97 Mercury Grand Marquis doesn't start on occasion after apparent fuel tank shut off

This is my 82 year old Dad’s car, and I’m doing this for him hoping that one of you fine people could help him.
He took it to the garage twice in the past six weeks to resolve the problem. The first time, Bill the mechanic said that he thinks it is a bad sensor, and he replaced the sensor, but at that time, it didn’t start when the engine was cold. Then immediately after taking it to the garage, the car began to not start every once in a while (in the middle of a trip) when the engine was still hot. And so, my Dad took it back to the garage and Billy replaced the fuel tank shut-off/reset button device in the trunk near the driver side hinge. But guess what, the problem still continues. And my poor Dad with his swollen legs from arthritis, a big lump on the side of his neck, and a urine bag attached to him doesn’t want to continue to have to return the car to the garage until Billy stumbles upon the right solution. I happen to be a conspiracy theorist, and so, I believe that Bill the mechanic intentionally placed a defective fuel tank reset button in my Dad’s car so that the garage could continually milk my old man for more money. I am really hoping there is someone out there who is familiar with the problem and will be able to diffuse my cynicism and offer a pain free solution to my Dad’s car problem. Thanks in advance.

There’s not enough info known to even hazard a guess but the fuel pump switch you’re referring to (it’s actually called an inertia switch) seldom fail and it’s a real shot in the dark to replace one of those.

Answers to some questions may help.
Any Check Engine Light on at any time?
Car been scanned and any codes present?
By not starting do you mean the engine will crank over but start up or do you mean the starter motor will not physically crank the engine over? (Vast difference.)
Does the engine die at idle or at road speeds?

If the car has not been scanned you might consider having this done at a local chain type auto parts house (AutoZone, etc). They will do this for you free. Post any codes back and do NOT expect the counter help there to diagnose the problem. That is not their job and there is far more to a diagnosis than a code number.

You really need to drop the conspiracy theory though. The odds of the mechanic placing a defective switch in the car to bleed your dad for money are close to zero.
The odds of this being a misguided diagnosis are much, much higher.

I thought I was pretty thorough. I would have mentioned all of those things you were asking about if they happened. And by it won’t start, I meant it turns over but no smell of gas, and so it has something to to do with the fuel shut-off mechanism –
whether that be the inertia switch or some other mechanism. If you could please call Bill the mechanic, or Chuck the owner, at Rhein & Sons Sunoco in Fairless Hills and tell him that replacing the inertia switch was a shot in the dark, I would appreciate it.

And since they said it was a sensor not working the first time my Dad brought it in, I am making the assumption that they spotted that with an auto scanner and therefore
are in the habit of using a scanner to find problems.

Has a fuel pressure test been done? It might be the fuel pump, and not the cut-off switch.

Try this: Turn the key on, but don’t start it. Listen for the fuel pump. It should run for a few seconds and then shut off. You can repeat this process as often as necessary to ensure you can hear it, but you need to leave about 10-12 seconds between attempts or it won’t run.

If you can’t hear it at all, then the pump isn’t running. It could just be getting weak, too. There could also a bad pressure control valve (no, that’s not right…what am I trying to say, guys?).

I doubt anyone here will call your mechanic. Sorry. Better luck, next forum.

No, the original post was not thorough at all and there was still no answer even to most of the followup questions I asked.
Wild guessing then I would agree with the bad fuel pump theory.

No, I’m not calling anyone. That’s bad form at best and is a real slippery slope to even approach.

Honestly, I haven’t seen anything in the thread so far that would suggest a fuel delivery problem as being more likely than an ignition problem. It’s possible that Billy might just have been wildly guessing. Without knowing what he looked, at, it’s impossible to tell.

90Astrovan, you may just want to try another shop. When faith is lost in a particular mechanic that’s really the best approach.

Has the fuel pump been replaced? Not sure why they replaced the inertia switch? Some fuel pumps fail completely and others fail “intermittently” and it seems this could be a case of the latter.

Thanks to everyone. I think most of you guys who think it’s the fuel pump is probably right. [the same mountainbike guy probably didn’t read the part about
not being able to smell the gas after cranking it over a few times.] But the fact that there seems to be a consensus on here that it is not the fuel tank reset button (enertia switch) is interesting. That job cost my Dad $336.

I am not sure if they did a fuel pressure test, but if the fuel pump is failing intermittently, then I guess it could pass the pressure test, right? I drive my Dad’s car occasionally, but it always performed well for me. If it happens to my Dad one more time, then I will give the mechanic a call and find out for myself. This particular Sunoco garage is actually the best garage around town. There are only two other mechanics in the area that may be more knoweldgeable, but the one has an attitude problem and the other is a one-man operation and is really slow. But all of the garages around here are always backed up with a whole bunch of cars in the lot, and we can’t afford the dealer, and so, I guess we’re stuck with what happens.

oops. I just talked to my elderly Dad again, and he said that I misunderstood him. It wasn’t that button in the trunk that was replaced, it was some fuel sensor that the mechanic replaced. He did it once the first time, and after my Dad returned the vehicle again, he told him that he put another one on free of charge. (Are these fuel sensor things that sensitive?) And it was that fuel sensor device thing, whatever it was, that costed $336.

