4g63 Coil On Plug 201
This is a continuation from my earlier coil-on-plug how-to video. I was
troubleshooting an ignition problem where I couldn't Boost over 14 PSI without misfiring or
backfiring despite having an ignition amplifier, and this is what worked to
completely resolve my troubles.
There's lots of information about what parts work well on a 4g63 (and their
relevance) as well as lots of reports about people having ignition problems
once they're installed. I noticed that there's not really any instruction
available regarding ideal methods for trimming the longer Chrysler boot
down to the size and shape for a 4g63 setup. Some of this could be due to
the depth of various COP mounting plates, but this video is intended as an
effort to help fill that void regardless of why.
If the boots are not trimmed properly, then as combustion chamber pressure
increases, the possibility of the spark arcing from the plug into the plug
well is possible. This can happen on improperly insulated plugs, or as a
result of an old worn boot. The solution if your coil resistance is
good... is to run down to NAPA and buy yourself a set of new boots. They
come with new springs. They just need to fully-sleeve the spark plug's
ceramic insulator, and make good electrical contact internally. If air can
get in and out, so can spark.
FYI: When inspecting older worn-out boots, wherever spark leaks through
leaves a white spot.
4G63 Dragster - 7.77 at 171 MPH
Only the 5th full pass down the track for the car and we broke into the
7's! This pass was at 36 PSI. The only changes since the last pass were a
fresh set of plugs and we tweaked the tune a bit.
6 bolt 4g63 in 2g Eclipse GSX cylinder head removed in under 10 mins
Removing the head of a 4G63 in 10x speed.
The project got delayed a few months. After finishing it and cranking it
over, Interference in the cylinder was discovered. Shamefully, I admit my
mistakes were: 1) Not putting the spark plugs in immediately after
installing the head. 2) The bad habit of using my Valve Cover as a parts
tray and 3) Putting off the project too long, so I didn't recognize a
missing bolt from a custom fabrication.
The head needed new valve seats, valves and some welding. Wiseco and the
machinist both thought I'd be OK running the piston after smoothing out hot
spots, but I ordered a new piston not wanting to risk the deep gouge in it
with the high Boost I plan to run.
Peace of mind is priceless.
The danger in being over confident is sometimes you skip triple checking
stuff. I've built that engine at least 5 times and got careless.
You can see the port work I did on the head @
http://www.southernutahautos.com under "Tech Tips" and "Beyond Bolt-ons"