89 Crn Vic - Stalls on cold starts
 

1989 Ford Crown Victoria,LX, 302, AC, PS, PB, P/Win, F/Injected, The Works.

All has been well since (I think this past August) patching the vacuum line that knocked off the Climate Control, but Last week, its initial start of the day was normal as if new. The second start of the day, no foot on gas pedal, simply turn the key as always. The vehicle started normal and ran at its usual warmed up idle BUT then the idle dropped and the engine stalled as if running out of gas... not an instant shut down as if turning the key off.

Thinking "failed f/pump relay" as has happened in the past, I installed a new one (made in China) from Advance Auto (renamed from Discount Auto). Result = No Improvement. Thinking a flawed "new" relay, I had Advance Auto replace it with another = Still No Improvement. The engine starts immediately, runs normal for a very short time, then apparently runs out of gas.

There are two relays attached to the drivers side fender apron... according to the graphic I have, the forward relay, closest to the headlight as the Fuel Pump Relay. Is this correct?

If I play with the gas pedal, I can keep the engine running after a fashion so to speak but (this may be my imagination but it does deserve a mention) it does seem to run slightly rough and has an accompanying rough idle. After getting it warmed up, if I shut it down, then restart normally, the idle seem normal (smooth) and the slightly rough running feeling is gone.

When having my neighbor turning the key from the OFF position to the ON position (engine NOT running), and I'm listening at the engine compartment, I can hear the Fuel Pump Relay clicking in BUT I do not hear the fuel pump running those few normal seconds.

I also do not hear the fuel pump running when grounding out the short end of the DLC (hot-wiring to test the fuel pump)... BUT... when doing this test I can hear the internal fuel pump within the fuel tank running.

The fuel pump relay clicks in on the above test... however... is this test bypassing the relay OR simply have the voltage forced through the relay? (Still wondering about a 2nd new but faulty relay).

In assuming that the electric fuel pump has failed, and if so... any safety hints I should know, removal tips, its location?
https://cimg0.ibsrv.net/gimg/www.for...6b8fa9e3b8.jpg
1989 Ford Crown Victoria LX ...Something Worth Keeping

Good Morning Mr. Reeves.
Nice car, hopefully we can help some.
When you ground the test terminal in the DLC it grounds the coil for the fuel pump relay causing it to energize and close the contacts thereby sending power to the fuel pump.

Those long winded explanations !!!
If you hear the fuel pump run , that means it's running but we don't know how well. A fuel pressure gauge connected to the fuel rail is a better way to verify operation.
If you are contemplating replacing the fuel pump module, in the tank, It requires that pressure be released from the fuel system and the tank dropped down to gain access to the fuel pump. I don't think you would want to get involved with this job especially if the tank has a quantity of fuel in it and it can get pretty heavy AND dangerous.

Something I believe you would consider trying and that is to use a test lite as a visual indicator to confirm if the fuel pump relay is dropping out .Just use a few wires to connect the test lite to the output of the relay and ground. When you turn on the key the ECM provides the ground for the relay to close and an RPM signal takes over after the usual 2 seconds and holds the relay closed If the relay opens THEN the engine shuts down you have a picture of relay operation. Since the engine runs fine after warm-up we could be looking at something else. Another point to do the check is at the inertia switch which I believe in your vehicle is located in the trunk, ck owner's manual. Power comes from the relay to the inertia switch then on down to the fuel pump.
When the engine stops running it will lose the RPM signal and you need to be observant as to which occurs first ,engine stall then relay drops or relay drops then engine stalls. It has been a while since I worked on those and I have to go back into my archives to recall the info if I'm lucky !

Hi Hanky... Glad to see that you're still around and active. I did think to check the inertia switch in the trunk to see if I might have tripped it... every once in awhile I sort of hit the concrete posts in the disabled parking spots and from experience I know that's enough to trip that switch at times. I will definitely check the voltage to the pump at that point.

The pump inside the fuel tank is working okay... no need to be removing the tank.

SIDE NOTE STORY: I did rebuild the rear tank on my F150 years ago and replaced the 19 gal side tank. In removing the old side tank, I was sure it was empty. The last restraining bolt removed, the tank was stuck, laying on my back under there, I kicked it. It came crashing down and it wasn't empty after all... about 15 gallons of old gas... one spark and I'd have been toast! It became a Don Adams scenario via "Get Smart"... Missed Me By That Much! Yeah, I got a real education in the fuel tank removal area.

I'll now do a voltage check to the pump as you suggest, and since the external fuel pump isn't running, If I have voltage to the pump, I'll install a new pump, then report back. I appreciate the info Hanky.

Hanky, to make sure we're on the same page (my mind at age 86 has got a little thick), in checking voltage at the inertia switch in the trunk..... Normally 12v would be "constantly" present at both wires of the switch when the key is simply turned to the ON position?...........

Or just for that second or two when normally (if all was well) the pump would be heard running, then not? Sorry for the confusion.

BTW... "Joe" suits me just fine... that Mr Reeves thing is just for old people! :)

Joe, if I'm not mistaken,,,,,,,,,,,,,,,
there is only one high pressure fuel pump in the tank on the crown vic.
I realize you are quite familiar with the Fand E series which did have 2 pumps.

It might be a good idea to check out the Air Bypass Valve (solenoid) on the throttle body. Sometimes they get carboned up and don't work correctly.
Certain ones can be cleaned and others will require replacement because cleaning them removes the protective coating.

I just saw your last post,
The only time "constant" voltage should be present at the inertia sw is when the engine is running.
The computer provides the ground for the fuel pump relay for 2 seconds when the key is first turned on. If no RPM signal is received when cranking or running the relay will drop out cutting off the power to the inertia sw and fuel pump.