My NSX is sick... please help

[NSXRguy]

i drove the car fine yesterday afternoon just fine. no problems at all. now that night, my nsx is having trouble idling when started. after it cranks, it wants to die, but it stays on. it sounds like a muscle car, and smells like its running rich also. when i blip the gas during idle, the rpms drop and it stalls/almost stalls. my tcs light also went on.

had this same problem about 1-2 weeks ago. tried starting it the next morning, it was fine.

i checked the codes and theyre as follows

p1201
p1202
p1203
p1204
p1205
p1206
p1300
p1399 (pd)

now, im getting these same exact codes. according to nsx wiki, they are misfiring codes. could it be the coil packs? im not sure the last time they were changed, if ever by the previous owner.

if its not the coil packs, what else could it be? the plugs are basically brand new < 3000miles. compression test / leak down test are fine done by larry b late last year.

heres a couple videos showing the problem





another thing is that the car is smoking a lot more than usual. im running catless, and it smells really rich in the rear. maybe the fuel not being burned off???

i was reading some threads on here. whats the chances that im burning valves by misfiring? the longest that i let the car idled for was maybe 1-2 minutes. i did not drive it.

thanks for the time.

 

[DRIFTER]

Check and clean the throttle body some of time it gets gummed up with dirt and grease I had idling issues with my car and this solved the problem.

 

[NSXRguy]

drifter, did you throw codes?

 

[enkrypt3d]

Check and clean the throttle body some of time it gets gummed up with dirt and grease I had idling issues with my car and this solved the problem.

+1! Clean the crap out of the Throttle body and clean or replace the air filter...

I'm not sure why u are getting so many different trouble codes..

I have never had a CEL with a dirty TB though... it only idles rough when I know its ready to be cleaned again.

EDIT: Yes you should replace all your coils and seals along with the spark plugs... this will rule out any misfiring issues.

 

[NSXRguy]

i recently cleaned out my air filter so its not that

 

[enkrypt3d]

i recently cleaned out my air filter so its not that

well you should always clean the filter and the throttle body while you're in there... takes 5 minutes.

 

[s14_tat]

did you check all the vacuum hoses to make sure your not having any leaks in the intake tract or the seal between the intake manifold and the super charger? that might cause the car to run rich which might cause a misfire, or it could be a bad cam or crank sensor. just because the codes are saying its misfiring does not mean that is the cause of the problem. its very highly unlikely for all 6 coils to go bad all at the same time.

 

[Larry Bastanza]

Ryan,

Empty your PM box

Regards,
LarryB

 

[NSXRguy]

box empty

 

[aluminiumdream]

I'm new here and i don't own an NSX yet but have a lot of experience with misfires. I will say that it is most likely the coil. Usually when the car runs right one day and not the other its an electrical malfunction. I don't think its a vacuum problem but i would check over everything. But if it smells rich out the back and engine runs rough it is most likely the coil. Its too bad you don't have cats because glowing cats usually mean unburnt gas is igniting inside, therefore bad coil or plug.

 

[NSXRguy]

so whats the chances im burning valves??? good chance of bad???

 

[DRIFTER]

so whats the chances im burning valves??? good chance of bad???

I don’t think you are going to burn the valves, but I would keep it out of boost until you get it running right.

Did you talk to Larry B? He will know the exact problem and has worked on numerous CT SC NSXs.

He is good like that :smile:

 

[Arfiman]

If the above suggestions don't work (though I hope they do!) try and check the main relay.

I had all sort of funny issues before it was replaced - high idling, rpm drops, not starting up properly - almost dying when trying to start etc. and then fine the next day!

It was all because of that stupid relay!

Good luck in either case!

 

[NSXRguy]

which one is the main relay? excuse my ignorance :biggrin:

 

[rsevo6]

I had similar problem with my very low mileage '98 with whipple CTSC.

Suddenly it started throwing check engine light and several seconds later TCS light, running on 5 cil, sometimes running OK again. After this happening several times, it was running on 5 cil all the time, check engine and TCS on, smelling with gas.

Reading code gave 1304 misfire cil 4.

Checked just about everything, nothing could be found. Finally got the advice from a fellow NSX owner to try another ignition module.

I did and the problem was gone: defective ignition module.

Some time later I spoke by phone with Shad at Driving Ambitions on another topic and told him about the igniter problem, he then told me he had seen this happen before on other NSX-s

So I would advise you to try another Igniter!!!

