Will a bad CPS stop the fuel pump from working? The fuel pump rarely activates in the ON position, and the car does not start. When the pump activates, the car starts, but within 10 seconds, dies. When attempting a re-start, there is no fuel pump sound, and it wont start. I have a new battery, re-soldered the RCM, installed a new fuel filter.

 

You are probably making the wrong assumptions here, if the fuel system is pressurized then you will not hear the pump until some gas has been used. So a restart will not require the pump to come on, or if it does the sound will be hidden by the starter noise.The CPS is not a contributing factor in the fuel pump operation directly.

 

If you are having trouble it is best to let people here know all the relevant facts, and I do mean all.

 

1. January engine sputtered and died in driveway
2. Car would restart with a Jump battery
3. Replaced battery with new Bosch. Car Started
4. Drove for about 10 min and car started sputtering; came home.
5. Engine died in driveway; could not re-start
6. Checked for codes; but none because I hadn't driven far enough since changing battery
7. February - Re-soldered RCM board.
8. Car Started, revved up and idled great.
9. Ready for a test drive--NOT. Engine died in driveway.
10. March - Replaced fuel filter (Bosch)
11. Car started and idled fine, but died as soon as I used the accelerator.
12. Have not been able to start the car since

 

I'm pretty sure that any codes will not be affected by a change in battery.
Do you have any fuel pressure?
CPS and crankshaft position sensor can cause problems like this.
Is the check engine light on?
I guess it is possible the fuel pump has died, check for flow with a gauge or release the valve and see if any comes out.
How many miles on the car?

 

The battery had been out for about 3 weeks before replacement. code reader said 'drive car to re-generate codes.'
The check engine light had not been on prior to the engine dying; but all lights are on until it starts; which it wont do.
60,210 miles on car
I just checked fuel pressure by removing line to fuel filter. fuel just drips out of filter. There was not a gush.
Oh, no fuel pump sound after replacing lines.

 

If you don't mind, where is the release valve? that would have been much easier I believe.

 

Lie down on the ground by the fuel pump / filter and have someone switch the ignition to just before start.
If you do not hear the pump run, then turn ignition off and go to the front of the fuel rail on the engine right side, remove the black plastic cap and press in on the Schreader valve ( covered with a rag so you don't get sprayed if there is pressure ).
When fuel stops flowing, do the listen test again.
If still nothing, then one of two things :
1. the RCM is not supplying 12v to the pump.
2. the pump has 12v, but won't run ( a voltmeter might come in handy for this )

 

No fuel from filter = no fuel from valve.
There is a relay in the RCM for the fuel pump.
Open the RCM after doing ala_xfires tests and look at it.
You do have fuel in the tank?

 

No fuel from valve. And then, no sound from fuel pump. Even though when its working, I can hear the pump from the drivers seat, I had a helper turn the ignition on while I listened from underneath.
I will be checking voltage, next.
First at the fuel pump; then at the RCM.
Where is the best spot on the fuel relay in the RCM to check voltage?

 

First, Yes, I have a 7/8 full fuel tank.

NO voltage at the fuel pump; which brings me back to the RCM and CPS. I cant figure out how to check the voltage at the fuel relay. I have read that a faulty CPS can stop voltage at the relay. Is this true?

 

RCM connector pin-out for fuel pump : ( CPS has nothing to do with the RCM that I am aware of )

 

NOTE: you can always send the RCM to tighed1 and he'll fix it for a nominal fee.
His normal fee is $10 for a re-solder job, I had one I couldn't figure out that he fixed for $20.
It had a flaky engine relay, even though everything metered out OK. I don't know how he isolated it,
but then he's an electronics genius and I ain't.

 

While looking for the correct pin in the service manual, I found the following:

"OPERATION
The fuel pump relay supplies battery voltage to the fuel pump. The fuel pump relay power circuit contains a fuse.
The fuse is located in the relay control module. Refer to the Wiring Diagrams for circuit information.
The PCM controls the fuel pump relay by switching the ground path for the coil side of the relay on and off. The
PCM turns the ground path off when the ignition switch is in the Off position. When the ignition switch is in the On
position, the PCM energizes the fuel pump. If the crankshaft position sensor does not detect engine rotation, the
PCM de-energizes the relay."

 

Thank you both so much for your attention to my problem. I re-soldered the board on the RCM last month.
I'll be replacing the CPS next since its a $70 part as compared to a $400 part.

 

Guess I was wrong about the CPS not having any relation to the RCM.
But technically the CPS feeds the PTCM, which then controls the RCM.
My thinking was not broad enough, I apologize.

 

Never apologize, that's my motto. Some see it as a sign of weakness.
I said it was not directly a contributing factor, that's good enough for me.

 

The RCM is cheaper than you think. Mine was, I can't remember now, but under $200.00 and it was new in the box. Copy the part number off your RCM, google it and pick from the scores on ebay.

Les

 

I replaced the CPS. No Change. I now have a spare which from what I read is a good thing.

There is NO voltage at the fuel pump, OR across the fuel pump relay fuse. There IS power to the RCM. I checked voltage across the other RCM fuses.
Is this a symptom of a bad relay or RCM circuitry, or should I check something else?

I just also re- re-soldered the board on the RCM; what the heck, right? No change.

And, Yes, I found several 'in the box' RCM's for $175 or less. This seems like the next logical step; but I don't think I need a spare one of these.

Any other Ideas, or should I go for the RCM?

 

I attempted to repair my RCM myself. Didn't work for me either. I purchased one off of ebay and that fixed my no start problem.

Les