How do I test coils?

[Q_SHIP]

I think that may be my problem. The car is deffinatly not firing on all 8. I think the coils are the first place to start.

Refer to this thread.zerothread/199342

But now the car even idles bad. Thanks guys.

[Q45tech]

The normal method is to acquire a few NEW coils and 1 by 1 replace and test until you find the bad one/ones.

[elwesso]

Theres a resistnace test in the FSM.

[Q_SHIP]

Theres a resistnace test in the FSM.

Can you point me in the right direction in finding that?

[Q_SHIP]

also, is an injector resistance check the same as a G50?

Anybody want a lowerd Black black Y33 for $5500. God Im so over this car.

[Rex]

also, is an injector resistance check the same as a G50?

Anybody want a lowerd Black black Y33 for $5500. God Im so over this car.

I'll trade you a nice "Muscle Cruiser" style motorcycle straight up .

[Raxephon]

Can you point me in the right direction in finding that?

Here you go.
Modified by anlasak at 3:44 PM 10/12/2006

[Q_SHIP]

The normal method is to acquire a few NEW coils and 1 by 1 replace and test until you find the bad one/ones.

You're kidding right?

Maybe thats why the bills at Infiniti are insane. Throw parts at it till its fixed.

[Q_SHIP]

Here you go.

Modified by anlasak at 3:44 PM 10/12/2006

Thanks, Thats what I was looking for.

[Qproject]

Q-ship, let us know how everything works out. I feel for you with all the problems your having.

[Q45tech]

Coils which partially fail or just have below limit high voltage that occurs randomly are very difficult to test..............a normal failure will show up as a OBD2 code.An abnormal [unfortunately common] weakness will require the substitution or just total replacement.............you can spend an hour getting the test equipment connected and still not simulate the conditions where the failure occurs.

Many times just removing the coils cleaning them up of oil film replacing the plugs and reassembly will solve many problems for awhile.

Misses at cruise are easy as the OBD2 watches O2 for a rich cylinder and reports that cylinder as a misfire................accelerations and idles or WOT misses are more difficult and beyond the ecu's mental powers to resolve [system not in closed loop].

2002 and later have enough computer power to almost always zero in better even when not in closed loop.

[Qproject]

q45tech, what do u mean by closed loop of the obd2 ?

Coils which partially fail or just have below limit high voltage that occurs randomly are very difficult to test..............a normal failure will show up as a OBD2 code.An abnormal [unfortunately common] weakness will require the substitution or just total replacement.............you can spend an hour getting the test equipment connected and still not simulate the conditions where the failure occurs.

Many times just removing the coils cleaning them up of oil film replacing the plugs and reassembly will solve many problems for awhile.

Misses at cruise are easy as the OBD2 watches O2 for a rich cylinder and reports that cylinder as a misfire................accelerations and idles or WOT misses are more difficult and beyond the ecu's mental powers to resolve [system not in closed loop].

2002 and later have enough computer power to almost always zero in better even when not in closed loop.

[Q_SHIP]

Coils which partially fail or just have below limit high voltage that occurs randomly are very difficult to test..............a normal failure will show up as a OBD2 code.An abnormal [unfortunately common] weakness will require the substitution or just total replacement.............you can spend an hour getting the test equipment connected and still not simulate the conditions where the failure occurs.

Many times just removing the coils cleaning them up of oil film replacing the plugs and reassembly will solve many problems for awhile.

Misses at cruise are easy as the OBD2 watches O2 for a rich cylinder and reports that cylinder as a misfire................accelerations and idles or WOT misses are more difficult and beyond the ecu's mental powers to resolve [system not in closed loop].

2002 and later have enough computer power to almost always zero in better even when not in closed loop.

Great info! Thanks Tech.

[Raxephon]

q45tech, what do u mean by closed loop of the obd2 ?

Closed Loop

[Q_SHIP]

So let me get this straight, if it's not zero ohms, I should be ok? How is 1.3 Ohms?

[Q45tech]

Measure all coils [the same way] and create a statisical good number.

The problem usually occur in the secondary coil [high voltage] where leakage keeps peak voltages from rising at the plug fast enough to overcome the leakage.

A cheating way to test is to create adapters/extenders to pull the out of the well [high voltage extension] and jumpers to plug into wiring so that a SPECIAL HIGH VOLTAGE PROBE can be used to view the spark voltage rise time on an oscilloscope.

http://www.pc-oscilloscopes.co...d=543

http://www.picotech.com/auto/e....html

[maxnix]

An abnormal [unfortunately common] weakness will require the substitution or just total replacement.............you can spend an hour getting the test equipment connected and still not simulate the conditions where the failure occurs.

My coilpack failure was only at elevated operating temperatures caused by high ambient temperatures (>95° F).

OBD II isolated the cylinder. Switching coil pack loaction only, OBD II fault code moved with coilpack, then replacing with a new one confirmed the bad one.

I think there are only two different sytles of coilpacks employed on VH41DE. My failed coilpack was the most common one (like on cylinders 2 and 4).
Modified by maxnix at 3:40 PM 10/13/2006

[Q_SHIP]

Well, I tested all of them with the same reading of 1.3-1.4 ohms. I'll have to dig deeper now.

[Q_SHIP]

What are the chances that my issues are coming from Bosch plugs? They perfeormed flawlessly for 20,000 miles. Could they just be shot at this point? I pulled them all and all the electrodes are still there.

[maxnix]

What are the chances that my issues are coming from Bosch plugs? They perfeormed flawlessly for 20,000 miles. Could they just be shot at this point? I pulled them all and all the electrodes are still there.

Try a search on Bosch and you will rip them out after you read the posts.

The engine was designed for the NGK laser platinums which work flawlessly. Why deviate from perfection?

[Q_SHIP]

Well thats why Im asking. Could they have just done this out of the blue? They worked GREAT in the car for over a year. What could make these plugs bad if all the electrodes are in nice shape?

[Q_SHIP]

Well, I pelpaced all the Boschs with NGK's. Same problem. Cost $110 but atleast they are the right ones now.

I hate this fukin car at this point. What a pile of crap.

[goody90q45]

Did you ohm your injectors?

[maxnix]

Well, I pelpaced all the Boschs with NGK's. Same problem. Cost $110 but atleast they are the right ones now.

Best to correct the car's deficiencies in diagnosing your problem.

Have we missed your post of the OBD II scan?

[Q_SHIP]

No I have not. Is the procedure the same for a Y33 as a G50?

[Q_SHIP]

Best to correct the car's deficiencies in diagnosing your problem.

Have we missed your post of the OBD II scan?

The sacanner I have just came up with "random multiable misfrires detected"

I was thinking "well I could have told you that"

[Q_SHIP]

As another note to add, I just noticed the exhaust has a very heavy and thick black residue inside the tail pipe.

[Q45tech]

Since the primary of the coils tested consistently obviously the problem is in the secondary winding and or the insulation and or the extenstion to the plug.

When you have a bad plug wire you change the plug wires if so equipt. In this case the plug wires are part of the coil assembly.

Don't confuse cost of repairs as being meaningful or germain on a $50,000 vehicle.

I googled "coil on plug failure" and got pointers to GM and Ford problems, "coil on plug" returned 54,000 hits most explaining how to trouble shoot and selling you test equipment.

[maxnix]

The sacanner I have just came up with "random multiable misfrires detected"

I was thinking "well I could have told you that"

OK, I am an OBD II dummy, but when I got a scan, the particular cylinder misfiring was identified. Which code was displayed? Are you sure of your scan tool?

[Q_SHIP]

No, it's just a chaep one. Getting a pro to scan the car today.