My '98 Frontier has always run like a top, but lately it has developed a new problem, it hates hills. We are not talking little bitty hills here, but super steep San Francisco type hills. It acts as if it is starving for either fuel or air. It flat will not go up a steep hill, it dies, might not even restart, requiring backing down, which if often tricky. My mechanic says that the computer tests out just fine. We have done a super tune up, given it new plugs, plug wires, everything in the ignition field, fuel filter, everything we can think of, but it still chokes on steep hills. The mechanic thinks that it is either a computer glich that doesn't show up on the test, or something loose in the cat. converter that falls back on hills and plugs it. Since both of those items are kindasorts expensive, before we spend the money, has anyone else had a similar problem???
I'd put my money on fuel system problems. A converter intermittently plugging wouldn't just shut the engine down cold like that -- because converters rarely completely 100% plug up. But every now and then, you'll get the baffles in the fuel tank coming loose, which doesn't hold the fuel near the pump sock. Does the problem occur even if the fuel tank is plumb full?
I'd put my money on fuel system problems. A converter intermittently plugging wouldn't just shut the engine down cold like that -- because converters rarely completely 100% plug up. But every now and then, you'll get the baffles in the fuel tank coming loose, which doesn't hold the fuel near the pump sock. Does the problem occur even if the fuel tank is plumb full?
Yesterday we were less than 20 miles from the station, where we filled the tank to the top. It sure acts like fuel or air starvation, but we just can't figure out which. If it was carburated I would suspect a float or something, but it is injected. Fuel filter was replaced, so it isn't that...???...
Yesterday we were less than 20 miles from the station, where we filled the tank to the top. It sure acts like fuel or air starvation, but we just can't figure out which. If it was carburated I would suspect a float or something, but it is injected. Fuel filter was replaced, so it isn't that...???...
So even after you filled the tank plumb full, it still sputters on steep hills?
Other thing I would think of is a fuel pressure regulator, but that's usually not incline-dependent. Excepting the pump, there's really nothing to go wrong with the fuel system, especially not something that only happens on inclines. My money is still on the tank/pump/sock.
So even after you filled the tank plumb full, it still sputters on steep hills?
Other thing I would think of is a fuel pressure regulator, but that's usually not incline-dependent. Excepting the pump, there's really nothing to go wrong with the fuel system, especially not something that only happens on inclines. My money is still on the tank/pump/sock.
Do you know how the in-tank fuel pump in constructed? I once had a '75 Toyote P/U that developed a problem that turned out to be a filter attached to the pump. It had a sponge-like affair inside of a "mesh" bag to keep the bag from sucking flat. Over the years the sponge thing turned onto what looked like coffee grounds and would temporarily block the filter intake. Does the Nissan pump have something like that???
Do you know how the in-tank fuel pump in constructed? I once had a '75 Toyote P/U that developed a problem that turned out to be a filter attached to the pump.
That's the "sock", and all in-tank electric pumps that I know of have this. It could be clogged or blocked on yours. I think you should drop the tank and check it out. Check for loose baffles and also check that sock.
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