Coil Pack differences

T

TitaniumVtec

Experienced Member
Joined
16 June 2000
Messages
835
Location
30 miles from The Dragon. On the TN side of cours
Does anyone know the differences between the FR and RR coil packs? I ask because I am in the process of trouble shooting a hesitation problem under light acceleration, which I hope to solve with new packs. Since I don't currently have any spares, and most of the ones I have found for sale are for FR. I just thought I would ask what the differences are.

I had both an FR and RR pack in my hands last night, and I really did not see a visual difference between them. I didn't look too hard to see if the connectors were different, or if the bolt hole locations were off. Just a quick comparison that's all. I have owned other cars that used coil packs, and swapping them around to solve a problem was common, regardless of location. I did ohm test all of them and they were exactly the same @ 1.0. I know this doesn't prove much but it was worth a shot.

If anyone can shed some light I'd appreciate it. I did some searching and only found one thread that made reference to keeping coil packs on their right sides. The manual also says to keep them together, but not much info as to why. Can you run 6 similar packs for testing purposes??

Here is a picture of one my RR packs. Two of them look very similar regarding the rust. You can almost see that the rust is going inside. I hope this is the culprit Anyone have similar experiences with rusty coil packs??
DSCN7877.JPG


Thanks in advance,
James
 
I have looked for you and see no difference, they also do the same job, transforming the signal of the ECU to high voltage for the spark plug.I cannot think of anything why they should be diferent.....:confused:

The ones i have here also have some rust on the rear ones, would a deffective coil give the most problems when cold starting the engine???

What is your problem?
 
My problem is as follows:

When I'm accelerating under light throttle, the cars starts to bog/hesitate until I press the pedal a little more. Then it pops back to life and speeds off. Even while cruising at speed, I sometimes feel a light backand forth surging.

I have done some searching and it sounds similar to what others have experienced with a bad/failing coil pack(s). It has been getting progressively worse over a period of 2-3 months

I figured I would check the simple swap/replace items before further diagnosis. The CEL comes on every once in a while also. I tried pulling codes and the number of flashes did not correspond to the chart. I will try it again and present my findings.
 
I am going through the same problem right now. I think I’ve narrowed it down to the EGR. Try removing the vacuum line from the EGR and go out for a test drive. If it feels better then I think the problem is in the EGR (obviously you’ll get a CEL). I’m awaiting my new EGR and let you know if it fixes the problem.

.02
DanO
 
Cold air and fuel mix (as in cold engine) does ignite vary badly, this is why the factory's ivented the chocke system.It makes the engine much richer on fuel.This also contributes to not easy ignition.

Al this require more energy from the spark plug, this must be delivered by the coil pack.If the coil is just working than in cold condition the most problems.

When accalerating also a rich mixture is used for optimal performance.

Looks like you are right :coil pack gone bad
 
Dan0 - Good luck buddy! I read your problem on other threads and wondered if you had found your problem. I will also try the EGR trick. Can hurt I guess.

Cees-Jan - I sure hope it's something simple like coil pack. trouble shooting can some times be a real pain in the rear.

I just purchased 3 FF coil packs from pixelhause for $50. My RR packs are the ones with rust, but I'm just hoping I can replace them with 3 FF packs for testing purposes. If it all clears up then I might replace with the correct (RR) ones. I will keep everyone posted on my progress. Hopefully they will arrive by early next week.
 
Cees-Jan said:
Cold air and fuel mix (as in cold engine) does ignite vary badly, this is why the factory's ivented the chocke system.It makes the engine much richer on fuel.This also contributes to not easy ignition.

Al this require more energy from the spark plug, this must be delivered by the coil pack.If the coil is just working than in cold condition the most problems.

When accalerating also a rich mixture is used for optimal performance.

Looks like you are right :coil pack gone bad
Click to expand...


Huh? Cold air ignites much better because it is more dense with oxygen.

Anyways...it sounds like your problem may be related to throttle positions and vacuum.

