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vnss355vyssLSA

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VN SS 355 VY SS LSA UTE
Hi everyone, didn’t know if I should post in the VN-VP section or on here but I’ll give it a shot...

So I’ve recently purchased a 1990 s2 VN SS 355 after not having one for about 10 years. So basically the car won’t start, doesn’t have power to the pump, and no spark. I thought I’d start with getting the fuel pump priming before figuring out the spark issue.

Little info incase it’s relative:
-Battery relocated to the boot.
-Ignition module relocated to passenger footwell
-Loom from underbonnet fuse panel extended and relocated through body to clean up engine bay
- Had a microtech ECU, I have removed it and the loom that was spliced in by previous owner and restored original loom and ECU..
-355 with power torque dual plane manifold and moroso 4barrel throttle body..

Where I’m at:
I have tested the fuel pump by running power straight from the battery in the boot to the purple wire of the fuel pump that goes through the boot floor and the pump runs fine..

I’ve replaced the fuses with brand new units. (under bonnet and dash)

I’ve tried swapping the relays around

I’ve ran a diagnostics on the CPU by bridging the two relevant wires in the diagnostic plug and the code I get is “system ok” (obviously wrong)

The car doesn’t seem to have the anti-theft key switch in the door jam or in the glove box which I thought it would bring a series 2 (although non-power pack)? So I went to feed power to the pink wire (A6) but it already had 12v running through it.

I initialy had 12v running from A1 to the fuel pump relay this morning but I checked it again this afternoon and didn’t?

I’ve tested the relay seat for the fuel pump and the top and the left terminals have power but the right and the bottom didn’t have earth? I traced the the right which from memory was the green wire with white which ran back through the firewall to A1 ignition on the ECU. The other wire (bottom and purple I think) went through the firewall on the drivers side to near the under dash fuse panel (maybe the plug that carried the fuel pump wires).

I bridged out the oil pressure switch plug and the fuel pump starts priming, although I burnt my finger pulling the paper clip out of the plug (was red hot)

So basically I think I should start with getting power to the fuel pump first before diagnosing my spark issue but i could be wrong. I don’t know if my ECU is cactus or if it sounds like a grounding/earth issue or possible wiring problem..

Any help would be much appreciated as I’m currently stuck, been too long since I was a VN wiz.. i can post photos if required to show what I’m dealing with, I also have a good multimeter and test lamp and good mechanical knowledge and decent electrical if that helps.. thanks again
 

delcowizzid

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You should get spark even without the ecu plugged in check for key on power at the coil and module and injectors.the fuel pump relay is the only relay the ecu sends 12v out to all the others fans etc are all earthed by the ecu.the relays for ignition and injectors are all driven direct from the ignition switch
 

vnss355vyssLSA

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ok thanks, just to be sure when checking the 12v at the module, where should i be placing my multimeter probes? and when checking for 12v at the injectors where should i be placing the probes? and in regards to my fuel pump relay, does that sound right, the way i stated it was powered/earthed. thanks
 

delcowizzid

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Check at the coil positive if it has power the module should have power.also make sure the ignition module is bolted to a good earth
 
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