Random misfire during cruise

Guess I should try and fix this before Davis.

b230 +16v +t
e85
3in maf
custom chipped ecu, changed fuel map and disabled lambda feedback
base 16v turbo ignition map, wasted spark board using the recommended range rover coilpack
BP7RES plugs

This issue has been around for a while. It runs great in boost but during a steady cruise it'll randomly hiccup and spike rich on the wideband. When cold its worse, sometimes it'll go full rich for a second before taking off. The only thing I haven't really checked are the plugs and wires, but they have less than 5k on them since the rebuild.

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Xeroni said:

The only thing I haven't really checked are the plugs and wires, but they have less than 5k on them since the rebuild.

Click to expand...

Maybe try the iridium equivalent plug? (BPR7EiX? BPR8EiX?) i use those in my chipped b204gt T16v, with very satisfactory results but i am not running e85. I have in the past on a B230FK and i remember that cold starts and cold running was always a bit problematic, specially in temps below freezing. (throttle body freezing up?)

Maybe pull a plug after a light cruise and have a look-see if it self-cleans enough. Maybe the heat range of the plugs is wrong?
You might as well check the plug gaps while you are in there.

just my 2ct

Janspeed said:

Maybe try the iridium equivalent plug? (BPR7EiX? BPR8EiX?) i use those in my chipped b204gt T16v, with very satisfactory results but i am not running e85. I have in the past on a B230FK and i remember that cold starts and cold running was always a bit problematic, specially in temps below freezing. (throttle body freezing up?)

Maybe pull a plug after a light cruise and have a look-see if it self-cleans enough. Maybe the heat range of the plugs is wrong?
You might as well check the plug gaps while you are in there.

just my 2ct

Click to expand...

Probably a good idea. I haven't removed them since I rebuild it.

I’ve had the same issue with my +t. I just assumed it was old wiring and have started switching it to ms3.

The rich spike is not a rich spike it is an consumed oxygen spike from the misfire.
I would use standard copper core plugs for a turbo model.
Check your cap and rotor closely.
Then replace the garbage bougricord plug wires. They don't seem to last very long.
Taylor and NGK both make nice plug wires that last.

Interesting statement, as I was always told to grab Bougicords whenever found them in the yard

I wonder if a high output coil can cause them to deteriorate?

I installed a new set and they were junk in a very short period of time.
Caused me some setbacks fighting ignition problems because I assumed the wires were good as I had installed them new.

Check them with an ohm meter.

I have good luck with Kingsborne wires as well.