mis-firing when car warms up
 

need a little help here,my 85' 928 32v starts mis firing when it warms up completely?thought it was intake leak,replaced all lines,gaskets,boots,new fuel pump and filter,when i first start and take off no miss,pulls strong and hard threw all five gears,when it gets hot it acts like its down a cylinder,spitting and popping?? let the car cool down and it runs normal!!! maybe plug wires or cats in exshaust?? i pulled the oxy sensor wire miss got worst? any help would great

open hood ,
remove the air duct tubes,
run car till hot,
look at the spark plug wires for fireflies at temperature, (NOTE do this when its dark)

Also inspect the coil wires make sure neither one is touching anything and that both ends are clean.
If the coil wires have been rubbing on something its a sure bet they need replacement

My guess is you need new wires as well as new coil wires,
NOTE some less expensive sets dont include new coil wires

I sell all 10 wires for $89 + $5 shipping in the states: OE Beru, just unscrew all 20 wire ends, screw them onto the new wires: it's that easy. PelicanParts sells my DIY 911 wires, but I still sell the 928 wires directly. I have Black & red available, + a great non-beru Blue wire.

Mark

If you go with an "econo" kit (no ends), make sure to test and replace any of the old ones out of spec.

If your doing the work yourself, its not a bad way to go, but if your paying a mechanic, buy a full set with the whole loom premade and ready to install (keep your old ends and loom parts for use or sale to others).

thanks for help!!! sorry mark already purchased wires caps a rotors,but wish i would have gottin yours,

Purchased but not prior to this issue I hope. ;)

As long as you stick with the factory Beru wires you should be fine.

/\ agreed: our ignition systems are extremely sensative: you cannot run any other type of ignition wire than the OE Beru w/o odd results: they're a solid-core wire.

Mark

Beru wires are costly. I use the Economy Wires from 928 Intl on both 928's without issue.