Help

[Sohcem]

Need serious help to make my 1993 NSX run again. Had starter rebuilt installed no start totally quiet. Checked to see if had power to starter from main lead o.k. small igniter wire no power.
Replaced ignition wire harness, starter turns over car will not fire up? At A total loss of what to do. Any suggestions would be greatly appreciated.

 

[liftnot]

Was it running well b 4 the starter rebuilt? If it was, thats odd. ck for sparks, ck for fuel pressure. Need more back ground info. on the car.

 

[jwmelvin]

Does the fuel pump prime when you turn the key on?

 

[Old Guy]

Check out post #40 in this thread for jwmelvin's excellent trouble shooting flow chart for no-start conditions. I am surprised that he did not link it himself.

http://www.nsxprime.com/forum/showthread.php/198365-Stranded-2000-nsx/page2

 

[robertcope]

You need fuel and spark to start. I would start by checking for fuel pressure, since there's an easily accessed port for that. If you don't have fuel pressure, you start checking that system out... fuses, relays, etc. If you do have fuel pressure, you move on to spark. It's all in the workshop manual.

 

[Sohcem]

Won't Crank

Thanks so much for all the return replys. Sorry for the late reply, been ill. Fuel pump working, changed icm, changed main relay, also put in another key switch harness, just in case. Turns over great
will not fire? Ran fine before starter rebuild? Also checked grounds. Any suggestions? Thanks so much for all your time and efforts.

 

[DocL]

Where in Florida are you located? We have a few good independent NSX mechanics who know the car very well that you can take it to be fixed.

 

[Old Guy]

Try using the service check connector to see if you have any stored error codes in the ECU. A failed cam / crank position sensor would definitely leave you with a no start situation; but, would normally generate an error code.

You said the fuel pump is working. How did you confirm that? Is it going through the 2 second prime cycle when you turn the ignition key to on? If so, that confirms that the main relay is OK, the pump is OK and the ECU is powering up (although the ECU could still be faulty).

I suggest that you check the operation of the injectors and ignition while cranking the engine. An injector test light provides a convenient way of determining if the ECU is firing the injectors. A timing light can be used to check for operation of the ignition. The other less convenient ignition check is to pull a coil and plug and press the ground electrode of the plug against the block and check for spark while the engine is cranking. If you do the plug test, you will want to pull the plug for the fuel injector resistors to prevent fuel delivery on the off chance that the engine does start during the test.

If both the ignition and injectors are non operational, then you need to go through the ECU check procedure in the service manual. If the ignition is dead or the injectors are not operating, then you need to investigate those specific areas.

 

[Sohcem]

Won"t Crank

Thanks for getting back to me. I am In Fort Myers, Fla. Yes the fuel pump is working, could hear the pump, also loosen plug on passenger side and fuel pressure extreme!
If doing the test for the coil pack, injector and spark plug, where do I find the plug to bypass the injectors? Again thanks so much for your input.

 

[Old Guy]

Thanks for getting back to me. I am In Fort Myers, Fla. Yes the fuel pump is working, could hear the pump, also loosen plug on passenger side and fuel pressure extreme!
If doing the test for the coil pack, injector and spark plug, where do I find the plug to bypass the injectors? Again thanks so much for your input.

On the early cars, the fuel injector resistors are a boxy arrangement mounted on the passenger side of the engine compartment just back of where the engine compartment cooling fan would be. The injector resistor pack is connected to the wiring harness with a single 8 pin connector (only 7 of the pins are used). You are not by-passing the injectors. By disconnecting the injector resistor connector you are guaranteeing that the engine will not start when you are doing the coil / plug test because the injectors are now disconnected. If you go to the NSX Wiki you can find links to .pdf versions of the service manual. Get the version for the early cars, not the later cars which do not have fuel injection resistors. In the fuel system section of the manual there is a diagram showing the location of the injector resistors.

When using the injector test lights to test the injectors, do not disconnect the injector resistors. The injectors need to be receiving power through the resistors is order to use the test lights to confirm that they are getting the signals from the ECU.

Since the failure seems to have coincided with the starter R&R, I would have a look around that area to see if anything was dislodged during the R&R. I am assuming that the starter R&R from below the engine in which case its not obvious what could have been disturbed. If R&R was attempted from above the engine (is that even possible?) there would be a lot of stuff in the way. I would check the connections to the control box as a start. However, if something critical was disconnected, that would normally generate an error code in the ECU.

You have confirmed that you have fuel in the fuel rail so you have addressed the more common / easy to diagnose failures. Short of finding something disconnected, everything gets more complicated from this point forward. Unless you have the time and the tools, I might be inclined to follow [MENTION=3821]DocL[/MENTION] 's advice.