new project car, 91 LX

[jerrys84]

sold my 84 GT. the 91's Body is really nice and rust free.

so then here we go again.

first question, the car currently has a 4 cyl with 8 spark plugs, what's up with that?


and now for the mod questions;

anyone running the 302 motor from jegs, GT-40X aluminum heads, rated at 345 hp. $3,300.00.

Summit also has a super duty T-5 for $1,100.00.

both seem like decent prices.


future mods will include;

engine and trans swap
headers and quality (quiet) exhaust
8.8 with 3:73's
sub frame connectors
aluminum radiator
drag radials

this one will be a sleeper!!

[84LX89GT]

The 2.3L mustangs from '90-'93 i believe had the dual plug 2.3L. This is what's called a waste spark ignition system. The coil fires through one side when it's supposed to ignite the air fuel ratio, jumping from the center electrode to the ground electrode, through the block, to the ground electrode of the partner cylinder's plug and jumps back across to the center electrode of the plug back to the coil secondary negative side. This is, in theory, also supposed to light off any risidual exhaust left during the exhaust stroke of another cylinder as well as light off the intake within the same coil firing. The cylinder pressure is very low in the exhausting cylinder so jumping the gap takes very little effort.
Here's from a ford powertrain control/Emissions diagnostic manual:
"The 2.3L Multi-port Fuel Injection (MFI) Truck (Dual Plug) EI (Low Data Rate) Ignition System
(Figure 6 ) consists of a crankshaft-mounted Dual hall Sensor, two 4-tower DIS coil packs, and a Ignition Control Module (ICM).

The EI (Electronic Ignition) eliminates the need for a distributor by using multiple ignition coils. Each coil fires two spark plugs at the same time. The plugs are paired so that as one fires during the compression cycle, the other fires during the exhaust stroke. The next time the coil is fired, the plug that was on exhaust will be on compression and the one that was on compression will be on exhaust (the spark in the exhaust cylinder is wasted but little of the coil energy is lost). Two coils are mounted together in a "coil pack". Each coil pack has two tach wires, one for each coil. Since there are two plugs per cylinder, two coil packs are required. One is called the Right Coil Pack and the other, the Left Coil Pack. The Right Coil Pack and right side spark plugs operate continuously, but the Left Coil Pack and left side spark plugs may be switched on or off by the Powertrain Control Module (PCM). The PCM computes the spark angle and dwell for the ignition system."

What i've always wondered is what would happen if you swapped the exhaust's plug wire over to the cylinder that's firing then and having the coil fire across one plug, and back through the other in the same cylinder instead of having partner cylinders firing. I've never tried it, so it may not do anything, but it's just a fun thought, it may help the car get out of it's own way a little bit. or it may cause a misfire....who knows?