You are lucky that you have the newer CTSC where the igniter is in plain view and can easily be changed, with my whipple version it is inbetween the supercharger and the intake manifold, so had to lift the supercharger to get to it.

 

[NSXRguy]

i have 6 new coil packs on the way. ill try those.

if that doesnt help, ill check out the ignition module

btw, is the ignition module the "box" in the middle of the picture? below the T for the vacuum lines?

 

[rsevo6]

i have 6 new coil packs on the way. ill try those.

if that doesnt help, ill check out the ignition module

btw, is the ignition module the "box" in the middle of the picture? below the T for the vacuum lines?

I tried exchanging the #4 and #5 coils (as #4 was my engine code) first, but didn't do anything.
Changing the igniter made the change, and as it turned out is a known problem too.

Yes, it is the black box with two big connectors just under the T-vacuumlines, very easily accessable you lucky ba#@rd:wink:

It is the same part number on ALL NSX (3.0 and 3.2), so if you have a friend with NSX somewhere, it will be a very easy 5 min exchange try-out to find out for sure.

I had to lift the supercharger to get to it, as hidden under the whipple charger on my car:frown:
Let us know.

 

[ScienceofSpeed]

The codes you are getting are misfire detection on each of the cylinders and a general random misfire detection code. This likely means that it a system that affects the engine in general rather than an individual specific part like the coils. Check your fuel pressure first to rule out the fuel system. Then, check ignition related systems that affect the engine in general such as the igniter (located on top of the inlet manifold) and ground points (specifically the ground point on the manifold, the main ground lugs, and the ground point for the ECU).

Cheers,
-- Chris

 

[LJSB]

(specifically the ground point on the manifold, the main ground lugs, and the ground point for the ECU).

Yep, +1

 

[NSXRguy]

heres an update on my dilemma

dave (winreboot) was kind enough to pass by and let me try out his ignition module, did not fix the problem

i changed all of my coil packs into brand new oem ones, did not fix the problem

i changed all of my spark plugs into oem honda pfr7g11-s, did not fix the problem

after letting the car "idle" for around 20 seconds, i check 1 of the plugs and its starting to blacken again, car is running very rich

what is the possibility that it can be a timing belt problem? where exactly are the "important" ground points i should check out? what else controlling the ignition could cause the misfire? what about the o2 sensors?

please help!!!

 

[syam]

i'll offer a few suggestions but do not have experience with F/I nsx's.

the last time you drove it (without symptoms) how were you driving? how did the car perform? (i doubt you could jump a tooth on the timing belt though)
what ecu are you using for the CTSC? the comptech solution or a standalone?

i would assume the misfiring issues are caused by the car running very rich. fouling plugs quickly would mean running very rich, that could be leading to your misfires. have any other parts of the fuel system been changed/upgraded recently?
any chance you can swap/try other fuel injectors?
what about the fuel pump?
have you checked your fuel pressure? (this would probably be the easiest and can point in the problem direction)
are there any chances of a bad tank of fuel?

are all other electrical systems in the car working correctly? eg. lights, stereo, windows, switches, etc...to rule out any electrical problems.

i hope this helps. get that thing back on the road! the weather's just starting to turn nice here in jersey.


more:

here's a link to your other thread: http://www.nsxprime.com/forums/showthread.php?t=120267
jakdar also pointed out inspecting the fuel system...i think this is the system to check now that you've ruled out most of the components of the spark/ignition system.
good luck.

 

[NSXRguy]

can somebody elaborate more on the bad gas? how does a bad tank of gas cause me to run so rich and foul my plugs. i know i filled up with SHELL premium

i *think* i filled up when the station was being refilled.......

i did not do any changes to the car recently. its using the rising fuel pressure regulator which comes with the comptech kit. its still on the oem ecu

i have not checked my fuel pressure yet, but i do have a gauge coming. maybe ill just swap with the one in my civic.

as far as im aware, all my electrical components are working.

 

[davidf]

It is a very good rule of thumb "not" to fill up will a tanker is dropping gas. Everything that has settled at the bottom is stirred around until it can settle again. While stations are required to use filters, you just never know. I once found out a local station was using dummy filters to save money.

 

[NSXRguy]

can bad gas cause plug fouling?

 

[syam]

bad gas can cause erradic idles and poor performance, but usually will not cause the spark plugs to foul and/or cause engine misfires.

i would look through the fuel system as jakdar pointed out.

first, the fuel pump, then the comptech rising rate regulator, then the fuel injectors.