My Ride: 1999 Mercury Grand Marquis...43,000 miles.

Has run wonderfully for 10 years. Only problem was an Idle Air Control Valve, which I replaced a few months ago.

I have a very frustrating INTERMITTENT problem.

Problem: Car runs great once started. Sometimes when I stop, when car is warm, it will not start. Have been towed home twice.

Symptoms: Car will crank just fine. No fire. Occasionally it will stumble a little the first couple of tries, but that is all. When it is going to start I hear the fuel pump run for a couple of seconds when I turn the ignition ON. Then it starts OK. When it will not start there is no fuel pump noise when the ignition switch is turned to start. If there is fuel pump noise it usually starts.

So, I suspect the fuel system. Have checked all relays and fuses. They are good. I have also checked all voltages. The Fuel pump relay is sending a signal to the rear of the car. I have read the Trouble Codes...No Codes.

I have also used the 'fuel pump primer' connector to send power to the back of the car. If the pump is 'working' I hear a click in the pump. When not working I hear nothing. One last thing...I have also checked the inertia switch in the trunk and it is OK.

Now, here is how I get the sucker to run when it is 'down'. I crawl under the car and tap the fuel pump housing with a hammer (a metal hammer works but a plastic one does not!). Once I do this it usually will start.

So, my conclusion, so far, is that the fuel pump is 'bad'. It seems to be stopping sometimes in a position that does not allow it to start without the jarring that the hammer supplies.

I have a couple questions:

1. Is it likely the fuel pump is bad or could there be something I missed?

2. I ran across a Ford Service bulletin (98-26-2) that says:

This TSB article is being republished in its entirety to expand vehicle model coverage and revise the text.


Some vehicles using winter blend fuels may exhibit a stall on start up and a no restart, hard start condition or a no start condition in unseasonably hot weather (greater than 27C/80F). These concerns may be related to fuel volatility from winter blend fuels during winter-spring and autumn-winter transitions and may result in a fuel pump vapor lock condition. This condition may appear to be a fuel pump failure but may be caused by winter blend fuel.

The first sentance certainly describes my situation. We are at the winter-spring transition and it is well over 80 degrees here in Ft Lauderdale. Could this 'vapor lock' problem Ford describes cause the pump not to run until jostled (with my metal hammer)?

3. If, indeed, I have to change the fuel pump:

A. What is the best brand to buy?

B. Can the fuel pump be changed in a '99 without dropping the fuel tank?

Any help would be appreciated....



My RedSled (NO computers, fuel injection, emissions crap, Lighting Control Module, TCC, NO problems...)