Need help installing: A.S. Motorsports Ignition upgrade kit

[Toddp]

Hi guys I wanted to replace my OEM coil pack setup on my 91 nsx so I bought this kit however I think I installed them the wrong way. I figured it would be easy to put in which it was but I missed something along the way. Originally when I was done the car had no spark, and than I played around with the orientation of the male connectors plugging into the oem coil pack harness and that seemed to make the car almost turn over but far from running properly.

Does this kit work with a 1991 nsx ecu?

I scanned in the instruction sheet, and highlighted the section that I may have done incorrectly.
-Once you delete the oem icm it leaves a plug left undone is that plug to remain undone or does something plug into it? (see pic #1 )
-While the new A.S. motorsports harness connects to the older nsx icm plug (pic #1 with my hand on it)
-When the instructions ask to "install the red connectors near the coils into the existing coil connectors from the oil ignition" does that mean they are placed into the original coil pack plugs? (see pic #2 )
-A.S. Motorsports did specify those connectors go into the positive side of the oem harness but I am wondering which side is the positive and the negative.

SCAN0117 by t0ddp, on Flickr

Pic #1
IMG_2819 by t0ddp, on Flickr

Pic #2
IMG_2820 by t0ddp, on Flickr

I did reach out to them about the install, and got one email back which was helpful although I have not herd back since and figured I would ask Prime to see if you guys could help me out?

 

[Old Guy]

The Bosch coils use logic level triggering. They probably have 4 connector pins which will be
- steady +12v supply
- steady ground connection
- logic level trigger signal (typically 5 volts)
- a misfire monitor which won't be used.

If the coil has 3 pins then it likely does not have a misfire monitoring circuit
If the coil has 5 pins then it likely has separate grounds for the trigger signal and the primary coil current.

The connector that went to the OEM Honda coils had two pins. One pin will have a steady +12 v (switched by the ignition switch) which is the +12 v supply to the coil. On all 6 coil connectors this will be a black/yellow wire. The other wire in each connector will be white / different color for each coil. This white / xxx wire goes to your now missing ignitor. Once the OEM ignitor has been removed, that white/xxx wire in each connector goes nowhere and is presumably unused. Since the Bosch coils need a steady +12v, I am guessing that AS wants you to get this for each coil by plugging that connector with the red wire into the original coil pack connector and it should be plugged into the pin connected to the black/yellow wire. You should be able to see the wire color on the plug; but, if you want to be super sure, turn the ignition switch to on and<script src="https://adservice.google.ca/adsid/integrator.sync.js?domain=www.nsxprime.com"></script><script>processGoogleTokenSync({"newToken":"FBS"},5);</script> then measure (to ground) the voltage on the coil plug connector. One should be +12v and the other should have nothing.

That connector on the rear side of the throttle body that used to be connected to the ignitor should be an 8 pin connector. It should have the 6 white/xxx wires in it that went to the 6 coils plus 2 grounds. If so that connector is now unused. The AS wiring harness should have a 6 pin connector that connects into the 6 pin connector that used to plug into the ignitor. This connector picks up the trigger signals from the ECU. The AS harness should have some ground connection lugs on it. Make sure that you have an excellent ground connection otherwise you are going to have flakey operation.

Make sure that you have not burnt fuse #13 in the main fuse box. This fuse supplies the coils and the ECU. If the fuse has popped, then carefully examine the OEM harness that went to the OEM coils. Your car is 27 years old. It would not be unreasonable that a wiring problem might have shown up while you were moving 27 year old wires around during the install.

Its unlikely that you have damaged the Bosch coils. However, if you did damage the coil(s), Denso branded replacements for the R8 V10 are available from Rock Auto for less than $20. No point in springing the $ for Bosch branded coils if you are still in the test and fry mode.

