1997 Dodge Stratus

Fuel pump and filter are the last things to suspect and highly unlikely to be the cause of stalling on Chrysler products. Did you check for spark after the engine stalled? The Engine Computer has to know when to fire the spark plugs and injectors, and it has to know when to turn on the fuel pump and ignition coil. It knows that when it receives pulses from the crankshaft position sensor and the camshaft position sensor. Either of those commonly fail when they get warm and will work again after they cool down. The computer will usually set a diagnostic fault code in memory too that will tell which circuit has the problem, not necessarily the defective part.

The fuel pump, ignition coil, and injectors get their power from the automatic shutdown (ASD) relay. The Engine Computer turns that relay on for one second after turning the ignition switch to "run", then it turns it on again during engine rotation, (cranking or running). You should have a separate relay for the fuel pump that turns on at the same time as the ASD relay. You might try switching it with a different relay.

Check for spark too when it doesn't start. If there's no spark, there's no point is checking for fuel pressure.

The pump will only run for one second after turning on the ignition switch so you're going to have to listed by the tank while a helper turns the switch on. Unlike GM pumps, Chrysler pumps almost never quit while they're running. It's much more common for the sensors to become heat-sensitive when they start to fail.

The relays are in the fuse box under the hood.

Remove the fuel pump relay, then jump the contacts in the socket with a stretched out paper clip. At that point you can check for voltage without having to turn on the ignition switch. Jump terminals 30 and 87 or the two with the arrows, depending on which type of relay is used. I only have a '98 service manual but it should be the same. It shows the smaller relay on the right for the fuel pump.

If the pump doesn't run with the jumper, measure the voltage on it. If there is 12 volts present, there is a break in that wire, the connector, or there's a problem with the pump. If there is no voltage on the jumper, check fuse 8, a 20 amp fuse.

If your engine has a fuel pressure test port, remove the cap and press the valve to see if there is pressure. It would be better if you had a gauge. There should be around 45 - 50 psi.

Nothing in the fuel supply system is monitored by the Engine Computer so it won't set fault codes or turn the Check Engine light on in response to problem with it.

The fuel pump gets its voltage from either the automatic shutdown (ASD) relay or a separate fuel pump relay tied in with the ASD relay so it turns on at the same time, (I can't remember which). The Engine Computer turns the ASD relay on for one second when you turn on the ignition switch. That is to insure fuel pressure is up and ready for starting in case it bled off while sitting for days or weeks.

Next, the computer turns the ASD relay on again during engine rotation, (cranking or running). It knows that because it receives pulses from the crankshaft position sensor and the camshaft position sensor. Those signals synchronize spark plug and fuel injector firing times too.

The easiest way to tell if the ASD circuit is working is to grab a test light or digital voltmeter and measure the voltage on the dark green / orange wire at the coil pack connector, any injector, or either small terminal on the back of the alternator. Set it up so you can see it from inside the car, or have a helper turn the ignition switch for you. If you don't see voltage on that wire for the first second, the relay has a bad contact inside or the fuse feeding it is blown. Some digital voltmeters respond too slowly to pick that voltage up. That's one place where a test light might give better results. If you don't see voltage on that circuit for the first second, you likely won't see it either while cranking the engine, however, if you DO see voltage there, that proves the relay is good and the computer has control of it.

If you don't have voltage for the first second and during cranking, troubleshoot the relay circuit. If you do have voltage, you should be hearing the fuel pump too. The next thing would be to check for voltage the same way right at the connector on the tank.

If you have voltage for the first second but not while cranking, you won't have spark or injectors firing either because both circuits get their voltage from the ASD relay. That's the time to suspect the cam or crank sensors. Also, if the timing belt has jumped two or more teeth, those two sensors will be out of synchronization and the computer will turn off the ASD relay to protect the engine from valve damage. At three teeth off, any open valves will be hit by the pistons. At just one tooth off, the computer will set a diagnostic fault code in memory and will turn on the Check Engine light but the engine will still run poorly.

I assume that means you never found any voltage on the dark green / orange wire. First check for voltage on fuse # 5, a 20 amp under the hood. If you have voltage there and the fuse is good, remove the ASD relay and check for voltage on all four pins. (The middle one isn't used). Two terminals in the socket should have full battery voltage all the time.

If you have voltage at the fuse and relay, we need to determine if the computer is turning the relay on. One way to do that is to pop the cover off and reinstall it that way, then watch for the contact to move when a helper turns on the ignition switch.

If you're not getting voltage for that one second burst it would appear the computer isn't turning on the ASD relay. I'd like to verify that everything else is working so we don't take a wrong turn. Look at the diagram above and find terminal 86 on the left side. When the relay is removed, that terminal should not have voltage. Stick a short piece of wire or a stretched out paper clip in that terminal, then plug the relay back in. Be careful to not wedge that wire in too tightly because the terminal could become stretched out and make poor contact later. Now that the relay is in place, there SHOULD be voltage on that terminal. If that's what you find, (no voltage UNTIL the relay is installed), use a jumper wire to ground that wire. The relay should click on. Your jumper wire is doing what the computer is supposed to be doing.

With the relay turned on, test for voltage on the dark green / orange wire. I think the fuel pump should be running too but if it isn't, I'll have to search further in the service manual to see if the pump relay is on the same circuit.

Yup. What I typed, "86" vs. "85" is backwards and you grounded the correct terminal. I recently changed my drawing and description because I thought I had made a mistake. Apparently there is a mistake in one of my service manuals.

This proves the switched circuit is working. If the computer is not turning that relay on for the first second, something is wrong with the computer. Before condemning it, make sure all of the power feeds and grounds are okay. Both computer plugs are listed as "black" so you'll have to figure out which is plug number one by the wire colors. Pins 41 through 50 are in one of the outer rows. Pin 46 must have 12 volts. That's a red / tan wire.

In the other plug, pin 20 is on the end of one of the two inner rows. It is dark blue / white and must have 12 volts when the ignition switch is in the "run" position. Check both of those wires.

If I had a computer in my back pocket I would throw it in as a test, but the next best thing is to eliminate all other likely possibilities before finding another one. First measure the voltages on the pins I mentioned previously. Pin 46 must have voltage all the time, and pin 20 must have voltage when the ignition switch is in the "run" position. There has been a lot of trouble with overheated contacts in the ignition switch and with overheated terminals in the connector and the connector body melts, but that typically affects the heater fan / power windows circuit. I don't recall ever replacing a switch or repairing the plug for a no-start condition.

If you find 12 volts on both of those wires, we should check the ground wires next to be sure they all have 0 volts on them. If it comes to that, I'll dig out the service manual and figure out which pins to measure on.