legal, but only if you can retain the stock air cleaner. Quote Link to comment
mklotz70 Posted September 18, 2007 Report Share Posted September 18, 2007 I'm with Pete on the fuel tank junk. Seriously....how does it run when it runs? If it runs great when it runs, then I wouldn NOT spend the money to switch to a weber. Put a clear filter before the pump and another after the pump. You can run fuel hose instead of the hardline until you get this figured out. If there's fuel in the first and not the second, it's the pump.....but as Kiznook said....it's really unlikely that the fuel pump would be intermittent. More likely you have crap in the tank, as Pete said.....or you have crap in the carb intermittently blocking a jet. You could also have a sticky float valve, but usually they stick open causing a flooding situation. I suggested the clear filter between the pump and the carb, but you could simply take the air cleaner off and look in the sight glass and see if you have fuel. If the carb if full of gas, then there's crap in the carb....rebuild it. If it's out, then I'd go for cleaning the tank. When I've had a fuel pump go on me...at least twice now....it squirts gas out a small hole...kind like the hole on a water pump. Anyway.... Quote Link to comment
mklotz70 Posted September 18, 2007 Report Share Posted September 18, 2007 ya...rebuild the hitachi!!! The kits are only about $17. They are a bit harder to do than the weber, but not much. Heck....send me your hitachi and half the money of a weber and I'll rebuild it for you!!! :) j/k!! Quote Link to comment
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