runs poorly when hot - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

tamochin · 09-06-2009, 10:45

1999 ford ranger 3.0

truck runs fine when it is cold but once it gets up to operating temperature it loses about 1/3 of its power. Under a load like going up a hill I notice alot of pinging. I need to shift down even on the smallest of grades. If I step on it like I want to pass someone it pings like crazy and ultimately displayes very little power all the while pinging like crazy. Any suggestions?

**Bert** · 09-06-2009, 20:49

Have you changed the fuel filter? They can cause a lean ping if they're restricted. How old are the spark plugs? Another thing is to get a MAF cleaner and clean the MAF.

**360ci** · 09-15-2009, 16:04

If the engine is knocking under load - I would advise against giving it any more fuel or you'll have more problems on your hands. Still, even if the plugs aren't all that old (say two years with lower miles), pull one or two out and make sure they look OK (not burnt/electrode missing, etc). If the fuel system checks out OK, get a compression test done.