Need help ASAP. Fuel Pump problems

[rio95]

Well, I put in a walbro a week ago. The car ran fine for about a week, then do I could not get the pump to do anything. It's like there is no power going to it. I have checked both fuse boxes and the intertia switch and still no luck. The only thing I can think of is possibly the CCRM. When I turn the key on, everything workis fine, except for the fuel pump coming on. Also, when I first turn the key on sometimes the CCRM will make a vibrating noise for about 10 seconds then stop. Is this normal?? Any ideas???

 

[mo_dingo]

Check to see if you are getting 12V at the pump with the ey on acc. If you aren't, you likely have a bad connection somewhere.

Check the connectors and make sure they are all crimped well (wires don't pull out of connectors), check wires any damage.

You may have got a bad pump. If you have 12V at the pump, and the connections are good, your pump is likely dead. Put your stocker in for the mean time and get another pump on warranty.
Scott

 

[rio95]

Yeah, I planned on trying to check the voltage. I haven't really looked, but I think I should be able to get a DMM at one of the wires. I'm thinking that I'm not getting any power back there but we'll see.

 

[rio95]

Well, I think I tested the voltage correctly and found that I have voltage. This is how I did it, I unplugged the connector that plugs into the wiring harness that goes to the fuel pump, put the pos. side of the dmm on each of the four pins in the connector and had someone turn the key to on. When the key was turned, I read voltage at two of the four pins. I'm assuming two hot ones and two grounds. I read 7.88v and 8.25v. Is this how you do it or do I leave it plugged in when I test it??


thanks

 

[rio95]

I just borowed a friends CCRM and it still didn't work. I'm going to drop the tank right now and keep trying.

 

[mo_dingo]

I don't know the wiring diagram for the fuel pump. Look it up on the haynes manual, it should tell you.

You likely have a bad pump, but that is still up in the air until you verify which wires should have power and which should not.

I am thinking you should at least see 12V at one of the pins. But I am not sure.

Scott

 

[HISSIN50]

im with Scott, though i am very familiar with fox set ups (no CCRM). the pump does need 12 volts. if there is a fusible link for the feed to the pump, i would check it for having partially burned (showing some volts, but unable to flow any amps).

good luck.

OT: Scott, how is it running?

 

[rio95]

I forgot to add that when I tried my friends CCRM weirds things started to happen. When I would try to prime the pump, my fan turned on, my tach shot up to 5000rpms, his CCRM was making a really loud vibrating noise and my gas guage shot up to full. I hope I didn't ruin his CCRM or mine for that matter. They're not cheap.


Anyways, I think I am going to try pulling codes tomorrow and/or drop the tank. I think something electrical is fried instead of the pump just being bad. Also, I don't know of any fuse link in the wiring. But if there is, that would make complete since.

 

[HISSIN50]

I forgot to add that when I tried my friends CCRM weirds things started to happen. When I would try to prime the pump, my fan turned on, my tach shot up to 5000rpms, his CCRM was making a really loud vibrating noise and my gas guage shot up to full. I hope I didn't ruin his CCRM or mine for that matter. They're not cheap.


Anyways, I think I am going to try pulling codes tomorrow and/or drop the tank. I think something electrical is fried instead of the pump just being bad. Also, I don't know of any fuse link in the wiring. But if there is, that would make complete since.

hmm, im not sure that you typed what you meant. i agree - it seems that the pump is not likely the issue, based upon the CCRM issues. so i would hold off on dropping the tank.

also, i tossed the fusible link info out there for others to post about (i know foxes have one off the starter solenoid, but you have piggyback solenoids and completely different wiring). it was an abstract idea as fodder for others to say yes or no to.

good luck with it.

 

[rio95]

Alright, I just ran two wires from my battery to the wiring that goes to the fuel pump and it actually turned on. Therefore the pump and wiring by the pump is fine. So it must not be getting power or enough power. But I have tried two different CCRM's, so now I don't know what to do. I read I could check the voltage to the CCRM by checking the voltage at the number 11 pin in the connector, but I can't find a diagram that tells me which one is 11.

Also, I have not been able to find any backup about there being a fuse link anywhere???




This really sucks!

 

[HISSIN50]

I read I could check the voltage to the CCRM by checking the voltage at the number 11 pin in the connector, but I can't find a diagram that tells me which one is 11.

Loudtoy posted this in a thread of mine - about 3/4 of the way down the page is the diagram for the CCRM.

good luck.
EDIT: forgot to post link.

 

[rio95]

I found out that there is an pin in the EEC test port that if grounded 12v will be supplied to the pump. I did this and it turns out that it does work. When I grounded this and truned the key on, the fuel pump came on. I even started my car and everything seemed fine. I also tested the voltage at the pump and it was 12v. So I guess this might narrow it down a little farther. I think the problem is before the CCRM. I tested the pin in the CCRM connector that corresponds to the fuel pump and I only got 0.1v. I'm guessing that this isn't enough. Testing this pin is supposed to verify that power is going through the 20amp fuse in the high current fuse box. I'm still trying to figure out if there is a EEC relay that might be bad or something. I'm definitely stuck now.

 

[rio95]

Here is some usefull info from another post:

It's in the CCRM. Here is some info from the Ford service manual about how the fuel pump operates:


* The electrical system has a fuel pump control relay controlled by the powertrain control module (PCM) (12A650) which provides power to the fuel pump through an inertia fuel shutoff switch (9341) which is normally closed.

