Slight miss,sputter at idle only

Lugen

Registered User
Hi,
This seemed to have been there for a while. Since the car is running almost like new I want to try and clear this up.
I have a Pro M 75 mm and BBK 70 MM BBK Tb with a ZR Motorsports Inlet tube 9 inch KN Filter.
What happens is if I'm in neutral OR Stopped at a light it will for a split sec sputter, or miss(?) happens once twice a min or every few min, no set pattern . RPMs are around 600 ish. Give it gas I'm fine drving too .Besides that all seems fine except for a creaking noise in my front end. :)
Any takers? No Codes!
Thanks
Lee
 
Last edited:
Have you had it dynoed? Do you have to get emissions tests?

How do the plugs look when you pull them.

I'm guessing maybe you're running rich at idle and every once and a while a plug fouls, causing that stutter or miss.
 
Lee,

My SC did that for years, I never did figure out why. With the cam that's in it now it lopes and shakes so bad at idle, it feels like it's running on 4 cylinders.

Usually problems with idle are MAF related.

David
 
Maybe re calibrate?

?? I added the BBK and Tube after I gotr the Pro M75
Maybe thats it?
 
Check Vaccum Line to Gas Tank

Lee,

I had a similar problem and it turned out to be a vaccum line located on passenger side of the engine near fire wall that connects to the fuel tank.

I started by pulling codes and got fuel pump problem. I drove it around for a few more days dreading replacing the fuel pump. One night as I parked in the garage, I heard a hissing sound when the engine shut off. I guess the leak finally got big enough to hear. Anyhow, I followed the sound and they used the Ford factory vaccum manual for my 94 5spd to identify the purpose of that line. When it said it was related to the fuel pump, I was dumfounded. I replaced the line, cleared the codes and no similar problem since.

Don't know if that's your trouble but can't hurt to look. Definitely pull the codes though.

Good luck.
 
Re: Check Vaccum Line to Gas Tank

mduralia said:
One night as I parked in the garage, I heard a hissing sound when the engine shut off. I guess the leak finally got big enough to hear. Anyhow, I followed the sound and they used the Ford factory vaccum manual for my 94 5spd to identify the purpose of that line. When it said it was related to the fuel pump, I was dumfounded. I replaced the line, cleared the codes and no similar problem since.

Don't know if that's your trouble but can't hurt to look. Definitely pull the codes though.

Good luck.

Hey Mike did the idle kind of fall off just every once and a while while sitting at a light or stop sign, in gear?? My 35th and my 95 both automatics seem to do this. I've already changed the IAC on both of them and they still do it. I haven't made any other mods (intake wise) on either of them yet. Wanted to get them right to start with before I went messing around with them. Seems if I have the AC on I never see an idle problem, although needed down here, I hate the AC...

RJ
 
TB

On your BBK TB,there is a flat head screw on top,try turning it up little by little until you have disered RPM.I learn it the hard way by changing part's left and right and all i need is a small bloody screwdriver.Just throwing in my $.02 CND.Good Luck.
 
Lugen said:
What happens is if I'm in neutral OR Stopped at a light it will for a split sec sputter, or miss(?) happens once twice a min or every few min, no set pattern
I seem to be having the same thing happen now. Before my DIS went south, I was having the same thing happen, only it was more like a cut-out. Now, it just seems to be an occasional misfire, then everything's fine. If I weren't watching the tach, I probably wouldn't even notice it. Its only happened once or twice that I've noticed. Oh well.. if you all find anything out, post back and let us know.
 
kamakazie_1 / RJ...yes

Yes, that's exactly what it felt like. Check to see if you have that vaccum problem. If not, at least you've eliminated it as a possiblity.
 
Back
Top