QuestionQUESTION: Hi Roland. I have a 2001 Sebring convertible with 2.7L. The fuel pump isn't working. It will run briefly when I spray starter fluid in it. I got new fuel pump from Ebay and still no luck. I checked the fuses and relays, all good. I have another sebring I took fuses out of and relays and still nothing. I checked the wires at fuel pump and nothing there. I even hot wired to fuel pump and nothing. Maybe new pump is bad but can't understand why no voltage at green white wire going to the pump. Should it be 12v there? Does the engine have to be cranking to get voltage at pump? Does the regulator have anything to do with when it will get voltage?
ANSWER: Hi Paul,
Fuel injected cars have a fire safety circuitry that automatically shuts off power to the spark plugs and fuel pump if the engine stops rotating as foretold by the engine rotational sensors ceasing to pulse. There should be power to the pump for just a second when you turn the key to the run position. Then it will get power again so long as you are either cranking if over or it is running on its own. To jump power to the pump put 12v on the middle pin of the pump relay socket by jumping from the rear pin to that pin (16 to 15). Fuse 8 provides the voltage on pin 16 and fuse 23 is needed to close the relay internal points.
So start by listening outside the tank to see if it hums for a second when a helper turns the key to run. If so, then the pump and the safety circuit are working. But then if you don't get any fuel pump sound or pressure then the first thing to verify would be the rotational sensors of the engine. If you can borrow a fault code reader to plug in under the dash where there is a socket next to the steering wheel you could find out if the crank sensor (code 0320) or the cam sensor (code 0340) were not working. Or you can check the sensor with a voltmeter using a socket on the crankshaft pulley bolt to turn the engine by hand (with the ignition switch in the run position) and measuring the voltage pulsation of each sensor which 5v to 0.3v several times for each rotation of the engine. The wires to measure are for the crank sensor between the gray/black and the black/light blue, while for the cam sensor between tan/yellow and black/light blue (which are 32 and 43, and 33 and 43,respectively) at the pcm.
Please read the PS below.
Thanks,
Roland
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QUESTION: That's a lot of good info and it gives me more to look at. I did have my son listen at gas tank and he heard nothing. I know fuse 8 is good. I'll look at fuse 23 but I'm pretty sure I looked at all fuses. It does start with starting fuel so that means plugs are firing. I'm not sure what you mean about pin 15 to 16. On the relay it has pins with numbers 30,85,86,87,87a. I know the pin 30 is hot with key on. I know for 87 and 87a one does not have any connector in fuse box to attach to. My other sebring is same way. I kinda thought I should raise whole fuse box to see if connector had fallen down. I have a code scanner but no code about sensors. I get one about DTC defintion unknown. I'll have to look it up again. I forget the code number. I once had code that left and right side fuel rail high pressure. I should tell you at beginning of problem I drove it to work just fine. Got off work and it didn't start. Got ride home. Next day after work it started right up and was driving it home on interstate. Went to pass slow car and accelerated hard and it died. Had it towed home. Sprayed starting fluid in it and it starts right up for few seconds. Do it again and it starts right up for few seconds. I had to work today and haven't been put to try anything but I'll go over what you sent me. I let you know later. Thanks a bunch.
AnswerHi Paul,
When the fuel pump relay closes: pin 30 is connected to pin 87 which should fire up the fuel pump. So you could temporarily jump across those two pins in the socket (the rear pin to the middle pin) which should cause the pump to run, then try to start it. Listen for the pump to run when you do the jump.
If it works then the question is why isn't the relay closing from 30 to 87. Of course you don't want to leave that jumper in place both because it will drain the battery and also because it circumvents the fire safety purpose of the circuit.
If you would rate and nominate me I would be most appreciative.
Roland
