I have an old truck engine that is sounding like it is running kind of high rpm when I am stopped at a traffic light and in neutral.
What are some reasons possibly for this?
2007-03-28 15:20:11 · 10 answers · asked by Charles R 1 in Cars & Transportation ➔ Maintenance & Repairs
IT IS A 1993 TOYOTA 4X4 PICK UP TRUCK T100.
IT HAS A 3.0 V6 ENGINE.
2007-03-28 15:30:33 · update #1
IT IS FUEL INJECTED .
2007-03-28 15:31:55 · update #2
Hi
High idle could be caused by a leaking vacuum pipe, a sticking idle control valve, a sticking throttle lever or butterfly, a sticking or damaged fuel pressure regulator, a faulty coolant temperature sensor, any number of things.
If your vehicle is fitted with O2 sensors then one of them could be switching too low and so causing a higher idle than usual, but this would only be apparent once the engine had warmed up.
The first thing to check is all of the vacuum pipes (EGR, fuel pressure regulator, brake servo hose, etc) basically any pipe that is connected to the intake or throttle body because these are popular cause of high idle.
Best of luck
Geordie
2007-03-28 22:58:55 · answer #1 · answered by Grizz 5 · 0⤊ 0⤋
If you sit in neutral or park and push the brake down and the idle gets higher listen for a leaking air sound down by the brake pedal. If you do hear this you have a bad power brake booster leaking air. Another way to test this is to plug the hose going to the booster and push the brake pedal and see if the problem stops. If it does stop then the booster is bad. DO NOT DRIVE THE VEHICLE WITH THE VACUUM LINE DISCONNECTED FROM THE BOOSTER.
2007-03-28 15:34:51 · answer #2 · answered by eightup23 3 · 0⤊ 0⤋
If your truck has a carburetor #1. Make sure the fast idle cam has dropped down all the way after warm up. #2. Check for vacuum leaks wit a vacuum sniffer. Hopefully there are none. #3. turn the single idle speed screw counter clock wise a quarter of a turn.
2007-03-28 15:31:17 · answer #3 · answered by Country Boy 7 · 0⤊ 0⤋
Brokeing Vac lines carb need to be fixed timeing maybe off
2007-03-28 15:26:19 · answer #4 · answered by davedebo198305 4 · 0⤊ 0⤋
try the simplest first a new throttle spring or adjust the cable to the revs drop
2007-03-29 06:23:34 · answer #5 · answered by Anonymous · 0⤊ 0⤋
several things - too rich a petrol/air mixture or a faulty choke ,sticking on - faulty lambda sensor - sticking throttle cable.
2007-03-28 15:29:45 · answer #6 · answered by baldz 2 · 0⤊ 0⤋
sounds like a vaccum line...but you did not specify year of vehicle...could be an air/gas sensor if it has one...good luck...
2007-03-28 15:29:26 · answer #7 · answered by Michael K 5 · 0⤊ 0⤋
maybe a vacum leak leave engine on and see if ur can hear it
2007-03-28 15:26:30 · answer #8 · answered by Anonymous · 0⤊ 0⤋
COULD BE A STICKY CHOKE REFUSING TO CLOSE
2007-03-28 22:04:01 · answer #9 · answered by Anonymous · 0⤊ 0⤋
your choke isnt opening up all the way
2007-03-28 15:28:57 · answer #10 · answered by mobile auto repair (mr fix it) 7 · 1⤊ 1⤋