Car will only run off a squeeze bottle

ELOSO5442

MEMBER
1994 PLYMOUTH ACCLAIM
2.5L
4 CYL
2WD
AUTOMATIC
56,000 MILES

Vehicle sat for a decade. New plugs, wires, distributor, fuel pump, fuel sender, fuel filter, fuel injector, battery, and oil change. One of everything really. Car fired up and ran really well for about two days, then one day it was just idling in the drive way and stalled as though it had ran out of gas. I slide underneath and sure enough I do not hear the fuel pump anymore. If the car is cranked and I feed the throttle body off a squeeze bottle it will run so that says we have spark and air. I read the trigger voltage at the relays and the voltage does not cycle, it is a solid twelve volts at the blue yellow wires running between what I believe to be the fuel relay and auto shut off relay. If the computer is reset (battery disconnected for thirty minutes or so it will run for about thirty seconds. I am at a loss. Any input is appreciated. The tank was washed out and I blew the lines out before installing the filter and pump as well.

1 Reply

CARADIODOC

MECHANIC
33,870 POSTS

The fuel pump is designed to turn off when the engine is not rotating, (cranking or running)? You have to listen for its hum for one second after turning on the ignition switch. If you do not hear that, you have already proven you have spark. The ignition coil and injectors get their twelve volts from the automatic shutdown, (ASD) relay, so we know that is working. The fuel pump relay's coil is in parallel with the ASD relay's coil, so it should be turning on at the same time. The fuse link wire feeding the fuel pump relay's contacts has to be okay too because it also feeds the ASD relay. That eliminates the possibility of a corroded and intermittent connection, but not a corroded splice.

Since you are already down by the wires, check for twelve volts on the fuel pump relay's pair of dark green/black wires. A test light works best for this but you can use a voltmeter too. You should see twelve volts for one second when you turn on the ignition switch, and again during cranking. If you have that, you'll need to check on that wire at the pump. If it is missing at the pump, there is a break in that wire or a corroded connector terminal. If you have twelve volts at the pump, but the pump does not run, there is an intermittent break in the black ground wire, or the pump has a bad connection. If it would be an old pump, worn brushes are a common cause of intermittent operation, but Chrysler pumps rarely stop running once they have started up. GM pumps typically fail while you are driving, but Chrysler pumps fail by failing to start up. With worn brushes, you can often get a Chrysler pump started by banging on the gas tank while a helper cranks the engine.