Things I would check would be MAP sensor reads, TPS voltages and vacuum connections. You map sensor may be on it's way out and not being able to differentiate various pressure levels, responding to WOT mostly. your TPS voltage could also be off. You can test the levels at various throttle positions
 
Cold air contains more oxigen, correct. Cold air has a higher resistance to make a spark go from the plug.No spark = no start.

If at cold start more air is a good thing (thats what you say) then press the accalerator to the floor and give it oxigen !!!(this whil not work)
 
I think you are confusing cold air, with a cold engine. Are you saying when you start your car the air is cold, and then warms up?

I'll be interested to know of the coil packs are the cause of this problem. I have the same amount of rust, but I smeared some electrical contact grease over the metal parts of the coils. Seems to be better now.
 
Are your rubber seals still okay? Mine was bad and my stupid friend threw it away without replacing it with the new one. Water gets in and my engine start bogging under heavy rain. Sounds something like Subaru. My coil packs got rusted because of that. I plan to replace it once I got the money.:(
 
j14nsx said:
I'll be interested to know of the coil packs are the cause of this problem. I have the same amount of rust, but I smeared some electrical contact grease over the metal parts of the coils. Seems to be better now.
Click to expand...
I am going to put the car back together until the coils arrive next week. I will clean up the rust and apply electrical grease to see if I notice any changes.

Jin1976 said:
Are your rubber seals still okay? Mine was bad and my stupid friend threw it away without replacing it with the new one. Water gets in and my engine start bogging under heavy rain. Sounds something like Subaru. My coil packs got rusted because of that. I plan to replace it once I got the money.:(
Click to expand...

My seals look pretty good, but I'm sure over time a little water can sneak in. It wouldn't take much to start the rusting process IMO.

Your Subaru reference is exactly what my car sounds like when my problem pops up. Since the rear packs are below the air inlet on the edge of the trunk, it's very possible that water is/was getting to the packs from rain and washings. I never realized that till now.

I sure hope this is my problem. I hate chasing down electrical gremlins. Without the correct tools, some things can be damn near impossible.
 
j14nsx said:
I think you are confusing cold air, with a cold engine. Are you saying when you start your car the air is cold, and then warms up?

No I am not confused I am just trying to explain that a spark travels more difficult trough (relativly) cold air.(Think of thunder and lightning which occur more often on a hot moisty summer day and hardly ever in winter)
This is why all older cars use preheated air when in cold conditions.Modern (computerized ) engines can compensate this effect by changing the A/F mixture.....

Because you have cleand the rusty surface of the coil packs you are giving them more electric power (better connection with battery negative) and thus more spark power.

If there is a lot of rust inside the coil pack then it is loosing magnetic field, this will result in a lower output voltage(lower spark energy)

Also a tip to make a spark go easier at your sparkplugs is to adjust the distance from 1.1 mm to 0.7 mm by gently (!) hammering it.(Have to take them out)

Maybe you want to try connecting three electric wires to the battery neg. connection on the valve cover and to each coil pack.
(Cupper has lower resistance than alu/magnesium valve cover)
Click to expand...
 
Last edited:
I have an other thing, are you using an after marked (cold air ram or whatever) intake air filter or the original box and filter???

This can effect the problem, when accalerating the ecu first goes to a pre pro grammed (PGMFI) air/fuel ratio, because of the filter there is too much air (compared to factory conditions) coming in the engine thus making the mixture lean.

After this accelerating the O2 signal will make the CPU correct for this, but however too late...... it already hikked in the first instand.

(This problem is very common on the CRX engine at low RPM)
 
I am running an after market air filter from Injen. I added this because I added NOS to the car. I like the simple tube design which allows for the fogger to easily be installed between the filter and throttle body. I am not going to use the NOS until I figure out why my car is running the way that it is.

I will put my stock air box back on for comparison purposes. I never really thought about that being a potential problem as so many others are using them. Now that I think about it, this problem did kinf of surface around the time I removed the stock air box.

