Fox 91 mustang spring time woes

Jimmer009

Member
Jan 4, 2022
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Hey all. So my 91 mustang speed master heads 190cc. X303 cam, megasquirt 2, msd6al. 42# injectors.

I have a misfire and a popping noise. The popping is intermittent. But the misfire is pretty consistent.

I replaced the plugs (they were black/soot covered) and cap and rotor. The wires are new last year as well as the coil and tfi module.

I have in wire test light. It shows good spark most of the time then it dies down and will then come back. As the motor has a hard time idling because of the xcam (low vacuum) I'm not a fan of it but will replace it when I get the budget to do it.

I have checked timing and I don't know where to from here?? Any help is appreciated.
 
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Thanks for the reply. I don't think it's much in the tune. I had the same tune in for awhile now. It even ran great last fall. I'm leaning more towards a hardware issue. I did post a log up on the megasquirt forum.
 
Im gonna look into the pip tonight. I don't see any fuel so I'm thinking it's not o rings. Any tips to checking the pip?? I'll Google it and go from there. I really don't want to tear my disturbor apart.
 
So thanks for the help and suggestions. Shuttleman guess it. My buddy came over and we took his disturbor out put it in mine and all is good now. Granted I need a disturbor as I'm not gonna fix the old one. But thank you guys
 
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Why would you not fix the old one? Most if not all of the remans and "new" ones like the MSD's are junk. All you need is a Standard Ignition LX222 and watch a YouTube video on how to replace the stator / PIP / hall effect sensor.
 
Thanks. And I didn't give much thought to rebuilding it. I have a press. Granted it's a big 10 ton press. It will work. But a new remand one is cheap enough to just buy it. They come with a new tfi module and cap and rotor. I might just do that then have a spare.
 
I am telling you do a search on any Mustang site and the remans are just garbage. If you enjoy being stranded with a new distributor go for it or you can spend a little time and not have to worry about it.
 
Ok I am in shock at how my car runs. It's faster than ever. It used to hesitate above 5000rpms. That's gone and it just goes. It's a stock disturbor my buddy let me use. So I'm thinking I'm gonna rebuild seeing especially if the other ones are junk.
 
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