Car cranks, won't start. Need help.

[CincinnatiKid05]

Okay. So I have pulled my fuel pump. It works when hooked up directly to a battery or if I leave it in the tank, then take the cover of the fuel pump relay off and push it manually then I can hear the pump. However when I try to start it and get it and turn the key to on or start, I do not hear the pump prime. I have looked around on the site and people do not post the fix, but i think others have had the issue. Please help! Thanks so much

 

[MrGiggles]

Does the relay click? I believe the contacts under it are known to fail.

 

[CincinnatiKid05]

I do not think the relay is clicking. I just had to push the contract manually and it kicked the fuel pump on. I switched the relay out though and it didn't change anything, so what do I do now?

 

[MrGiggles]

Get a test light or multimeter and see if there is power going to the relay coil. If there is, replace relay.

The fuel pump will not prime if there is a crank sensor fault too, among other things that can be found in the service manual.

 

[pcb]

The fuel pump will not prime if there is a crank sensor fault too, among other things that can be found in the service manual.

Make sure you check your gap and wiring harness for shorts and opens.

You may not throw a code if getting a bad signal from your crank sensor.



I remember another guy had a crank but no start condition... His plugs would fire twice then no spark.

It turned out to be his crank sensor but he threw no code.

 

[mazdadude]

Just throwing in another possibility... IGNITION Switch? Wasn't there a recall on the IG switch?

 

[CincinnatiKid05]

Thanks for the ideas, I have not had time to run the tests on those parts yet, I will get to that later tonight or tomorrow morning. I have tried 2 fuel pump relays and neither of them changed the issue, so how do I use a multimeter to see if I am getting power to the relay coil? If it is testing the slots that the relay presses into, which ones do I need to test since there are 4 prongs?

 

[MrGiggles]

Thanks for the ideas, I have not had time to run the tests on those parts yet, I will get to that later tonight or tomorrow morning. I have tried 2 fuel pump relays and neither of them changed the issue, so how do I use a multimeter to see if I am getting power to the relay coil? If it is testing the slots that the relay presses into, which ones do I need to test since there are 4 prongs?

I'm not exactly sure which relay the P5 uses, but I'm assuming it's this style, minus one prong. STA and E1 are your coil wires. B and FP are your in and out.

 

[CincinnatiKid05]

Awesome, thanks for that picture. I just went out and checked it and I am getting right around 12 Volts of power through those 2 prongs, but I have tried 2 different relays that have both tested fine and I do not hear the fuel pump prime when either of them are plugged in.

 

[pcb]

Test for voltage at the fuel pump connector.

 

[MrGiggles]

Awesome, thanks for that picture. I just went out and checked it and I am getting right around 12 Volts of power through those 2 prongs, but I have tried 2 different relays that have both tested fine and I do not hear the fuel pump prime when either of them are plugged in.

Constant 12v? Should just be a momentary pulse after you switch the key on. If it's constant, those must not be the right terminal.

 

[pcb]

Constant 12v? Should just be a momentary pulse after you switch the key on. If it's constant, those must not be the right terminal.

Unless the car is waiting for the system to reach full pressure... Which it won't if the relay is removed ???

 

[CincinnatiKid05]

Yep, I was getting a constant 11.87 volts from both of the terminals. And also, my crank sensor had 545 ohms of resistance. Although, I am confused of how to test the crank circuit and how that process works.

 

[pcb]

 

[pcb]

... Although, I am confused of how to test the crank circuit and how that process works.

 

[pcb]

... And also, my crank sensor had 545 ohms of resistance...

It may have proper resistance but it may not be putting out a signal...

The best way to check it is to use an oscilloscope at the input on the ECU. (it's a very small signal and a regular voltmeter won't pick it up)

 

[CincinnatiKid05]

Alright, so it seems like the fuel pump relay is working fine and when I manually press it with the key in the on position, the pump primes and runs, but it is still not firing up.

 

[i12drivemyMP5]

It can't be the crank sensor. That has already been dismissed once........

 

[pcb]

I remember another guy had a crank but no start condition... His plugs would fire twice then no spark.

Make sure you are getting continuous spark when you are cranking your engine to rule out a crank sensor issue.

 

[mazdadude]

Make sure you are getting continuous spark when you are cranking your engine to rule out a crank sensor issue.

Yes! I would have a spark plug out, checking for spark, and my nose to the spark plug hole and spark plug to sniff for gas after cranking...

If you got fuel and spark, just need timing and compression..