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Discussion Starter · #1 ·
Recently i have some issues with starting the car (sometime ok sometime takes few cranks) . I am getting very close to solving it i believe but need some help .

I pulled off the Fuel pump relay R20 behind the seat, 5 Pins relay. (click noises on the Relay ie On Off, On off) . already changed new Relay R20 but same behavior.
pin 85 - receive consistent signal from (ECU pin 28 = continuity of fuel pump relay coil) . no issue
pin 86 - I believe this connects to Relay T pin 86 ( Power module and electro injectors) . this i believe is the causing of the issue.

Relay T gets power to pin 86 from the key switch (light/horn), and signal pin 85 from ECU pin 5 = continuity of electron injectors control relay)

The issue that i see is from ECU Pin 5 , after checking directly on ECU Pin 5 (1-6 injectors) its Intermittent voltage/signal. Do you know what will cause the intermittent voltage/Signal at ECU pin 5 = continuity of electron injectors control relay) ? where else should i check ?

btw, some extra info my aftermarket central lock ECU is not working now, and its connected to the same circuit as the key switch to provide power to Relay T pin 86 . it seems to me this might be irrelevant due to Relay T is only receiving voltage/signal from ECU Pin 5. The intermittent voltage/signal came from the ECU .

any thought ? thanks in advance !
 

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97.0 VT Roadster / 08 Gallardo Spyder
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Leslie, I am no electrical expert by any means but I was having some issues and pulled a bunch of relays, swapped them around, replaced some of them with new ones, that sort of thing and all for naught. It turned out it was the most basic of things: a faulty ground wire. Probably also the most common in these Italian cars, too. Good luck.

by the way, how iate the rest of the car projects coming along?
 

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Discussion Starter · #3 · (Edited)
Leslie, I am no electrical expert by any means but I was having some issues and pulled a bunch of relays, swapped them around, replaced some of them with new ones, that sort of thing and all for naught. It turned out it was the most basic of things: a faulty ground wire. Probably also the most common in these Italian cars, too. Good luck.

by the way, how iate the rest of the car projects coming along?
Mark , you are right !! The relay pins are dirty . I cleaned up the relay pins. It starts up every-time and very well now ! I will replace with a new relay .
I should have just done this first step before diagnosing the full wiring circuit .

I have managed to restore the full engine , replaced the burnt clutch to new Kevlar clutch ..I will drive the car for a few months to make sure all good , I will then move to exterior / interior restoration.. this is a looong journey but I have learnt so much about Diablo along the way ! And most importantly I am enjoying it

 
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