Bypassing Fuel Pump Relay?

[Daphur280]

So I'm swapping an 83 turbo l28 into my 73 240z for the past year, and have been having this problem ever since I started this swap a year ago. My harness does not have the Fuel Pump Relay Harness (FPRH) that has the relay and plugs into the EFI Harness.

 

I've posted on here several times on the WTB for this piece and have bought 3 seperate harness packages thta failed to include this so I'm no longer going to take the chance of purchasing another harness on here.

 

My problem is I have the B/W wire that comes from the FPRH goin to 12v switched and nothing else from that piece going elsewhere. I notice on the FSM the L/R wire goes to the relay as well as the G wire, now these two on my car are not connected to anything as I do not have a relay to the fuel pump. For now for diagnostic purposes I'm not going to put a relay in until I can figure out what the issue is:

 

Now I have spark coming from the coil, and to the plugs, I have Fuel Pressure, however I have no Injector Pulse, this is my 3rd ECU to have this issue, which leads me to believe I have something not wired. I've combed through the EFI Harness maticulously and the only thing I see absent from being pluged into either 12v, ground, or anything else is the wires coming from the FPRH w/ the exception of the B/W wire which is going to 12v switched.

 

When I previously set up this swap with the FPRit would either leave the Fuel pump running after turning the IGN off, or the last time I set it up (ACCORDING TO ALL AVAILBLE DIAGRAMS HERE AND FSM) it melted the relay, several connectors, as well as fried the ECU. So I have decided that there has to be some way to not include the Fuel Pump Relay with the EFI harness and make the appropriate connections to the wires that connected to the relay.

 

Does anyone know how to set up the efi harness independent of the Fuel Pump Relay Harness???

[loy]

Just reread what you wanted

Are the rest of the wires In figure N connected? Also the harness you have on there now is from what year?

 

You should have power at one pin of each injector when ignition is on.

 

 

You could use a simple relay for the fuel pump in two ways,

 

One way is to have it on whenever ignition is on, These are the numbers on the relay

30->> Fuel Pump+

87->>12 Volt Fused Constant

85->>ground

86->>ignition.

 

The other way is to wire is to wire it using the fuel pump signal from the ecu. This can be seen as Figure N here http://forums.hybridz.org/index.php?/topic/38461-240z-260z-280z-turbo-swap-guide/

30->> Fuel Pump+

87->>12 Volt Fused Constant

85->>ground

86->>Blue with red stripe

Edited May 25, 2010 by loy

[Daphur280]

Ok so I successfully bypassed the Fuel Pump Relay, and wired up that G wire from the FPRH to 12v constant. Still not starting, so I decided to remove the distributor (since I dont have a noid light to test the injectors) and spun it while IGN was on, and all of my injectors were clicking. I dont know if that means they're getting pulse or not, but as of now I have Fuel pressure, spark, and supposedly the injectors are pulsing, but still not starting....

 

Where is my next problem area to check?

[loy]

After you crank the engine check the spark plugs. Are they covered in gas?

Make sure all other sensors are connected.

Check Timing?

[Daphur280]

Yeah that'll be next to check during my troubleshoot, another thing someone recommended is that i check the AFM adjustment, because from my understanding the AFM I have, was adjusted to suit another '83 turbo's tune/set up. So the clock spring [not sure if thats what its called] could be adjusted too tight to allow the "door" to swing open. Also it was explained to me that the position or adjustment of this contributes to the fuel INJ, so perhaps I'm running too lean? I have had a "pop" or 2 when trying to start it...

 

Several sensors: CHTS, several INJ connectors could use a replacement, but from what I can tell they ARE connected.

 

My timing is dead-on, so I don't think it would be that.

Edited May 30, 2010 by Daphur280

[Daphur280]

K, so I've adjusted the hell out of the AFM both loosened and tighten, and it's still not firing up.

 

The spark plugs are not "soaked" in gas, some of them have slight black residue, and when i looked down into the chamber, I noticed there was some residual gas or fluid sitting on top of the pistons (very little like condensation), I think this happened as I was injecting fuel and not sparking which explains why its still there. From what I can tell the plugs are not fouled.

 

I'm at a complete loss and am ready to just scrap the whole project. This whole swap is just beyond me and costing me $1000's, and is causing me to pull my hair out. If I don't get this sorted by June, it'll be to the Cars For Sale section for it.

Edited May 30, 2010 by Daphur280

[Daphur280]

90 views and no one has any advice?

[Zack_532]

Have you checked to see that you have fire out of all of your plugs? Are your points in your distributor cap still making a good clean connection? What about your rotor button? Maybe your losing your fire somewhere, if you're getting gas to the cylinder, but no start.