HELP! Stang hesitating/missing...

[dz7b7h]

UPDATE: Hey guys... just now getting time to look into this again. Haven't had time to replace the fuel filter. Wanted to see if anybody else has any ideas. She started running fine a few days after I replaced the coils. I haven't been driving her much but I was going down the road the other day and out of nowhere the car jerked hard, the tach dropped to almost zero and then everything went to normal. She did this about 4 times and then the check engine light came back on. It flashes probably like 30 times then goes solid. Now once again she is idling rough and is very sluggish. Could I have a flaky O-sensor???

I've got a '97 GT Manual Vert w/ little mods up to this point. She's been running fine... Started it about 3 days ago and noticed that it took a long time to start. then it idled really rough. As I got her down the road the engine started hesitating/missing then the Check Engine light came on. After inspecting/testing sensors, I pulled the spark plugs and found 2 of them covered in oil. I'm guessing I have a seal problem??

Thanks in advance everyone.

D.C.
1997 Mustang GT Vert
3.73 Gears
K&N Filter and homemade RAM Air

 

[mdvaldosta]

Any of the 4.6 engines will work fine, a PI motor (99-04) is a direct swap. 4v motors will need some wiring work.

 

[ACSPONY]

Any of the 4.6 engines will work fine, a PI motor (99-04) is a direct swap. 4v motors will need some wiring work.

 

[dz7b7h]

Okay. Thanks. In the mean time... a buddy of mine suggested bad spark plugs or ignition coil may be my problem. I tested the ignition coils last night and they tested fine. Went ahead and replaced the plugs this morning. Now it is only hesitating during accel right around 2K rpm in 3rd, 4th and 5th. Any clues??? I've cleaned my air filter, tested the MAF.

 

[dz7b7h]

Update: Filled her up and dropped in some fuel injector cleaner (lucas?) Seemed to help things quite a bit. Now she is only hesitating about every other run. Could I have a fuel injector going out??

 

[Mike97gt]

Okay. Thanks. In the mean time... a buddy of mine suggested bad spark plugs or ignition coil may be my problem. I tested the ignition coils last night and they tested fine. Went ahead and replaced the plugs this morning. Now it is only hesitating during accel right around 2K rpm in 3rd, 4th and 5th. Any clues??? I've cleaned my air filter, tested the MAF.

i bet you have weak spark on one cyl. is it setting a misfire code now? if not identify what cylinder and then replace the plug wires and test that coil pack.

 

[dz7b7h]

I went ahead and replaced the ignition coils.. after inspecting them they had quite of bit of corrosion on the underside and on the power terminals. I guess I didn't think about the wire... they are really new like from Feb of this year. But I guess with enough heat (I do live in the Houston area) anything could happen.. I'll check them out. thanks...

 

[dz7b7h]

Wires are good... I guess i'm really down to fuel injection... maybe a bad fuel filter?? anyone?

 

[Kilgore Trout]

Never hurts to replace fuel filter

They are good for about 30k miles if you always get quality gas...