If the engine cranks but does not start, it may be caused by a tripped inertia switch. Switch the key to "ON" and the fuel pump should be heard running for a second or two. Listen at the gas filler if necessary. The inertia switch is located on the firewall and can be tripped when the parking brake is set too hard and then released. The inertia switch should be reset, and will click when it is reset.
Crank but No Start Condition and No Fuel Pressure on Mazda B4000
Average mileage: 136,271 (54,000–208,000)
25 people reported this problem
1994 Mazda B4000 54,000 mi, Visitor
Fuel pump inertia switch trips often. Will not re-set. Reset Button stays "mashed".
2000 Mazda B4000 127,000 mi, Visitor
Cranks but won't start
1994 Mazda B4000 129,174 mi, Visitor
Truck chugged roughly and died turn key engine turnsover but acts like not enough fuel won't start or idle at all inertia reset is pushed all the way inso pressing doesn't help