20 Most Recent 1991 GMC Safari Questions & Answers

Info in the link and in general in the videos https://www.google.com/search?q=1991+GMC+Safari.+compression+test

inside gas tank, access through the top of tank

Did you push the button in the dash area to make it switch?

with a multimeter test the voltage from alt to bat should be 14.2 volts test battery after a charge should be 12-13 volts not disconnect negative from battery and put your multimeter on fusable 10 amp and do a draw or drain test plug the black cable from the multimeter to the battery and the red cable from multimeter to the cable neg black on the car side cable unplugged from battery make sure keys are out of the ignition and the doors closed and nothing on in the car you should see .05 mv to .03 mv if you have more after a 30 mins test or 1 hour test then you have to find the drain on battery to find this you take out fuse at a time to see if it chages repeat not all the fuses at once 1 at a time

no check engine on if so scan for codes could be bad crank sensor low oil for the sensor bad coils bad plugs compression test would help to solve if motor not damaged

when is the last time you had your ignition system cheked for spark plug gap or rotor wear or roto cap cracked

Engine stall or RPM fluctuates at idle.

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control

ignition timing is incorrect reset the i.timing to the manufacturer specification.2) tes the fuel pump pressure with a pressure gauge, If pressure is NOT within the manufacturer specification , replace God bless you

check for crankshaft sensor or camshaft sensor,or immobilizer ,or ignition switch failure- use the spare key.

The first thing a mechanic would check is for power and a ground signal for the coil. The pickup coil in the distributor sends a signal to ground the coil. The coil sends the spark to the distributor cap thru the rotor to the plug wires.

check power going to blower if u have power in all blower selections then motor is bad or blower wheel could be bad.if u don't have power in all selections then its probally the switch

Could be a problem with the connector at the back of the cluster, or the printed circuit board.

Rich fuel mixture or lean, either one gives out "fumes"