One last thing. I pulled codes today and got a 43. "Front fuel system" I think they call it? Looked up the meaning of it and it could be an 02 sensor, injector, injector resistor, fuel filter, fuel pump, etc... Figures it would be the most vague error possible.

I really appreciate all you advice and suggestions.

James
 
I believe I have fixed my problem.

After a comment made by Cess-Jan, I decided to put my stock air box back on. What would you know, the hesitation went away. I couldn't believe it!!! Not like it was terrible before, but the car is back to its smooth old self. I hope this is not a fluke and the problem will return tomorrow. But I did drive the car for about 30 miles this evening and it was smooth all over. I could not get it to happen in any gear at any speed. Before it was easy to reproduce. Just try to drive away from a light under light acceleration. Then slowly press harder until the hesitation went away and the car jumps (like a tug-o-war game when the other team suddenly lets go of the rope) ahead.

Thanks to all that responded. I will post again the next time I drive it to double check that all is well.
 
Now you know that your car is running lean (when accarating) and you have codes with fuel presure lines .

Maybe you have a fuel filter that needs to be replaced, check your fuel pressure and (possible with aftermarket FPRegulator)set it to the top of factory settings(or try even a bit higher), maybe now this will compensate for the aftermarket air filter.

I have never tried this but it should work while the ECU expects the fuel presurre to be spec and it can only influence the injectors as I explained before (PGMFI system).

:)
 
Just wanted to post an update. Back on 6/5 I thought I had solved my hesitation problem when I switched my air box back to stock. That only lasted a few hours and the problem came back. Since then, I've been reading the issues other NSX owners here have been having, trying to learn which direction to turn next.

This past Saturday I decided to change my oil. While under the car I looked at the O2 sensors (car has headers) and basically could tell that one was original (OEM) and one was NGK (NTK). I noticed that all of the wires were zip tied to the chassis in various locations and that all appeared to be fine. I changed the oil filter from the current shortly style to the original longer type. In the process I had a bitch of a time getting the filter wrench off the longer filter after I gently 'snugged' it up. All the wires from the O2 sensor are directly under my filter so I was fighting the original limited space with the addition of the O2 wires. Long story short, I got the filter on and put the car back on the ground.

Started her up and she idled just fine as always. Took it for a ride and it was much, much smoother right from the get go. My worse time with this car is when it is cold and I am just trying to pick up speed at a very slow and gradual pace. That is when it sounds like a Subaru on 4 cylinders. Car ran fine. Drove it later that night after it had cooled back off and the same thing; drove great. Went on a 4 hour ride yesterday with BladesNSX and not once did the problem surface.

I don't know what to say other than the problem is gone for now. Maybe there was a short in one of the wires? Maybe I don't have a clue as to what changed!! But the car is working again, so I am leaning more and more towards O2 sensors that previously. I did get a CEL code 43 (front fuel supply) two or three times over a period of 4 months, but that has not surfaced in a while.

I will keep this thing updated if anything else changes. But for now, I am happy again with my X.

James
 
Cees-Jan said:
Good news that al is well, Why did you not also replace the fuel filter while your hands where still dirty??:) :confused:
Click to expand...
Good question!! My hands are always dirty it seems when it comes to cars. That will be next week's project. ha, ha Thanks for all your advice again Cees-jan. We need more members like you around here for sure!
 
But the car is working again, so I am leaning more and more towards O2 sensors that previously. I did get a CEL code 43 (front fuel supply) two or three times over a period of 4 months, but that has not surfaced in a while.


James [/B]
Click to expand...


Is the NGK the front sensor?(towards the passengercompartment)
I would recomend that you dump that NGK O2 sensor! I had a "code 43" when I took the NSX I bought to an NSX specialist to have it checked out. He saw that it had an NGK sensor in it and he told me I needed to put a Denso(OEM style ) back in it ASAP. He told me that he's seen the NGK's do strange things to NSX's. Told me about one guy who had to replace his ECU($1100) because of and NGK that had bad wiring.
Hope this helps.
Gary.
 

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