Ignition system questions

[flyeyes]

I have a slight miss similar to when you have a spark plug or ignition coil pack going bad. I have changed all 6 plugs and 3 of the rear side ignition coils. I'm not 100% positive, but pretty close in thinking that the front side ignition coils are still good. But I'm not positive on how to test them, out...thinking about replacing them as well. Just wanting to make sure there isn't anything else I should be checking before I spend another $350 on parts I don't need.

Experienced input would be extremely helpful. I'm hoping it's not a bigger issue.

Thanks in advance...:redface:

 

[Old Guy]

Do a search on Prime for something called an 'ignition kit' or 'replacement coil packs'. For the later OBDII cars and I think for the earlier cars, Honda offered up the ignition kit which gives you all 6 ignition coils for less than $200. The search should give you the appropriate part # and then go to the on-line parts vendors to find the one with the best price.

As a perk, some vendors use to include replacement spark plugs in the price!

 

[flyeyes]

Thanks, yeah I was informed about the repair kits from a friend today. We are also going to try and swap out the igniter first before moving on to other items. My car is a 92, so it has the 2-wire connectors. So hopefully I can find those from the search on here on Prime.

 

[06_typeS]

Are you experiencing any engine or tcs codes?

 

[Old Guy]

Thanks, yeah I was informed about the repair kits from a friend today. We are also going to try and swap out the igniter first before moving on to other items. My car is a 92, so it has the 2-wire connectors. So hopefully I can find those from the search on here on Prime.

The igniter is just a block of six power transistors controlled by the ECU which are used to switch the current in the individual ignition coils. If one of the power transistors fails, you will definitely know about it as you will have no ignition whatsoever on that cylinder, not a slight misfire. About the only thing you might want to check on the igniter is the grounding and the wiring connections. Bad grounding or a poor connection could cause an intermittent misfire.

 

[OLDMNSX]

There is a service manual in the WIKI: Repairing your NSX, (go to the bottom) Reference Sources; Service Manuals; Electronic Copies of the service manual. or here is the address,
http://www.nsxprime.com/FAQ/Reference/1991_svcman/1991servman.pdf
go to page 23-95 for coil testing procedures.

 

[flyeyes]

So, I purchased 6 new coil packs and also swapped out the igniter with a known working igniter. I am still having issues with a miss while at idle rpms once the engine is warmed up. It is so severe that after trying to drive the car the rpms were bouncing so bad the engine died. Before I take this POS to a shop and blow another $500+ I figured I'd check and see if there were any other items I could verify without spending money on more parts I may not need.:frown:

 

[ftuhy]

Bad injector(s)? What do the individual plugs look like, especially the old ones? Ie. any blacker or cleaner than the others?
On the more serious side, it could be time for a compression test....

 

[06_typeS]

I was having the exact same problems for I put the car back in storage. It is so frustrating not being able to find the cause.

 

[Larry Bastanza]

Do a search on Prime for something called an 'ignition kit' or 'replacement coil packs'. For the later OBDII cars and I think for the earlier cars, Honda offered up the ignition kit which gives you all 6 ignition coils for less than $200. The search should give you the appropriate part # and then go to the on-line parts vendors to find the one with the best price.

As a perk, some vendors use to include replacement spark plugs in the price!

Just FYI, this is NOT applicable for pre-1995 US models. The kit has the three pin coil paks used in OBDII only. The connectors will not match 1991-1994 US models.

Regards,
LarryB

 

[flyeyes]

Just FYI, this is NOT applicable for pre-1995 US models. The kit has the three pin coil paks used in OBDII only. The connectors will not match 1991-1994 US models.

Regards,
LarryB

Correct....

So far I've purchased new ignition coils, plugs, and briefly swapped out the igniter. None of which fixed the issue. Unfortunately it's looking like I'm going to have to take it to a shop, and pray they figure it.

 

[B2FiNiTY]

Please report back your findings!

 

[flyeyes]

So.....here's an update.

I've replaced:
ignition coils (all 6 of them)
spark plugs (all 6 of them)
swapped ignitors
removed the injectors, sent them to RC Engineering to be cleaned and tested. All were 100% in working order.

Preparing to swap out the AEM FIC next, and check the ignition coil wiring, and injector wiring, and possibly a compression test.

So far a little over $1000 spent with NO positive outcome. Kinda disappointing.....

Will post up again as the saga continues.

 

[ftuhy]

My ideas of things to test:
1. fuel pressure
2. compression
3. Ignition switch - usually it just kills the engine, but perhaps it could be intermittant

 

[flyeyes]

Update....

Swapped out my AEM series 1 with another known good unit from another NSX with similar setup here locally. Same issue. Cyl 5 still has a miss.

Next steps will be to check compression on that cylinder, valve springs, and electrical harness as a last ditch effort. Aside from that, the car will probably sit until a compression test can be done. I'm trying to learn how to do that currently....