[car2n]

Telion like you said if its priming during the ign position is not the pump, by looking in the diagram and with all the checks you already made and knowing also some of the symptoms I know is not one of the related fuses to the main relay and ECU the problem has to be the sensor signal that "tells" the ECU that the engine is running (turning) to hold the output signal to the main relay fuel pump secondary coil,I don't know how the ECU knows if the engine is running but my guess will be the knock or MAP sensor but is just a guess but it won't hurt to check wiring connections to these sensors and posible the fuses going to the main relay:dunno:.

I will look into it some more the sequence is almost the same for the NSX with the difference that NSX has an extra relay for the fuel pump.

 

[Telion]

Ok I am going to upload a vid, and yeah in flash chat (great feature) we were considering it being the ignition switch as part of the issue because that is a common problem that causes you to only have the fuel pump stay on by having to hold the key in the start position. when you release the key it cuts the fuel pump do to a malfunction in the switch (or something related going to or from it)

Battery is also dying now
€

 

[car2n]

It sounds like the ignition switch to me...

Unplug the switch from the fuse box, turn the key to on position and check for continuity between:

White --->Yellow

And then

White ---> Black/Yellow stripe

There should be continuity both ways. Now there is a White/Red stripe wire, don't confuse it with the solid white wire.

Here is the breakdown of what color does what:

Solid White: +12v

White/Red Stripe: Accessories

Yellow: Ignition 2

Black/Yellow Stripe: Ignition 1

Black/White Stripe: Starter

Well I think the ign switch its doing its work since the ign1-2 position "tells" the ECU that fuel pump need to prime for ignition start position(momentary) "tells" ECU to momentary hold the signal to start the engine and other sensor (unknown to me) "tells" the ECU that engine rema ined running and tells the ECU to finally hold the signal so I figured that has to be the unknown sensor or a blown fuse but I believe Telion already did it.

 

[Telion]

That ^ is the missing element what tells the ECU to the engine has started and to keep it on after the key is let go

 

[Telion]

Oh yeah it also threw codes 14 EACV and 42 passenger side Oxygen sensor again.

 

[sap]

Telion like you said if its priming during the ign position is not the pump, by looking in the diagram and with all the checks you already made and knowing also some of the symptoms I know is not one of the related fuses to the main relay and ECU the problem has to be the sensor signal that "tells" the ECU that the engine is running (turning) to hold the output signal to the main relay fuel pump secondary coil,I don't know how the ECU knows if the engine is running but my guess will be the knock or MAP sensor but is just a guess but it won't hurt to check wiring connections to these sensors and posible the fuses going to the main relay:dunno:.

That was my suggestion as well, but I'm also not sure what sensor(s) the ECU uses to determine the car is "running". My guess would be the crank sensor.

I'd feel pretty confident in saying the ignition switch, main relay and (like car2n said) the fuel pump are not likely at this point. It's the exact same circuit for priming the car vs. running the car (with the FLR output from the ECU being what actually controls whether the fuel pump is powered or not).

 

[sap]

Oh yeah it also threw codes 14 EACV and 42 passenger side Oxygen sensor again.

Blown fuse #22 (under dash) would explain the code 42 and the pop you heard (troubleshooting chart for code 42 is on 11-40 in the service manual).

Code 14 troubleshoot is on page 11-74, but it doesn't offer a similar explanation for the pop (which, IIRC, was when both codes started coming up).

 

[Telion]

I will check fuse 22 tomorrow (well tonight) if that was the pop I will be joyed. maybe I will check it now lol.

 

[sap]

I will check fuse 22 tomorrow (well tonight) if that was the pop I will be joyed. maybe I will check it now lol.

Heh, that almost seems like it'd be too easy .

Wish I could help more, but besides looking stuff up in the manual I've been well out of my league for eighty-some pages :lol:.

 

[Telion]

haven't we all lol checked all the fuses they are good (think that's twice now)

 

[car2n]

haven't we all lol checked all the fuses they are good (think that's twice now)

Then it has to be the main relay or the crank sensors i check my manual and crank senses for the crank position for the injectors pulses and also senses RPM for engine running, in the NSX manual shows how to check the MR it looks the same by looking in both disgrams but not sure anyway since you heard something "pop" and it wasn't a fuse then do a test sequence for the main relay and if isn't that check the cranks.

 

[Telion]

main relay has already been tested and verified good.

 

[sr5guy]

You're using the RL intake manifold, right? Are you sure that you didn't plug the wires for the IACV into the air intake or coolant temperature sensor? All three use the same 2-pin round plug. My guess would be that the air intake and IACV are reversed - as the coolant temp would set an instant code. This explains the pop, as the IACV gets alot more power. When you plug it in to one of the temperature sensors it just about shorts the IACV circuit out. Check your wiring, most likely you just fried one of the sensors and that was the source of the pop. Worst case scenario you fried the control circuitry inside the ECU.

-Matt

 

[Telion]

I am glad I have your mind on board on this but nope TII intake manifold and the wires are the same pinout but they are color coded and correct . But keep the ideas coming.

 

[sr5guy]

Well, if you have an IACV code 14 and the car wont stay running... thats definetly related Check and see if you have battery voltage at the eacv with the ignition on (yel/blk wire and engine ground) - that comes directly from the main relay.

-Matt

 

['94'Polymorphic'GS']

a legend CAN run depending on if the solenoid on the IACV is froze in the open position. This happened on another members car. He disconnected the connecter and the car ran however it ran rich, hence why the other code will throw for O2. So your solenoid is blown or the other relay IN the main relay is fried hence the pop.(two mini relays in main relay). You can jump two pins on one of the connectors for the relay to keep the pump on full time to at least run the car.

shit goes wrong on a car that sits for a while. don't sweat it.

 

[Telion]

Ok guys I don't blame you for not following what has been tested because this is becoming a bit drawn out really could even use a separate thread because I am certain it is unrelated to the build but this gets exposure so. . .

But I pulled the connector on the EACV on my wifes car and it started fine then a few seconds later while idling it through a CEL. Now with that same logic I put the main relay in my wifes car and tested it and it fired up fine. so now that I have your great minds up to speed what else could it be.

 

['94'Polymorphic'GS']

check the IAT and the EACV connectors.

 

[Vic Cardenas]

so now that I have your great minds up to speed what else could it be.

Did you change out the fuel injectors? Haha, just kidding.

Did you ever siphon out the old gas and check your timing? It sounds like you got everything except those.

Did you check the functionality of the ignition switch like mentioned before?

 

[sap]

You can jump two pins on one of the connectors for the relay to keep the pump on full time to at least run the car.

This actually seems like a good idea, if you force the pump to run and it idles then you know the ECU is killing the fuel pump. If you force the pump and it still doesn't idle then you can (mostly) ignore the fuel pump end of things.