Crazy Ignition Problem


#1

To start my 1994 Jeep Cherokee, I must turn the key to the notch before the crank and wait until I hear a noise under the hood. Then when I turn the key all the way to crank the engine, it will start.
What is wrong and how do I fix it??
Thanks!!


#2

You could have a leaking fuel injector, but then it would be hard to restart your engine right after shut off or there would be a cloud of black smoke coming out the tailpipe if it did restart.

You could have a defective fuel pressure regulator that allows the fuel to be sent back to the tank and you have to wait until the fuel rail is pressurized before you can start it.


#3

My first guess is the ignition switch is failing.


#4

My hunch is I might have a defective fuel pressure regulator as the wait (to hear the noise) is longer during colder weather…since Pressure is directly proportional to Temp (PV=nRT).
Any way to test for this, or do I buy the part and stick it in? Also, is this an easy part to install. I have worked on cars a bit when in college, but that has been a while.


#5

I suggest you don’t replace anything until you figure out for sure what is cauing the trouble. Guessing at parts replacement usually results in needless parts being replaced.


#6

There is one simple test, but not definitive. Pull the vacuum hose off the regulator right after shutting down the engine. If fuel squirts out, its bad.