* The electrical system provides power to the fuel pump through two relays: fuel pump and powertrain control module relays. The power relays are located in the powertrain control module relay (PCM relay) (12B577). The CCRM is serviced as a unit. Current path depends on operating conditions.

* Contacts of both relays are open when the ignition switch (11572) is in the OFF position.

* The powertrain control module power relay is energized, closing its contacts, when the ignition switch is first turned to the ON position.

* Power is provided to the fuel pump relay and to a timing device in the powertrain control module.

* The fuel pump runs through the contacts of the fuel pump relay.

* If the ignition switch is not turned to the START position, the timing device in the powertrain control module will open the ground Circuit 57 (after approximately one second).

* Opening the ground circuit de-energizes the fuel pump relay (opening its contacts) which, in turn, de-energizes the fuel pump. This circuitry provides for pre-pressurization of the fuel system.

* The powertrain control module operates the fuel pump relay when the ignition switch is turned to START position to provide fuel while cranking.

* After the engine starts and the ignition switch is returned to the ON position, power to the fuel pump is again supplied through the fuel pump relay.

* The powertrain control module senses engine speed and shuts off the fuel pump by opening the ground circuit to the fuel pump relay when the engine stops or is below 120 rpm.



So maybe my PCM or PCM realy is messed up. I haven't found out where this is yet though??

 

[Teknik]

I went through all the same trouble you have.
Finally I got sick of it, so I stripped back the wires on
pins 5 and 11 on the CCRM , connected them together
and then ran a third wire from that to a switched source on the car.
Fuel pump works and has never given me trouble since.

Good luck man.

 

[rio95]

I thought about doing something similar to that. This pretty much means that you bypassed the fuel pump relay right??? So when you turn the key to on I'm guessing that the fuel pump stays on rather than primeing for a few seconds. When you say that you ran that third wire to a switched source, are you saying that you added a switch that you have to turn on everytime you start your car or did you run it to something else that is activated when the key is turned to ON???

 

[Teknik]

Yes , the fuel pump stays on rather than priming, so don't sit with the
key in the on position when the car is not running for too long.
How I did it was I stripped back pins 5 and 11 on the CCRM.
Don't cut them , just put a short piece of wire between them
as a jumper wire. then from that wire, run another wire to a switched
power source on the car. I used one of the wires on the ignition coil.
You could also wire it through the high voltage fuse box, so you could
add a fuse to it, but I don't have the specifics on that.
So essentially yes, I bypassed the fuel pump relay.
Like I said , I had the same problem you did and tried everything you did
also. I even bought a new CCRM from ford and that still did not work.
I would love to find out exactly what happened and fix it correctly
one day but it works perfectly now and I have no weird fuel pressure
problems so why should I mess with it.

 

[rio95]

I'm not so sure doing that on my car would work, because when I check for voltage at pin 11 with the key ON, I'm only reading less than 0.1V. Thats why I think something is messed up before the CCRM connector. But what really makes no since, is if I'm not getting power to the CCRM, why do I read a voltage of around 8V at the pump when I have my key in the ON position. Also, if I really am getting 8V to the pump like it says, why isn't it turning on. Yet when I supply 12V to it, it works just fine. Another weird thing is that the 8V I read stays on as long as the key is in the ON position. It SHOULD only stay on for a few seconds to give power to prime the pump.

 

[Teknik]

Pin 11 is power for the fuel pump relay, not the fuel pump.
Also pin 11 shares power with pin 10 which powers the pcm relay.
If you traced pin 10 and 11 back to where they originate, you would
see that they are coming from the same power source.
It's possible the pin 11 wire is messed up somewhere along that line.
Also I don't believe 8V is enough to get the fuel pump pumping.
I believe that is for warming up purposes only. So yes you should
always have at least 8V to the pump but should jump to 12
for priming and while the car is running.
I really hope you get your car going. I went through all this on my car
and I remember how frustrating and expensive it got.
Just remember , pin 11 goes into the ccrm for the power to the relay
only. Pin 5 goes out of the ccrm to the fuel pump itself.
the power that is being distributed to everything that the ccrm
controls comes in via pin 16 and I believe 18 has something to do
with the fuel pump also.
I tried so many things to get mine going and bypassing the
relay was all that worked. If you don't need your car right away
then keep trying things until you find what went wrong and fix it there.
I was moving to florida in 4 days when this happened to me so time
was not my friend at that moment.
I really hope all goes well for you. I might have some pics if you
need me to email them to you.

 

[rio95]

Thank You for the info.

I had another thought though. I read that there will always be a hot side in the circuit and that the way the circuit works is by the computer and EEC relay supplying a ground when needed. Therefore, you could read a voltage in all the right places, but if the circuit is not completed with the ground, then it wouldn't work. Therefore, maybe something is wrong with the circuit and/or EEC relay. I think this, because I am reading a constant 8V at the pump when the key is ON, so maybe the relays are just supposed to connect a ground to complete the circuit just long enough for it to prime, then it gets ungrounded. Then this whole time, there would still be 8V present.

I think I might try to ground the ground wire to the pump to something and then turn the key to on and see if that 8V just needed a complete circuit to activate the pump.

I also read that when you ground the fuel pump pin in the EEC test port and it turns the pump on when the key is ON, then the fuel pump relay and the inertia switch are both working properly. So maybe nothing is wrong with either on these, b/c when i ground that pin, I get 12V to the pump and it works.