I have a 1998 Discovery. It barely accelerates. Not overheating. Basically from a full stop, it just doesn't really accelerate. It also pops and sputters. The exhaust smells really clean. I don't see much vapor... it's just.... well there is very little of it. I am stumped.

My guess is fuel pump.

 

tps sensor could be dead but doubt it. I always say go with the easiest answer first. Is your air cleaner blocked? your fuel filter could be going. If you have clean exhaust it means your head gasket is good as well as your maf and other parts of the emission/air fuel ratio are good to go. there could also be water in your gas so pour a bottle of heat in there see if that works, i mean that's a 2 dollar fix.

 

There is a test valve (looks like tire valve) on passenger side fuel rail, attach a pressure gauge and check fuel pressure, should be 32-34 PSI with pump running. Fuel filter under passenger side rear wheel arch, just where road yuk can make the fittings need some PB Blaster. Common problem is fuel pump wires at connector under rear carpet have corrosion. Fuel pressure regulator on driver side fuel rail rear, has six inch vac line that you don't want to be cracked.

TPS sensor if dead will go to a fixed default. If a scanner is available it will show a TPS position, maybe 9% at idle (it does not go to zero). It should change as you operate the gas pedal. Note value in pix.

Also - in case you doubt the ability of the Rover gauges to be optimistic, note the coolant temp.

 

Hey, everyone. So. I tested the fuel system pressure. It didn't even hit 10 psi. No wonder it was struggling so hard. I first replaced the filter of course and there was no improvement.

Now...

A new fuel pump with AES can cost anywhere from $385 (British Atlantic) to over $1000 (from some of the local import shops I could find). My buddy, Alex, found this website and I gave the guy a call. He basically runs this business out of his home, but he had a -rebuild- kit on hand. The rebuild kit consisted of a filter bag which fits on the end of the pump unit (also included) and two plastic hoses. I can't imagine that the plastic (perhaps silicone) will last very long so I am probably going to rebuild it with marine fuel line and the like next week. That aside, the rebuild worked smashingly. 38 psi fuel pressure when I finished the rebuild.

 

Filter restricton may have been a major contributor to early demise of the pump, so good that you changed it. Post some pix of your handiwork.

 

I actually did take some pictures of the rebuild process of the pump. I am ordering the new fuel line today and I'll rebuild later this week. At that point I'll post a complete step by step on how to rebuild the pump and what to look for.