Occasional low idle on start-up and jerking on gearing to 1st

mazda
b2300

#1

Hiya,

my 2002 standard B2300/4cyl Ford Ranger sometimes idles very low on start up, and it will jerk as though it were coughing when i engage in 1st and give it a tiny bit of gas. the jerking stops if i give it proper gas. oh yeah and about the low idle, it’s only after starting, not at stops, and once i give it a bit of gas it pops right back up to 1800ish and drops to 1200ish as it should. this happens less this summer but i’m afraid it will happen more often as the weather changes and i want to deal with this before winter hits. it feels like something is clogged… but what do i know! my baby’s got 119 000km and i bought it a year ago, no idea of its maintenance history.

fanks!


#2

Since you have no maintenance history on the vehicle, start with the basics: spark plugs, distributor cap & rotor (if the truck has them), spark plug wires (again, if the truck has them), air filter, PCV valve, fuel filter (if serviceable), throttle body cleaning. Also, carefully inspect all vacuum lines and fittings.


#3

You state it seems fine if you give it proper gas. That leads me to think you might be trying to start moving and just not giving enough gas. But NYBo is correct that a tune up is in order. Also if this thing has a timing belt I would replace it soon as to not destroy the engine.


#4

Have your shop check the idle rpm measurement, it might just be idling a little slow is all. If it is, they’ll likely know what to do to correct it. The throttle mechanism may be sticking a little, needing a cleaning.


#5

Maybe a sticky Idle Air Control valve or dirty air passage for that valve.