Fuel pump testing?

[doclees]

Here we go again. The wife's 93 atx is at it again. No start. Cranks fine. Just did the upper 60k a few weeks ago because of the same no start. At that time pressing the fuel pressure relief valve gave me a squirt of gas. Nothing this time. Not even a bubble. Just got back from CT and had no problems. I turn the key on and no pump sound. I never remember any significant pump sound before. My 89 is more noticeable.
So how do I confirm a bad fuel pump. I have a new old stock ready but don't want to change a good part out.
Tried WOT with no change.

 

[SHOZ123]

Connect a fuel pressure gauge to the fuel rail.

 

[shoclown]

could also be a relay... if pump does not pump check for power at pump before replacing it. make sure power and ground are there. dont forget about fuses, relays etc

 

[doclees]

Thanks folks. I can push down on the fuel pressure relief valve and get nothing. Not sure how connecting a fuel pressure gauge would give me more info.

Do I need to cut the back seat panel to troubleshoot the fuel pump?

 

[SHOZ123]

Maybe the roll over switch is bad in the trunk?

Hook up a fuel pressure gauge and turn on the key, should build up at least 30 lbs.

You can also command the fuel pump on 100% by grounding a pin at the data connector with the key on.

 

[1993BlackSHO]

Might be worth a quick check to make sure the fuel pump circuit breaker in the trunk does not need to be reset.

 

[SHOZ123]

Not a circuit breaker. It's a roll over switch activated by physical shock.

 

[doclees]

Maybe the roll over switch is bad in the trunk?

Hook up a fuel pressure gauge and turn on the key, should build up at least 30 lbs.

You can also command the fuel pump on 100% by grounding a pin at the data connector with the key on.

Thanks that is what I need to know. Do you know what pin?

 

[SHOZ123]

 

['94SHO]

Or pull the vacum hose off of the Fuel press. reg., and plug the manifold ******.
This commands the pump to run full pressure.(should be around 40psi).
Umm, you did check all pertinent fuses/wires? Got a circuit tester?

 

[shoclown]

the inertia switch may be cycled. reset the button on top (it is located in the trunk)

does the relay click when key is cycled?

 

[doclees]

Thanks folks. I am going to play with it tonight. That looks like the diagram I have in my Chiltons for all Taurus up to 92. SHOZ123 will that force the fuel pump on regardless of the inertial switch?
Not sure about the relay clicking or what I hear. I turn the key, do not hear the distinctive pump sound like I hear on my 89, but after a moment I hear a slight click from I think under/in the dash.
Anyone have a fuel filter get so clogged to give you no fuel pressure?
I always understood that when a pump goes bad it makes a lot of noise first. Can it just die a silent death?
Haven't checked other fuses but everything else works fine. I love my digital Ohm meter! Should have gotten one years ago.

 

[doclees]

OK inertial switch not tripped. Pulled codes - 176 Oxygen sensor not switching - system is or was lean Left or Front HO22SSS - Fuel control
543 O) Fuel pump monitor circuit shows no power - Power / Fuel Pump Circuits
(M) (Service 556 code first if present) Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits
Does this narrow the troubleshooting?

The good new!! no more EGR codes.

OK checked the fuse block under hood behind left strut. All good. Jumped fuel pump as above- no sound from pump. Is it surgery time?

 

[SHOZ123]

Or pull the vacum hose off of the Fuel press. reg., and plug the manifold ******.
This commands the pump to run full pressure.(should be around 40psi).

It doesn't command the pump to do anything. It only removes the hardware limit to the fuel pressure regulator.

The FPR should be ~40 lbs at no vacuum (WOT), 35 lbs at normal vacuum (15" HG) or ~30 lbs at high vacuum (20" Hg) such as a high rpm coast down.

 

[doclees]

So given the troubleshooting done so far, is it reasonable to cut open the seat floor at this time?

 

[naval-avi8or]

So given the troubleshooting done so far, is it reasonable to cut open the seat floor at this time?

NO!!

Make sure your CCRM is powered and that the fuel pump relays are sending power to the pump. Is there power at the Inertia switch when you have the pump test connector grounded.

 

[doclees]

Ok I assume I just need to run a volt meter between the connectors on the inertia switch to test power there. Here is where my knowledge runs thin. What/where is the CCRM, what fuel pump relays and where, and how to test.
You know even my 79 honda cb650 manual has a troubleshooting flow chart. One would think the ford manual would also.

OK found the CCRM but don't know how to test. Checked volts at inertial switch - 9.5. Switch seems to work. Shake it and it trips. I'll search more for CCRM testing until someone reads this.

found this http://www.shoforum.com/showthread.php?t=14719&highlight=CCRM+testing. If anyone finds error in this older thread please let me know.

 

[doclees]

My fuel pump works great. The CCRM doesn't though. I ordered one through Autozone. Anybody know of a safe bypass until my new one comes in?
thanks

 

[naval-avi8or]

NO the only SAFE way is to replace the CCRM. There have been guys that have wired the pump up thru a switch mounted in the interior of the car but once again that is not SAFE. The CCRM is driven via the PCM and shuts the pump off under certain conditions, a remote switch will NOT and creates a very high potential for fire in the event that the inertia switch isn't triggered.

 

[doclees]

http://www.shoforum.com/showthread.php?t=74962&highlight=ccrm+bypass

Then you don't feel the above link shows an option that is safe? I was getting the idea that this would replace the CCRM's internal relay with an external relay but function or be triggered the same.