1995 Mercury Grand Marquis - Crank/No Start

[friskyfrankie]

I have a friend that has the above mentioned car too distant for me to currently check out in person. Out of nowhere, he developed a "crank - no start" situation. He said the battery tests out at 12.63 V with sufficient amperage. The terminals are clean and tight. It has a full tank of gas. I suggested spraying a snort of starter fluid, in the TB, to see if it starts, even for a few seconds to see if it is a fuel issue. Depending upon those result, we can look elsewhere, if needed. Could be a fuel pump, relay or fuse. Also possible are crank and cam sensors. Are there other more viable possibilities I haven't mentioned? All thoughts are welcome!

[sly]

check the inertia switch in the trunk (fuel pump cutoff). Maybe try whacking the rear quarter to trip it and then reset it just to check. Is there fuel pump noise at key on? Clogged fuel filter can also do this.

[friskyfrankie]

check the inertia switch in the trunk (fuel pump cutoff). Maybe try whacking the rear quarter to trip it and then reset it just to check. Is there fuel pump noise at key on? Clogged fuel filter can also do this.

I'll pass all of this along. Wonder if you can pull the connector, on the inertia switch and jump the terminals. Should produce the same test - right? I asked about the fuel filter and the car was running great when last used (a few weeks ago). The filter has less than 3k miles on it. Not sure if he hears any fuel pump noise when turning the key.

Just as an aside, I asked him if the button was down or up on the inertia switch and it is completely down.

[sly]

Yes, jumping the terminal on the connector to the inertia switch will verify if the switch has gone bad if resetting it doesn't work.

As an aside... that's pretty much the way I've had fuel pumps die on me. Works fine one run and next run won't work at all.

[friskyfrankie]

Get the funny feeling the inertia switch is fine and the issue is elsewhere. Guess time will tell but I'd accept any other thoughts not yet mentioned.

[massacre]

If the inertia switch is tripped, the fuel pump usually won't prime when turning the key. Can also check shrader valve to check pressure

[friskyfrankie]

If the inertia switch is tripped, the fuel pump usually won't prime when turning the key. Can also check shrader valve to check pressure

From what I understand, the inertia switch is down so the easy fix may not apply here. Since I can not do it personally, I'll need to pass along any thoughts to check it out. Fuses and a quick snort of starter fluid in the TB should start to eliminate matters.

[gadget73]

a honk of something flammable in the throttle body will tell you if its fuel or fire. If that doesn't make it go, have a gander at the crank position sensor. if that dies or just gets crusty enough you get no spark and of course no run.

[friskyfrankie]

a honk of something flammable in the throttle body will tell you if its fuel or fire. If that doesn't make it go, have a gander at the crank position sensor. if that dies or just gets crusty enough you get no spark and of course no run.

That's the plan but doing it remotely is a challenge as I am depending on another person. Hopefully, we don't lose anything in the "translation"!

[friskyfrankie]

Had my friend follow (at least I hope) my instructions to diagnose the issue. Gas tank is full. He checked all fuses for continuity and they were fine. Swapped the fuel pump relay with another and even tried jumping the connector without the relay and still no joy. Then squirted a little starter fluid and it started until it ran out. Got to figure either bad wiring at or near the fuel pump or the pump itself is shot. Am I missing anything? .

[sly]

Sounds like the fuel pump died. Did that on my wife's 2000 CV. 3/4 tank and no joy. Had to pump out the tank through the pressure port. That was a PITA.

As long as we are sure there is voltage getting to the pump harness, yeah... bad pump or clogged sock.

[friskyfrankie]

Sounds like the fuel pump died. Did that on my wife's 2000 CV. 3/4 tank and no joy. Had to pump out the tank through the pressure port. That was a PITA.

As long as we are sure there is voltage getting to the pump harness, yeah... bad pump or clogged sock.

That's why I want him to verify all the wiring is good since nobody wants the expense and work of replacing a fuel pump unnecessarily! I understand he may have to go in for a brief hospital stay so this may take a while. Trying to help diagnose this from afar which we all know is not easy! Don't think he has to drop the tank - maybe remove the real passenger wheel and move the exhaust pipe aside (he has dual exhaust) and "maybe" he can get to it? I know on the later CV's and GM's you can do that but on a '95? Still would like to know the inertia switch is not an issue. Got to have him trip it and reset it just for my own piece of mind!

[sly]

Backprobing the inertia switch is the easiest way. Just poke the negative lead on a bare screw head (preferably one of the grounds bolted in the trunk) and make sure there's 12V on both leads with the fuel pump relay jumped. No need to even turn the car on.

[friskyfrankie]

He checked the inertia switch today - got 12V on both leads. Gave it a slight tap to "activate it" and pressed it back down (a few times). Also jumped the connector - No joy in Mudsville! Looking more like a wiring issue, possibly in the tank area or just a bad pump. Due to his conditions, this would probably take more time to shake out as his health is more important. I'll update this as information comes in.

[gadget73]

if you have power at both sides of the inertia switch, its either a ground, broken at the pump connector on the front of the tank, or most likely the pump itself. If the tank is full, its the pump, just because thats the most inconvenient time for a pump to fail.