Unlike GM pumps that often fail while driving, Chrysler pumps almost always keep going once they've started up. When they fail they do not start up. If you hear it run for that first two seconds, the engine should start and run. I suspect when it isn't starting up on its own, it does start from the engine vibration when you squirt gas in. An intermittently non-starting pump would be much more common than a lack of a priming pulse from the injector due to a false reading from a temperature sensor.
When you do catch it not starting and you want to jump the fuel pump relay, use the diagram below and jump terminals 30 and 87. If you see a small spark when you make the connection you'll know the wiring is intact. If there is no spark, suspect worn brushes in the pump motor.
The injector problem I was referring to was not a defective injector. Here again, GM has a huge problem with their injectors. Chrysler hardly ever has a bad one. What can happen to them is the pintle valve leaks. That is not a problem while the engine is running, but when you stop the engine that fuel pressure in the supply line should stay there for weeks without bleeding down. A leaky injector will bleed the pressure down in a few minutes to a few hours. THAT's what can make it hard to start the engine. Since battery voltage is drawn down by the starter, the pump runs slower than normal during engine cranking. As fast as it builds up a little pressure the firing injector bleeds it off right away. Fuel is going into the engine but not enough for it to burn successfully so the engine doesn't start. That's where cycling the ignition switch two or three times before cranking the engine can help.
I couldn't agree more with you about all of the unnecessary, complicated, unreliable computers on newer cars. My daily driver is an old rusty trusty '88 Grand Caravan. You and I only have a very reliable Engine Computer. I've been complaining about the insane computers on newer cars for years.
Saturday, February 26th, 2011 AT 8:39 PM