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Test a Coil Pack?
- Thread starter eyesac
- Start date
MJR
NAXJA Forum User
- Location
- Costa Mesa, CA
eyesac said:
Not likely the coil pack since there are 3 coils within it and each feeds 2 cylinders unless it's the contact to the plug. What plugs are you using?
Cheap Autolite Platinums. I hear you about the only real possibility is a contact somewhere (unless only one lead of two is bad coming from a coil). My problem is it's not like I can just pull a S/P wire and test the spark on this system... My only alternative is to buy a new coil pack and try it out ($138), unless of course someone knows a good way of testing this thing.
MJR
NAXJA Forum User
- Location
- Costa Mesa, CA
Never use Autolite plugs. Get some champion copper plugs or plain NGK V-power plugs.
MJR
NAXJA Forum User
- Location
- Costa Mesa, CA
eyesac said:Ok fine, but that's not the problem. I changed the plugs and the code (and misfire) remains. So I guess there's no way to test the coil...
Frankly I wouldn't rule out the plugs even (can't tell you how often we have this issue at the dealer) if they are new. The test is just to do a resistance check but I doubt it will show anything. There is also a TSB flash for misfire on hot restart (00-01) which involves reprogramming the engine controller. Also if you get multiple codes the cam sensor could be going out of sync due to a drive housing that could be going out.
IGNITION COIL RESISTANCE - 4.0L ENGINE
PRIMARY RESISTANCE 21-27°C (70-80°F)
0.71 - 0.88 Ohms
COIL RAIL - BLACK 4 WAY CAV CIRCUIT FUNCTION
1 K19 18GY IGNITION COIL NO. 1 DRIVER
2 A142 18DG/OR FUSED AUTOMATIC SHUT DOWN RELAY OUTPUT
3 K17 18DB/TN IGNITION COIL NO. 2 DRIVER
4 K18 18RD/YL IGNITION COIL NO. 3 DRIVER
Last edited:
frank36
NAXJA Forum User
- Location
- Pennsylvania
Is your jeep actualy missing all the time,or are you just worried about the code?Chrysler computers are notoriose for picking up missfire codes when there are no real problems.If a plug got a little fouled on a cold start ,it 9 times out of 10 will set the code.Did you reset the computer after you changed plugs?The computer will store some codes for up to 50 start cycles unless you reset it.
MJR
NAXJA Forum User
- Location
- Costa Mesa, CA
eyesac said:
As I said there are 3 coils in the rail. You have one common feed wire (pin 2) and three trigger wires (pins 1, 3, and 4) so you test each one. The reason I do not think it's the coil rail itself is because if you had a problem with one of the coil packs it would affect 2 cylinders not just 1. As each coil is triggered it makes a spark in 2 cylinders, one at the top of the compression stroke, and the other on the exhaust stroke (waste spark). If it's just one then maybe the contact for that plug (someone was selling I thought a repair kit).
LiamN
NAXJA Forum User
- Location
- LI, New York
Going through the same problem.
there was a TSB on the coil pack for 2k-2k1 4.0L engine... it is as follows:
1) the misfire is generally on cylinder 3
2) it is caused by a sleeve causing a faulty connection to the plug
3) the sleeve is easily repairable by simply buying a new sleeve from the dealer.. 2 bucks.
My xj is all out of whack right now.. idling rough, loss of power, and sputtering like a a badly shifted standard transmission between 2500-2700 rpms.
coil pack is suspect, hope i was able to help
there was a TSB on the coil pack for 2k-2k1 4.0L engine... it is as follows:
- TSB #0900303 -- 4.0L MULTIPLE CYLINDER MISFIRE. *TT (NHTSA ID #10003538, AUGUST 01 2003
1) the misfire is generally on cylinder 3
2) it is caused by a sleeve causing a faulty connection to the plug
3) the sleeve is easily repairable by simply buying a new sleeve from the dealer.. 2 bucks.
My xj is all out of whack right now.. idling rough, loss of power, and sputtering like a a badly shifted standard transmission between 2500-2700 rpms.
coil pack is suspect, hope i was able to help
MJR
NAXJA Forum User
- Location
- Costa Mesa, CA
LiamN said:
Well TSB 09-003-03 (99-01 XJ and other) is not as you describe. That TSB involves running Mopar combustion chamber cleaner through the engine to clean out carbon deposits and if necessary rotating the exhaust valves 90 degrees if they are not rotating themselves.
TSB 18-031-03 (00-01 XJ) involves a #3 misfire after a hot restart and installing a fiberglass sleeve (part # 56028371AA) on the # 3 injector.
TSB 18-039-03 (00-01 XJ) involves a flash reprogram for a rough idle after a hot restart and can be aggravated by the use of fuel with high ethanol content. The cooling fans will cycle on more often.
All these TSB's are more specific in what conditions and what build each vehicle is so they might not apply to your specific vehicle.
McQue
NAXJA Forum User
- Location
- Plainville, Connecticut
MJR...you da man!
Great job getting the correct info out to everyone! After working in the computer field for 30 years, you would probably be amazed at the problems ( and customer satisfaction issues) I have seen caused by incorrect repair data being distributed...
McQue
Great job getting the correct info out to everyone! After working in the computer field for 30 years, you would probably be amazed at the problems ( and customer satisfaction issues) I have seen caused by incorrect repair data being distributed...
McQue
sixditchoffroad
NAXJA Forum User
- Location
- Denver, Colorado
Ok, well I have a similar prob. I took the #1 wire off the plug held it close to the plug end and had my little brother spin the motor... No spark. Took the wire off the coil pack and left the wire on the dist., held it close to the pack and had my brother spin the motor.... No spark. I found some carbon under the cap and the rotor top is burnd a bit. So here's the thing, is the pack bad or what?? I guess I have to ride my specialized to work tommarow.
kmanxj5050
NAXJA Forum User
- Location
- Reed City Michigan
LiamN mine is doing the exact same thing i just bid on a coil pack off ebay, for 36$ way cheaper than 140 at auto zone, did this fix your problem?
CMK4425
NAXJA Forum User
- Location
- Baton Rouge, LA
O'reily Auto Parts sells the coil pack for $99.00 if you have one in town.