Again, it is unlikely that you have damaged anything. If you can't get the engine to fire up with the AS coil kit, I would re install the original coils and ignitor and test to make sure that the engine fires up on the OEM stuff. That would then point the finger directly at a problem with AS kit. Before you do this, when you say that the car almost runs, pull one of the Bosch coils out with the sparkplug connected. Have somebody crank the engine while you hold the spark plug ground electrode against the engine block. If you get a spark and the engine is not running, then you may have bigger problems associated with ignition timing or incorrect dwell. You would need to take that problem up with AS.

 

[B2FiNiTY]

Im interested in how this performs. please update us once you figure it out. Thanks

 

[A.S. Motorsport]

Hi!
We where closed for holidays hence the slow response, I'll mail you my direct number so we can troubleshoot it over the phone

 

[Toddp]

Hi guys thanks for getting back to me I've been away from the computer and car for about a week. I originally bought this to replace my OEM coil setup, the car had a hesitation on the originals so I took them out and cleaned the coils up and it went away. So I had an issue with the coils but not a big issue, for the time being I put it back the the originals just so I can drive the car.

I took all the info in and tried it out and had a similar end result when I tried to start the car before. It will crank over only for a quarter of a second and thats it. Thats with me disconnecting the ICM, while grounding the old ICM harness, and both new A.S. grounds as well, connecting the coils in the correct firing order as labeled on the connectors, and plugging in the A.S. male connectors into the old OEM coil plugs. I checked out the old coil plugs and I placed them into the side which gets constant power confirmed by a test light.


Here's the firing order I am going off of....
Rear of car
1 2 3
4 5 6
Front of car.

I'm going to do my best to work it out, and send A.S. another email now that I am back to the car and will update the thread to help people out in the future.

 

[jimminh]

Hi guys thanks for getting back to me I've been away from the computer and car for about a week. I originally bought this to replace my OEM coil setup, the car had a hesitation on the originals so I took them out and cleaned the coils up and it went away. So I had an issue with the coils but not a big issue, for the time being I put it back the the originals just so I can drive the car.

I took all the info in and tried it out and had a similar end result when I tried to start the car before. It will crank over only for a quarter of a second and thats it. Thats with me disconnecting the ICM, while grounding the old ICM harness, and both new A.S. grounds as well, connecting the coils in the correct firing order as labeled on the connectors, and plugging in the A.S. male connectors into the old OEM coil plugs. I checked out the old coil plugs and I placed them into the side which gets constant power confirmed by a test light.


Here's the firing order I am going off of....
Rear of car
1 2 3
4 5 6
Front of car.

I'm going to do my best to work it out, and send A.S. another email now that I am back to the car and will update the thread to help people out in the future.

just to verify that you know the firing order is 1 4 2 5 3 6... 123/456 etc is the proper identification of the cylinders per bank....looking at the engine from the right fender... but is not the firing order..

 

[Old Guy]

Do you have access to an inductive pick up timing light? If so, with one of those COP adapters you could get an idea as to whether your ignition timing is even in the ball park during cranking.

Also, do the spark plug against the block test. If the spark is really weak, then the NSX OEM ECU dwell may not be working for the Bosch coils.

The fact that the car runs fine with the OEM ignition arrangement says that the problem is not with the car. Perhaps time to have a more pressing chat with the AS guys.

 

[Toddp]

Hey guys forgot to conclude this.
Yes I stand corrected that what I had mentioned is the cylinder order not the firing order. So after talking with A.S. we were able to track down that the previous owner had this coil kit built for a forced induction stand alone setup, not a stock car like mine. That may have a part in why the car will not run on the coils, but run on the stock stuff. They mentioned there is a difference between a stock coil kit, and a stand alone kit that can have a effect on how the car runs. So I am going to cut my losses and give up on the coils for now, as I did buy them used off this forum. I will say A.S. was very helpful especially given the fact that I did not purchase directly through them and they did their best to stand behind their product which was bought second hand.

 

[docjohn]

thanks for F/U ,,AS has been coming to our nsxpo for some years now and does a good job of service being so far away.Buying mods second hand can present issues.