1999 Mazda b3000 • 6 cylinder 4WD Manual • 96,000 miles

Sorry, this is a repeat question, I had some computer issues as well as vehicle issues. I have a '99 b3000 Mazda, it lacks power in 4th and 5th gears. The engine hits about 2500 rpm and then it takes a while to climb over the hump. I have replaced the fuel filter and regapped the plugs. Also, put some Lucus fuel injector cleaner and mid-grade gas in. It seems to be getting better, but has a long way to go. The clutch is not slipping. What else could it be?
Brian Naragon
November 14, 2010.

Was the ignition timing checked?
Did this problem occur after any repairs?
Have you checked the throttle operations? Is it opening fully when pedal is fully depressed?

Nov 14, 2010.
No, the timing was not checked. No, the performance did improve after gapping plugs and changing fuel filter. Still much room for improvement. No, I havn't checked the throttle, but it seems to be okay in 1st-3rd.

Brian Naragon
Nov 14, 2010.