3.4 dohc miss fires.
Topic started by: ricksmastermix, Date: 01-11-2019 05:42 PM
Original thread: http://www.fiero.nl/forum/Forum2/HTML/142158.html

ricksmastermix (rbeem@windstream.net) MSG #1, 01-11-2019 05:42 PM
      My 3.4 dohc 86 Fiero seems to idle OK, but as soon as I accelerate, it starts to miss fire on one or more cylinders.

It's cold outside, so I want to go out to garage with a troubleshooting plan. Any ideas?


Daryl M (daryl.miglia@gmail.com) MSG #2, 01-11-2019 10:28 PM
      Rent a heated garage???
Sorry, I just had too.

msweldon (marc.weldon@mindspring.com) MSG #3, 01-12-2019 11:03 AM
      Could be a failing ICM, coil pack(s), wires, or 7x CKP...

OBD II or I LQ1? MAP sensor only or MAP and MAF? Any DTCs set?

Maybe check for a carbon fouled spark plug to locate the bad ignition circuit.

ricksmastermix (rbeem@windstream.net) MSG #4, 02-09-2019 08:50 AM
      OBD I

I will check the plugs, coils and ICM first.

Dennis LaGrua (dlagrua@comcast.net) MSG #5, 02-12-2019 09:43 AM
Originally posted by ricksmastermix:


I will check the plugs, coils and ICM first.

Good first steps. Use a spark checker on each plug wire, check fuel pressure and fuel quality. Then scan to see if engine is running lean.