ignition coil checking...

Well, I was finally able to remove the ignition coils off my car (rear ones were a real pain!)
In any case, following instructions off the Haynes manual, I placed positive lead wire to terminal 1 and terminal 2 to the negative. That showed no numbers to indicate infinite resistance.

Now for the continuity i reversed the leads and checked that. They seem to be above 50ohms each. With my reader, it only shows below or above 50ohms. If below 50ohms it beeps and that's it which indicates a short.

Then I placed a lead to terminal one, and another lead to the side on which the spark plug connects directly on in the boot. That checked out to be infinite aswell.

So my question is, did I do this all correctly? If not, what did I do wrong? If I did it correctly, what should I check next? I was thinking spark plugs since they're already exposed.

Problem: The problem which i'm having is the fact that i feel thumps and bumps at idle. whether in "D" or "P".

99 SE-L

I have the exact same problem with my 99 Maxima GXE Auto (59k). Got the 60K tune up done thinking it may solve the problem. Did not seem to help much.

I have noticed a few complaints on the NHTSB site (and other forums as well) that suggested bad ignition coils and that Nissan issued a TSB on it some time back. In several posts, I have noticed that dealers tend to replace all 6 coils instead of just the defective ones. This obviously gets very expensive.

The only other cause that needs to be investigated is the fuel injector. As the rough running seems to be happening (in my case) in P, N as well as in D and R - the only correlation seems to be engine speed, the situation gets better as the revs increase with the worst when idling. I want to try a good fuel injector cleaner - any suggestions?

You seem to be on the right track here. Hopefully somebody who knows their way around this issue will stop by to help.

After I had this Service Engine Soon light on, I took my 99 Maxima to the dealer. They ran the diagnostic test and found the code "ignition signal primary" but could not specify which cynlinder having a bad ignition coil. They recommended to replace all six which costs over $700. My car starts getting rough during the driving. I bought a Haynes book to find out how to replace these coils my self that I might save over $200 for labor fee. Took all ignition coils out were not that bad except the ones on the rear. Follow the Haynes repair book, I connect a positive lead to terminal 1 and negative to terminal 2, it did not show anything. By reverse, it shown ~456 ohms. It also did not show any ohm as the book said when connected between the terminal 1 and another that connects to the spark plug boot. The result was consistent for all six coils. I just wonder that Haynes book has mislead this info. Since I could not find any particular coil having different result. I intend to replace all six but just wonder has Nissan improved or redesigned these coils to be last longer. Otherwise, we, Maxiam owner, have to replace them again after driving another 50k miles. By the way, I have a question if someone could help me. How do you locate the cynlider number or coil number is located on engine. Thank you.

With the same "ignition coil" problem, I replaced all 6 coils (cost: $450.xx) for the "misfiring" and get full horse powers back.

To investigate "coil problem", I set up a test circuit with a 12-14VDC @10A power supply and a 5 Vp.p signal generator to fire a spark plug.

Results: ALL 6 COILS ARE GOOD (Firing fat purple spark), Only when the ground terminal (the center pin of the connector, labeled as "G") and the magnetic core of the coil is connected with a wire. If the wire is replaced by a 5 to 15 ohm resistor, the coil fails to generator a good spark.

Then I went to my car to check the resistance between the ground wire (from the coil connector) and the chassis (the point that the spark plug is mounted on), it measures 90 ohm!.

Since I can't identify any broken coils (I knew I had two "bad" coild each for front and rear rows), I thought if I made a jumper between the chassis and the connector(ground), it may solve the problem. But it may damage the ignition controller/ECM.

Just a though, please do not try the "jumper" on your car if you are not confident or unwilling to take the risk.

Any though? Thanks!

I have some ignition coils in great condition.
$50 shipped OBO email me at:
[email protected]
if interested

whats up everyone I am currently in the middle of a terrible experience with Peachtree nissan in chamblee Ga...my car has been stalling out in park and also if I tap the gas while in park the rpm's drop to around 300rpm at which point the car almost cuts off and the lights dim. check eng light came on on 11/30/03 took car to dealer on 12/1/03 I was told that the coils needed replaced I requested to speak to the tech who advised me that the code he got suggested the coils needed replacing I asked why he wasnt replaced the bad coil(s) only he stated there is no way to determine which is bad DOES ANYONE KNOW IF THIS IS TRUE? my independent says the code should tell you which coil is bad anyway after paying them 668.00 the car is now stalling out in drive as well as park they replaced the spark plugs no help! I called corporate and they just sent me back to the dealer if the car is still doing the same thing it obviously was not the coils any ideas?

go to cybrrpartspro and put in year and model and it will tell u anything about checkin your coils u need to know. As far as I know connect terminals 1 and 3 on lowest setting and should come up +-.9 ohms if it is good. if it is way off they need to be replaced. check for yourself......instructions and all

After I have found which cylinder having a problem with bad ignition coil. I just changed the coil instead of all six. Now my Maxima has been running good so far with additional 15k miles on it.

tim, my 1993 Maxima SE is having the same problem (rough idle, sparatic RPM, lights dimming, etc). In addition, my tail pipe has a put-put-put release (almost as if it is coughing). A few months back, i replaced a bad coil (front left) - so i thought it could not be the coil. But When i took it into my mechanic, he tested the coil and determined that the same coil i replaced a few months back is bad again! It seems that if i continue to buy new coils to replace the bad one, it will also get damaged! Does this mean that this is some sort of electrical problem? How can i find what the root of the problem is (everytime i put a new coil in, it gets "burned" and damages)? Any ideas anyone?

whats up everyone I am currently in the middle of a terrible experience with Peachtree nissan in chamblee Ga...my car has been stalling out in park and also if I tap the gas while in park the rpm's drop to around 300rpm at which point the car almost cuts off and the lights dim. check eng light came on on 11/30/03 took car to dealer on 12/1/03 I was told that the coils needed replaced I requested to speak to the tech who advised me that the code he got suggested the coils needed replacing I asked why he wasnt replaced the bad coil(s) only he stated there is no way to determine which is bad DOES ANYONE KNOW IF THIS IS TRUE? my independent says the code should tell you which coil is bad anyway after paying them 668.00 the car is now stalling out in drive as well as park they replaced the spark plugs no help! I called corporate and they just sent me back to the dealer if the car is still doing the same thing it obviously was not the coils any ideas?

... thumps and bumps at idle. whether in "D" or "P". ..


When components contain electronics, resistance measurement most often is not valid. The components get hot, and fail only when current flows through. Test by replacement is the only way... 50$ pop, also swap plugs.

Test all sensor first: buy or rent autozone tester. Download manual from Favorite Links at left: http://www.cardomain.com/ride/748507/9

Take a look at my experience with ignition coils in the following thread on this site.

1999 Infinity I30 Engine misses sometimes

My car was a Maxima 1999, same issues, rpm dropoffs in Drive at idle. Flashing engine light on hard acceleration. Took me a while cause I wouldn't believe it was the coils. Cleaned and tested everything I could think off.

Been a while now, all is great, no drops in rpms, good acceleartion and great gas milage.