306 fuel relay test.

david77

New member
Tadpole
Joined
Dec 28, 2012
Messages
14
Location
Goolwa SA
Hi I have a 306 Rallye with a RFV series motor. It has a crank wont start issue. The fuel pump plug has no voltage. if i supply power to the pump it runs and the engine fires. I have swapped the relay for another but they could both well be dodgy. How do i check the continuity of the wire from the pump to the relay? I have power to pin number 14. I have tried bridging pins 5 and 8 and the fuel pump didnt run - are these the right ones? Also, I am not getting any power to the fuel pump and o2 sensor fuses to the under bonnet fuse box near the battery when the ignition is turned on. I am thinking that the fuse would be before the relay, is this also wrong of me? Is it possible that just the fuel circuit is not getting power from the ignition switch or something like that. Any help would be appreciated. Cheers David.
 
Did you test the relay itself (the coil) has power? Did you test the relay on the bench?

The wire you mention (pump to relay) can be checked separately quite easily with a continuity tester I imagine.

Are those pin numbers you mention the relay pins? To figure out which pin does what you need at least a continuity tester. Or a power source and a globe or some such. Continuity tester should identify the coil terminals (pins), and NO/NC pins, then apply voltage to coil and listen for a click. Test NO pins to see when the relay clicks they actually conduct.
 
Thanks for the reply schlitzaugen, the pin numbers are relay pin numbers. I have no idea what all the pins refer to as i cant get a wiring diagram for my car. I understand that pin number 14 is the power in and I read on a 206 forum that pin number 8 is the fuel pump. I have not bench tested the relay. It seems like a bit of a common problem, so i thought someone might know straight off. I have ordered a new relay and will get back with how i get on.
 
I think it is worth checking the relay you have because if that checks out then it's not it and a new one won't do much. Test on the bench like I explained above and you'll know in one minute what's what.
 
I have an 306 S16 RFY and to test the fuel pump you bridge pin 9 and 11 to give it 12v (the big brown relay). My engine uses bosch motronic 3.2 so not sure if it's the same. I very much doubt it would be continuity. I can't remember the details, but when you turn the key to ignition you should hear two distinct clicks from the relay. On the S16 I think it checks the crank angle sensor and cam sensor before supplying fuel/spark.
 
Just a quick note to say I am up and running again. I replaced the relay, and got a voltage of about 10.8v when cranking - no prime. I had the battery load tested, it failed so i got a new one. Eventually swapped the fuel pump and away it went. I don't really want to know if i actually needed the relay or battery, just happy to be mobile again. I does prime but for about one second max. I should of started with the fuel pump first maybe I guess, but it was making a noise with a motor bike battery wired directly to it. Thanks for you help, it is appreciated. Cheers David.
 
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