2000 Grand Marquis Fuel Problem - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

chrisreed26 · 04-21-2011, 09:55

Hi I bought a 2000 Grand Marquis GS with only 44K miles owned by a senior citizen. It set for about a year after her death and her son put a new battery in and it started up fine. Few weeks later it would not start. $1100 later he had the fuel pump replaced, fuel filter changed, gas tank cleaned out and injectors cleaned out. after that I bought it for a steal at $2800.00. Drove it 300 miles on a tank of premium gas no problems filled up again and after about 20 miles on the interstate I hit 70 and it kinda bucked/surged and the check engine light flashed. I pulled off the road but it never did stall and was still running smooth. I drove home at about 50/55 20 miles and it was fine. What do you think the problem was? Do the injectors need to be cleaned again or did they not do a good enough job cleaning out the gas tank? Any advice I would hate to re-do all that was already done at the local Goodyear place. Thanks
Chris
2000 Grand Marquis GS 44K old person miles

NoLeaks2001 · 04-21-2011, 13:43

Hi,welcome to the board.
You did get a steal on that one,absolutey WAY too cheap!

But you have to watch some of these old people. Maybe after she was well past the church she put her foot into it and was going around corners with the rear end swung out.

If it was mine I'd take it into an AutoZone and get a free reading of the "check engine" code as that could steer you to the problem.
I would clean the MAF sensor as step one after checking that the air cleaner was nice and clean.

Steve83 · 04-21-2011, 14:07

First: stop putting hi-octane gas in it. It's not good for it, and is a BIG waste of $$$. Did you fill it in a different region from where you live? Did you fill it very close to the change of seasons? Either could result in you burning the wrong formula of gas. Read this caption:

Second: misfires & bucking in that car aren't necessarily related to fuel. It's often coils burning out, intake leaks, or even the residue of a repaired intake leak. Be careful with the spark plugs because they're also known to eject.

Third: I wouldn't clean the MAF, but if you feel you have to, use CRC brand MAF cleaner - nothing else. And follow the instructions on the can.

chrisreed26 · 04-21-2011, 18:11

Thanks for the advice. I have a code reader and did hook it up today but no codes stored. Guess the light did not stay on long enough.
I replaced the air filter and changed the oil when I bought it last week. I only used premium fuel since it had set a while. Trust me I will not be using it anymore!! Too much $$$$ Even my 2005 Infiniti QX56 calls for it and it does make a difference in that one but I still use the cheapest gas in her.
The Grand Marquis is a cheaper replacement for the QX56 so I hope to get many years of use out of the car. It drives like a dream except when it was bucking.....
So the MAF....I looked online at the auto parts store...thats not a cheap little part...it can be cleaned? How would I know it needed or if it was faulty?
If I had a fuel system problem would it only show up on hard acceleration? Because at idle and under 55 it's smooth. I have not tried to go past that speed again guess I probably should get it to do it again....
What out the TPS? I'm tempted to buy a new MAF just to be sure but since it's $175 new how can I test it? Can Autozone do that?
Thanks again!
Chris

**87_Crown_Vic** · 04-21-2011, 22:47

when was last time car had plus and stuff done??? i know the 5.0L Panthers bucked and acted like transmission problems sometimes from needing tune-up... makes me wonder how they cleaned injectors... did they remove or use stuff to flow thru lines to get to clean them... if they removed them, maybe an injector or 3 has bad seal/"O" rings on them and leaking out...

**Bert** · 04-22-2011, 11:39

It's probably a coil going out as Steve83 mentioned. You could replace them all and be done with it or you could replace one and see if it goes away. If not, use the one you took out to swicth with another position. Keep doing that until it quits the problem.

Steve83 · 04-23-2011, 21:16

Don't throw parts at it. The MAF can be tested, but it's not a likely cause anyway. You might buy 1 coil as Bert suggested since they WILL go out, and you're gonna need a few eventually. But DON'T buy the crap they sell in the zone. A MotorCraft coil from eBay or RockAuto is a few cents more, at most.

chrisreed26 · 04-25-2011, 15:41

Thanks for the ideas. With the low miles 44K would it be possible for the coil packs to be bad? I'll follow the test instructions for them. Thanks...
I have a gut feeling fuel issue since it set for a year but I guess I'm paranoid. I once bought a 1997 Fleetwood Bounder Motorhome with only 7K miles on it...a 10 year old rv with that low mileage...well one day on the interstate when I hit 1/4 tank it started backfiring, surging and would not go over 45mph..check engine light came on also..limped home and took the fuel filter off...full of rust!! It looked like clay! Packed full...changed it and it ran fine...sold it and guy called saying the same thing!! I bet he had to take the tanks out and clean them also...but the Grand Marquis has had all that done....I hope it's the coil pack! If it's fuel related it will be a ongoing problem I bet!

**Bert** · 04-25-2011, 17:02

I think you said you replaced the fuel filter. It might se a good idea to remove it and see what kind of flow it has. It's a cheap part to replace anyway.

chrisreed26 · 05-05-2011, 17:16

Update on my problem... I took it to a nearby shop and we went for a drive. He drove the car hard and floored it several times. It stalled several times...we barely made it back to the shop. They put a fuel pressure gauge on some port on the rail and put it in gear while braking and the pressure was maybe 15-20 psi when it should have been over 30. So they said the fuel pump Goodyear put in was faulty/weak. I did not want to take it back to Goodyear or have it towed or deal with going around and around with them so I told this shop to replace it. $450 later problem appears solved....funny their price with labor was less than just the part at Goodyear!!
Still need three window regulators. I only have one working power window....
A buddy said he would do all three for $100.00 labor.....any idea on what price is good for a regulator? The window motor itself does work...