Help with miss

[DownSouth]

I hope you guys can help me diagnose my cars issue. I have a ‘93 3.1L base Beretta that has developed a miss that is affecting its power.

History
I just had the air intake and plenum off 3 weeks ago so I could get to and repair the supply line fitting to the heater core. Upon reinstallation of the plenum, I replaced the crank case breather hose and upper intake gaskets. The car ran fine for a week or so, then one morning upon start-up, it had a miss. Idle seems to be “normal” except for the miss. Meaning the car does not struggle to maintain idle. In park, it will rev “normally,” again except for the miss. The main issue is under load. It does not bog down, but rather it struggles to accelerate from a stop even with the gas peddle to the floor.

So far, I’ve replaced the plugs, plug wires, and fuel filter. Problem is still there. Also, I can hear an intermittent rattle/knock in the cat, especially once the exhaust has heated up. I assume this is from the exhaust pipe shaking from the miss along with a bad cat converter.


I would appreciate your input. Thanks

[88gtz]

Check you're coils, my 94 z was about the same ended up being a bad coil...

[DownSouth]

I unplugged each plug wire while the car was idling. Number 3 and 6 had no effect while the others did. Service manual shows 3 and 6 are on the same coil. Hopefully that's the problem.

[DownSouth]

What size bolts hold the coil? Are they hex or torx head bolts?

[Chad91GTZ]

That's a 5.5mm iirc. But its early.

[3X00-Modified]

correct

[DownSouth]

Got the new coil on,.......problem solved. Time to move on to other issues. haha

Thanks

[Chad91GTZ]

Sweet!