Topic: 1999 Mustang GT

[tfenos]

Ford
model Mustang GT
year 1999
 I have a 99 Mustang GT with approx 66,000mi. At about 1800-2000 RPM's, in gear or out of gear. I get an engine stumble or vibration. Before I realized that it would do it without driving or being in gear i assumed it was a tire issue. Put new tires on, still there! After I realized it would do it sitting in my driveway, (not in gear) that ruled out the transmission.
Changed spark plugs thinking MAYBE... HELP ME I am frustrated... Otherwise the vibration/stumble seems to go away after 2500-3000 RPM's... Thanks for any suggestions in advance... -Frank

[ol dirty doug]

did you gap them properly?

[tfenos]

Gapped em at .54 .  the shake was there before

[ol dirty doug]

check engine light on???

[tfenos]

nope

[Soaring]

Check your fuel filter, and your fuel pressure.  Your tires and transmission have nothing to do with engine stumble.  Most likely you have a fuel issue. 

[tfenos]

Changed the fuel filter...  problem still exists..  TPS? maybe
Thanx in advance

[tfenos]

How can i tell if its a bad coil pack?

[ol dirty doug]

well if you take it off auto zone can test them for free.

[Soaring]

Each cylinder has its' own coil.  Take it into a Ford dealership and have them run the numbers.  Most likely you have at least one burned up coil. 

[tfenos]

Changed the throttle body and upper intake plenum this weekend, also changed the throttle positioning sensor.  Still there, although it seems to have lightened up.  I'll take it to FORD this week to have them check the Coil packs..  Thank you for all the input, its very appreciated. (Is there a way for me to check the coil packs myself, maybe a voltage check?)
-Frank

[Soaring]

No, you have run the numbers to see which coil i s bad.  Most likely #8

[tfenos]

OK...  Thanks..  Let you know what it is as soon as I find out...