87' G Marquis Won't Start

GORDON.M

MEMBER
1987 MERCURY MARQUIS

1987 Mercury Grand Marquis, 130k mi. 5.0

Hello and thanks for the great resource. A solution that works will merit a donation.

My Marquis had been sitting for about 3 weeks during a cold snap several weeks ago (Md.) And when I went to start it, it just tuned over. I replaced the bad battery which was 4 years old and suspected it was the TFI as I have had to replace that unit 3 times over the life of the vehichle which I bought in 88'.

I took the TFI to the auto parts store where I bought it for replacement if defective and the test came back ok on the unit and the guy said it could be either the mating unit in the distributor, the safety shutoff switch or I figure, the fuel pump. Is there a fuse for the fuel pump?

I know where and how to get to the fuel pump and test the line pressure, but I believe it's not running since I no longer "hear" it whining "running" when I turn the key to start, so I would like to start with the easier of the fixes before tackling the fuel pressure and tank if necessary, but am not sure where the switch is located or what it looks like?

There is something attached in the trunk near the driver side hinge that looks like a switch, but it appears to be depressed and fiddling with it has no effect on starting.

I've read the forum and will be doing the spark plug test for fire to the cylinders, but I need to locate that safety shutoff switch I've been reading and told about to test it for defectiveness. My Chilton's doesn't even mention it. :(

If that switch is it, great & thanks. If not, do you know where is it and is there anything else I should look at while troubleshootijng this out.

It's odd, the damned thing ran reliably, I parked it, it sait for 3 weeks during the freeze and now won't start.

Thanks for any help in solving this.

Regards,

G

3 Replies

MERLIN2021

MECHANIC
17,250 POSTS

First you need to figure out if the car has spark? Pull a plug wire off and put it neer a ground and crank the engine. You should see a blue spark. If no spark ckeck you coil. If you get spark the trouble is fuel related. The fuse and relay for the fuel pump are under the hood in the power distribution box, with you first turn the key to ON position you should hear the pump run for a few seconds. When checking spark don't hold the wire! Strong electrical voltage can injure or kill!

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Monday, March 5th, 2007 AT 3:33 AM

GORDON.M

MEMBER
2 POSTS

Hi,

Appreciate your response, but as you have read, I'm already on that and am aware of the relays. It's that safety switch I'm fuzzy on. I've used screwdrivers for years to check for fire and am a bit embarrassed that I never thought to use a plug which is boneheaded to say the least. :Oops: I need to verify where and what the fuel cutoff safety switch looks like and is located. I can't find any literature on that subject which seems dumb to me, but than I've always used a screwdriver to check for spark, so what do I know. :Roll:

Thanks again.

G

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Tuesday, March 6th, 2007 AT 1:40 AM

MERLIN2021

MECHANIC
17,250 POSTS

So the problem is no fuel? The ineria switch is usually in the trunck it's just a button make sure it's pushed down. The fuse and relay are under the hood usually near the radiator in the power distrbution box. But have you tried the coil?

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Tuesday, March 6th, 2007 AT 6:51 AM