It is good to know that you think that it’s not the fuel reset button in the trunk. I wonder if there is a good solid way to find out if your fuel pump is beginning to intermittently falter causing an occasional non-start (with engine cranking over a few times but with no fuel smell.)

Really no way to test an intermittent failing fuel pump. At some point is just stops working period and then the mystery is over. There are lots of sensors, connectors, and components involved with getting the fuel into the cylinders in a fuel injected car. Unfortunately, when something is amiss is can be frustrating to track down the root cause of the problem. It seems the local garage is doing the best they can, but I still suspect the fuel pump as part or all of the problem.

When the car won’t start can you hear the fuel pump make a humming noise that lasts about 2 seconds when turning the ignition switch to the on position? If not it’s likely the fuel pump, fuel pump relay or bad inertia switch. I had an intermittent starting problem on my '88 Ford Escort several years ago, but the only time the car wouldn’t start was when the outdoor temperature was cool/cold. The problem turned out to be the inertia switch. I bought and installed another one I got at a junk yard for $5. and haven’t had a problem since. A bad ignition switch is also a possibility that hasn’t been brought up.

FordMan59 and to any other person thinking it may not be fuel related:
NO SMELL OF GAS (how many times do I need to say it) when cranking over the engine a few times when it didn’t start. As for that humming noise the fuel pump should make when it doesn’t start, my parents were in the car at the time, but their hearing is going bad, and so, I am not even going to ask them.

And if it is the fuel pump, then I think my Dad will have to unload it before it goes all together because I know he is not going to pay $700 to put a new one in. It only happened three times anyway, about two or three weeks apart. Maybe he should drive it until it just goes; they only drive local anyway, and he’s got AAA.

OK, since no one else has said it, “NO SMELL OF GAS” implies a fuel delivery problem.

There isn’t any, hence no smell. We’re trying to HELP you here…read more carefully.

Why don’t you trade vehicles with them for a while, and see if YOU can find the problem? If they have hearing issues, YOU may be the one who can find and fix (get it fixed) for them.

“NO SMELL OF GAS” just indicates the engine isn’t flooded. One of my cars often takes a few tries before it starts, but I don’t smell gas unless the engine is flooded. As for $700. to replace the fuel pump, that sounds a bid high to me. The fuel pump can be changed without having to replace the fuel gauge sending unit although some garages would probably replace the complete unit. Most if not all Ford vehicles of that era have a place under the back seat where the fuel pump can easily be accessed and changed. I could possibly see $700. if it were like some cars once were where you had to take the gas tank out to get to the fuel pump, but this isn’t the case on most cars today.

Let me try and iron some of this confusing language out, first of all.
"but at that time, it didn’t start when the engine was cold. Then immediately after taking it to the garage, the car began to not start every once in a while (in the middle of a trip) when the engine was still hot."
No start, cold. Then after first repair attempt, intermittent no start (STILL hot? i guess ya mean “cold AND hot”)

What sensor is being bad? Because with this kind of information, or lack thereof, “Bill the Mechanic” knows way more about this car than any of us. But I could hazard a guess. No, guessing only would land me at a local chain type auto parts house (AutoZone, etc). Throwing parts at a car only works if you have money to burn. And by your tagline, unh-uh.

Bashing your mechanic (ex-mechanic?) will get you nowhere, especially if your talking to mechanic types.
Get some details, give us some facts. Let’s figure this no start out.

Did you say Fairless Hills? That is CrAZy, dude! I know where Fairless Hills is. I may even know where that shop is! Small internet.


PistolPT, are you aware that this thread goes back to October 2011?

“NO SMELL OF GAS”…Almost meaningless with todays fuel injected cars…You are never going to smell gas unless a fuel line breaks or is leaking…

If the car starts and runs normally when it’s in the mechanics hands, then there is little he can do to fix it without resorting to pure guesswork…it’s not getting any spark or it’s not getting any fuel, one or the other. If the problem can be duplicated in the shop, it can diagnosed and repaired in short order…or you can allow your mechanic to start throwing some expensive parts at it and hope for success…

Here is something maybe your Dad can do…Show him how to open the air-filter box. Next time it won’t start, shoot some starting fluid into the air-filter. If that produces a response, then the problem is fuel-delivery related…If the starting fluid does NOTHING, then it’s some sort of ignition failure…

Caddyman, I think the OP (from Oct 2011) is long gone. This is a very old thread. Time to let it RIP.

I HATE IT when that happens…PistolPT somehow dredged this dead thread up…