Diagnosing a misfire

USA car? must I GUESS?
so you have 2 coil packs. ????
called wasted park
seems you typed the displacement wrong, !!! 2.2L is 4 banger...
1 and 4 fire as a pair
2 and 3 , fire as a pair , in series

so if the spark wires open , you loose a pair,
say #1 opens, you loose #4 with it.
they are wired in series.
if one spark wire grounds out , you lose only THAT spark plug.
but why would you get the odd pack to pack cross talk.
(assumes you have the HV wired right. correct?)
the packs cant be wired up willly-nillly.
this is the 2.2L coil pack.
and IS wasted SPARK system. for sure.
and can not be mixed up
the PCM is hard coded for 1,3,4,2 firing order.
and must be wired right. did you meddle here?
if you unplug the 2 one right , this must not make the 2 on left work.
pulling 1 wire, only kills the adjacent wire. normal.
see the pairs there, at the bottom see those hiddencoil packs mail coils molded to case?
if you are wired right and you have cross talk from 1/4 to 2/3 bank
the pack is bad.

by cross talk i mean, 1;3 effect 1/4 or the reverse.

change the coils but most likely a bad ecu

Is there a coil per cylinder? That's sounds like a faulty coil, that can cause a misfire in a cylinder. It's relatively easy to test. Start your engine and when the car rpm's drop, remove the coil socket from cylinder number one and if the car hesitates more that means that cylinder is working good, then reconnect and continue with cylinder number two, remove the coil socket and look very careful for hesitation and reconnect and so long until you check all off the cylinders. If you disconnect a coil of any cylinder and the engine remains the same, doesn't hesitate more, then that cylinder isn't working, so change that coil. Begin with cylinder number 4 if you want to cause of the scanner reference.

mass air and tps would be 2 most common causes.

For the 1994 Isuzu Trooper 3.2L DOHC V6:
Cylinders:
.......(back).......
|..5.............6..|
|..3.............4..|
|..1.............2..|
.......(front).......
Coil Connections:
............(back)...........
|.1..4.|..|.6..3.|..|.2..5.|
............(front)............

Let me know if this helped....Thanks for using FixYa.com!

if the battery starts the engine than the computer has enough voltage to operate the system, so that is not the problem, do u have any electronic fault codes, u willneed the system scanned and the engine checked for a misfire, perhaps u need new plugs and plug wires?

Check fuel injector and compression in cyl. #5.

Misfire codes (including P0301 (THIS WOULD BE YOUR CODE), P0302, P0303, P0304, P0305, P0306, P0307 & P0308) indicate that there is a misfire in a cylinder, the last number indicates which cylinder has the problem. If something is causing a miss in random cylinders or is affecting all of them, a P0300 misfire code will be stored in the car's computer. It's always smart to begin with the basics. Also consider the mileage and service history when diagnosing a misfire. Higher mile vehicles are more inclined to have mechanical issues with the engines, like low compression from worn valves or rings etc. Any accompanying codes should also be considered in case they may be related. If the spark plugs are worn (excessive gap) or the car is past due for a tune up, it may be smart to go ahead and start with spark plugs and spark plug wires and go from there.
The most common misfire causes on the cars I've worked on have been:

1. Spark plugs
2. Spark plug wires
3. Ignition coil
4. Fuel injector
5. Wiring to fuel injector
6. Timing Belt (IF EQUIPPED)
7. Vacuum leak or stuck open EGR
8. Contaminated fuel or bad fuel pump
9. Weak compression
10. Blown head gasket

Obviously there are many different types of cars, so a service manual for the specific one that you are working on may be required to help pinpoint the misfire you're looking for, but hopefully this will direct you to some of the most common causes of misfires in cars of today.
When diagnosing a SES light, it's best to start with a quick scan with a code reader. If checking the engine's mechanical integrity specialty tools, like a compression tester, an exhaust back pressure gage or cylinder leak down tester may be needed.

codes 03-40 are misfires on cylinders 3 & 4 and 325 is ur knock sensor if u had bad gas/water in tank or need tune up and those 2 cylinders misfired could set off code for knock sensor or visa versa as to abs light sheck sensor wires for connection and or damage none observed have rescanned and find out if sensor or unit if sensor scan code will tell u which one ur directional usually blinks faster on the side with the bulb out

1998 isuzu rodeo wont start no spark,no injector pulse