I have a 1992 ford explorer. It struggles going up hills and slows way down. It wont go past 65mph on flat highway. Since purchasing it i have flushed rear differential, engine oil, power steering fluid, coolant, changed spark plugs, air filter i did gap the spark plugs to spec that the sticker tells me to. I did notice the new spark plugs i bought from the parts store were slightly shorter than the old ones, however the old ones were ac delco so I figured those were wrong for a ford. I also checked the back pressure before the cats and it does not have any according to the gauge i just bought at harbor freight. When i removed old spark plugs the threads had oil on them. When i bought and drove it home it could go much faster.
Hopefully not transmission slipping or anything. You sure the cats aren't clogged?
@mrrangerzr1
Not 100% sure as I'm having trouble removing them, the flange is stuck pretty good. I'll work on getting getting cats off and see if that improves anything. Thanks
If it's fuel injected, check fuel pump pressure or clogged injectors. If carbureted, check fuel pump pressure, dirty air cleaner or dirty fuel filter.
@doc
That's interesting you say it could be fuel, it's a 1992 that i have no history on and I recently ran it to almost completely empty, wonder if something got sucked out of the fuel tank. Thanks.