Engine Performance problem
1997 Other Isuzu Models 4 cyl Manual
Truck recently started losing power while driving. Thought it might be bad gas. Spark plugs replaced. Fuel filter replaced. Fuel pump replaced. Battery tested - good. Alternator tested - good. Some hoses replaced. Belt tensioner replaced. It is still losing power while driving, or it won't even go over 35 mph. Any thoughts?
What does the engine sound like? If it is missing then it is usually in the ignition. If it feels like the truck is driving through sand and surges but perks up when you put it in neutral and let it idle for a minute it is probably in fuel system. If it doesn't even like it in neutral it may not be getting enough air through the filter and out the exhaust. If the engine sounds fine but just doesn't make you go faster it may be in the drive line.