Help a newbie

[keely111]

Hi,

My 99 Crown Vic has 129,000 on it and generally runs great.

I have had a sporadic problem with the car failing to maintain idle. I dumped a can of Heet in the tank and coincidence or not the problem stopped but, a month later has shown up again. I vary where I buy gas so I don't think it's water in the tank but....

I am going to start with simple first. I want to change the fuel filter but how do I get the filter cannister apart to replace the filter. Maybe I was missing the obvious but I didn't see an easy way to do this. This could well be the original filter and may be the source of my idle problem.

Also any brand type recomendations on spark plug wires and spark plugs? Any big trick to putting them in other than one at a time?

Remember I'm a newbie so please be clear.

Thanks,

[BMFer1]

Hi, Keely111.

First off, what do you mean exactly by failure to maintain idle? Rough idle, high idle speed, low or no idle speed, sporadic, or what? Be more specific and I can hopefully help you there.

There is no canister to take apart to change the fuel filter. All you need is a flathead screwdriver. The filter is located on the inside of the passenger side fuel rail beside the muffler. Remove both fuel lines by first sliding out the plastic clips with the screwdriver, then just pulling them off. Then, loosen the large hose clamp & slide the filter out the front of the housing. Installation is the reverse. Make sure to use a Motorcraft OEM filter for best results (Motorcraft #FG-800A, about $12.00). I doubt the fuel filter is causing an idle problem, but change it anyway if you don't have a clue how old it is.

1998 & later Crown Vic's do not have plugwires. There are 8 individual coils that sit directly on each plug. Use a 7mm socket to remove the coils to access the plugs (you may need a 7mm wrench on #7 plug if the OE bracket is still in the way.) USE MOTORCRAFT OEM double platinum plugs. Anything else will not last as long-trust me. When you install them, apply a SMALL amount of antisieze compound to prevent them from bonding to the aluminum heads. Make sure they are properly gapped (approximately .054 thousanths.)

Hope this helps

[keely111]

The car will simply die over and over again. I have to drive about 4 miles through city streets before I hit the highway and it dies at every stoplight. Once I hit the highway I have no problem. I have about a 1/2 hour ride on the highway till I get back to city streets right before I hit home and at that point it ceases to die and runs fine.

Do I need to replace the individual coils at this mileage or will doing just the plugs work as well?

Any other suggestions for maintenance at this point?

I've changed engine oil/filter every 4000 miles and trans fluid gets changed once a year or 20,000 miles ever since I bought the car in 2000.

Many thanks and happy holidays.

[BMFer1]

Ok, Keely111, is it idling smoothly when it does idle, is it skipping, any check engine light or codes? If all seems well, I would suspect the idle air control (IAC) valve, located on the back of the throttle body, is possibly sticky. One easy check on the IAC is to unplug the electrical connector from it at idle, and see if there is any change in idle speed. If no change, valve is sticking.

You do not need to change any of the coils unless one is not firing. They either work or they die.

On the maintenance, that all depends on maintenance history. If the rearend dope hasn't been changed yet, for example, time to do that. It's hard to suggest what maintenance procedures to perform without knowing the full maintenance history on the car.

[keely111]

How do I unstick an IAC? Degreaser or lubricant of some type?

You make a good point about the rear end. Time to do that I think as well as a radiator flush and refill.

Other than that it runs like a dream.

Many thanks,

[keely111]

It idles smoothly and very quietly.

[BMFer1]

Originally Posted by keely111

How do I unstick an IAC? Degreaser or lubricant of some type?

You'll rarely have any luck "unsticking" an IAC Valve. They are easy to replace, cost about 70.00 from Ford. Don't replace it though unless you check it out first.