Need help diagnosing my 2001 Mustang Bulllitt GT

bwcobra15 · #1 (**permalink**) 12-20-2011, 10:12 PM

stats: bought new in April 2001 - #621. Faithfully maintained at recommended intervals at Doug Stanley Ford. Now at 186,000 miles

only updgrades are : TriAx shifter
: Densecharger cold air instake (OEM intake is back on now)
: fr 17x9 w/Nitto 275s, rear 17x10.5 w/Nitto 315s

Now the engine stalls and hesitates, usually when moisture is in the atmosphere and ground. The first time it occurred was a while ago after I pressure-cleaned the engine, and let it air dry. Then it would just run very rough, like not all cylinders were firing.

The latest incident was today, after driving 2 hours in drizzle to east Texas. Now upon hard acceleration it hiccups and stumbles. Now i'm wondering if its a fuel filter. I cant remember the last time that was changed.

The spark plugs has never been changed. I got a set of champions from Five Star Ford but haven't done it yet, after looking at having to remove the COPs, throttle body, half the intake manifold to get to them, etc.

jhv48 · #2 (**permalink**) 12-20-2011, 10:16 PM

186,000 miles and still has the original plugs?

I don't call that properly maintained.

Replace them and test again.

bwcobra15 · #3 (**permalink**) 12-20-2011, 10:25 PM

Quote:

Originally Posted by jhv48

186,000 miles and still has the original plugs?

I don't call that properly maintained.

Replace them and test again.

Ok i'll give that one. Oil and fluids were routineelly change. doesnt burn or smoke at all.

Busabob · #4 (**permalink**) 12-21-2011, 05:12 AM

Make sure you do the spark plug boots when you do the plugs, they're both due at 100k.

cobrarkc · #5 (**permalink**) 12-21-2011, 07:30 AM

I would change the coils when you do the plugs and check for any leaks around the scoop could be dripping on one of the coils and misfiring, happened to my son's 2000 Roush.

bwcobra15 · #6 (**permalink**) 12-21-2011, 08:40 AM

Quote:

Originally Posted by cobrarkc

I would change the coils when you do the plugs and check for any leaks around the scoop could be dripping on one of the coils and misfiring, happened to my son's 2000 Roush.

Thanks for the advice -- I'll change the plugs and boots and hope that helps.

Also, I've never liked that fake air scoop. It serves no purpose other than catch water when its washed and streaking the hood no matter how well you dry it. Maybe when I get the car repainted I'll have it removed, and fabricate something that looks more like the original '68 GT.

Mark IV · #7 (**permalink**) 12-21-2011, 08:57 AM

Pray that at 186,000 the plugs will come out! I never let plugs go more than 50,000 on the daily drivers despite them being "good" for 100K. I have seen more than a few busted plugs or stripped aluminum heads from plugs that had welded themselves into the alloy heads.

And use some never-sieze on the new ones despite the "anti-sieze" allegedly on the new plugs.

mreid · #8 (**permalink**) 12-21-2011, 09:32 AM

I also hope to hell you get the plugs out. The factory applied lube is little more than oil and after 10 years and over 7,000 heat cycles is long gone. If they don't budge, you may need to run the engine to temp and try to take them out hot. Even that may be difficult. Good luck!

bwcobra15 · #9 (**permalink**) 12-21-2011, 09:41 AM

Quote:

Originally Posted by mreid

I also hope to hell you get the plugs out. The factory applied lube is little more than oil and after 10 years and over 7,000 heat cycles is long gone. If they don't budge, you may need to run the engine to temp and try to take them out hot. Even that may be difficult. Good luck!

I'm going to have a Ford Master Mechanic do it at the dealership. He assures me he's done the job many, many times. Thanks.

cobrarkc · #10 (**permalink**) 12-21-2011, 10:08 AM

I had two friends take their Ford Expeditions to Ford Master mechanics and both ended up with broken plugs that cost them an extra $200 to get them extacted. Try soaking them with WD-40 for a couple days before

Grubby · #11 (**permalink**) 12-21-2011, 06:05 PM

I also pull plugs and reinstall with anti-seize at about 50k. You risk them being stuck if you don't.

John

Joe Wicked · #12 (**permalink**) 12-29-2011, 05:11 AM

I had an 03 and I had problems with the stock air intake as well. When it was wet it wouldn't run quite as well. By removing the rubber boot from the fender well that goes to the the Airbox, it ran much better. I also changed the plugs early. I tended to do it at 30K just to prevent any issues. Do make sure they put anti seize on at the dealership. Most times they do not, they do the same as Ford did originally.