INTERMITTENT NO START NA6

Bred · Postby **Bred** » Mon Aug 08, 2016 2:24 pm

Have a slight issue here. Have no idea what else it could be. Fuel pump sometimes has power sometimes doesn't. Is there any common issues that these cars struggle with?

Bred · Postby **Bred** » Mon Aug 08, 2016 2:29 pm

Have tested everything and have narrowed it down to either a dodgy fuel pump relay or an ecu. Was wondering if any of those are a common problem.

BlackLeaf · Postby **BlackLeaf** » Mon Aug 08, 2016 3:27 pm

I'm Brisbane southside and have an ECU if you want to swap it and see if that makes a difference?

StanTheMan · Postby **StanTheMan** » Mon Aug 08, 2016 3:55 pm

Perhaps it would be good to detuct at least 1 part of the 3.
If you have knowlege of your ECU getting flooded. It probably is toast. Open it up & see if there is any obvious signs of it being toast.

like this maybe?

Once you have the ECU deducted from the equation by maybe bolting in a borrowed one or obvious signs of it being toast. You can deduct the pump or Relay. My pump in the past had intermittent issues before it spat the dummy.

My bet it is the pump. That's not to say the ECU or relay can't be toast. I did read somewhere here someone had trouble fitting a later NA6 ECU to an short nose NA6 in the past. I don't recall the exact details. If memory serves me correct it was also a late JDM ECU.

You probably do know you can isolate the pump & relay through the diagnostics box but it needs to be playing up at the time and you need to know the ECU is working.
Hope that helps

93_Clubman · Postby **93_Clubman** » Mon Aug 08, 2016 4:40 pm

While waiting for a spare ECU, check for the blackwire issue inside the top of the fuel tank gauge/pump assembly that affects the fuel pump itself - initially it results in intermittent power to the fuel pump & not-starting - eventually it's gets so bad it won't start at all:
viewtopic.php?f=55&t=46425
Good pic here of the actual issue, given pics links in above are stuffed:
viewtopic.php?f=55&t=70835

Bred · Postby **Bred** » Mon Aug 08, 2016 4:41 pm

Thank you for that. I got it running by a miracle I think. I found the plug on the relay has slightly melted so I think the relay has had enough. I haven't cracked the ecu open to have a look yet but might do that as soon as I can. I just want to get the old girl home. I'm having trouble finding a new relay for it also. I'm just really confused by what it could be. Everything is absolutely fine and it runs awesome and then all of a sudden just won't start. Tested everything and just came to the conclusion that it's either yeah the ecu or the relay.

Bred · Postby **Bred** » Mon Aug 08, 2016 4:43 pm

93_Clubman wrote:While waiting for a spare ECU, check for the blackwire issue inside the top of the fuel tank gauge/pump assembly that affects the fuel pump itself - initially it results in intermittent power to the fuel pump & not-starting - eventually it's gets so bad it won't start at all:
viewtopic.php?f=55&t=46425
Good pic here of the actual issue, given pics links in above are stuffed:
viewtopic.php?f=55&t=70835

I have replaced the wiring for that specific plough and the bench tested to make sure the pump runs and it has. Can the gauge wiring somehow affect the pump at all? I just did not pay attention to the gauge wiring while fixing the pump wiring.

Bred · Postby **Bred** » Mon Aug 08, 2016 4:47 pm

Also I have installed a new pump as i initially thought that was the issue. And it has tricked me and the car ran fine after that for a long time. Now playing up again. So from the pump side everything works. From the top of the pump plug. Its from the pump plug back that I am unsure of. I don't think it would be faulty wiring but rather a module of some sorts of a relay.

93_Clubman · Postby **93_Clubman** » Mon Aug 08, 2016 5:11 pm

Bred wrote:I'm having trouble finding a new relay for it also.

ebay or wrecker are your friends.

Bred wrote:Can the gauge wiring somehow affect the pump at all? I just did not pay attention to the gauge wiring while fixing the pump wiring.

From memory, four prongs in top of tank assembly electrical connector - what eventually happens is that shorting out occurs, so yes it can.

Bred wrote:From the top of the pump plug.

Be very certain it's not this by checking it thoroughly:
viewtopic.php?f=29&t=72105&p=885368&hilit=pump#p885368

Bred wrote:Its from the pump plug back that I am unsure of. I don't think it would be faulty wiring but rather a module of some sorts of a relay.

There are two relays affecting fuel - one is the fuel pump relay under the driver side dash - other is the 'fuel inj' relay in the fuse & relay box in the engine bay. The latter is usually the problem one.

Bred · Postby **Bred** » Mon Aug 08, 2016 5:14 pm

There are two relays affecting fuel - one is the fuel pump relay under the driver side dash - other is the 'fuel inj' relay in the fuse & relay box in the engine bay. The latter is usually the problem one.[/quote]

Where abouts is the second relay located I have no stickers left on any fuse boxes?