marklemac

Hi,

Had a very strange problem yesterday in that I started the car, reversed it, stalled it as per usual due to the twin plate clutch and not enough revs.

Then the car wouldn't start. I couldn't here the fuel pump prime.

I checked everything over and in the end called the RAC. The chap came out and we checked everything over, fuel pump, wiring blah blah.

In the end he called his tech team for a wiring/fuse diagram. They commented (which was nice to know) that they never really get asked questions about Subarus' as they never go wrong. Anyway, they found a diagram and told us to check fuse 11.

Sure enough, it had blown. It was a 15amp fuse.

He didn't have a spare 15, so we bunged in a 10.

Turned the key, fuel pump primes.

cool, the car starts.

Now, the label for fuse 11 says AIRBAG/IGN

Does anyone know what else this fuse feeds ?

My fuel pump had only been in the car for 2 weeks. Its a Lateral Walbro uprated super high flow pump.

I started the car this morning and it fired up for about 3 seconds and sure enough it cut out again. It does this everyday as I've just had a simtek fitted by Bob and the cold start map needs a bit of fine tuning which will happen next week.

The car then wouldn't start. I checked the fuse and it had blown again.

So at that point I only had a 25amp fuse left, so I bunged it in and the car started. First place to drive to was a car parts place so stock up on a shed load of fuses.

So, I'm wondering what is causing this. I think if the car stalls because of the fuel map on the simtek, it might be triggering the fuel pump to cut out and then it perhaps overloads the fuse ? I'm no electrical expert.

I've got enough fuses to keep me going now so I'll have to see.

Also, do you think it would be a good idea to put the fuel pump on it's own separate power feed ?

Any advice welcome.

dunx

iTrader: (3)

Higher capacity pump may be drawing a greater current at startup, hence the blown fuse, I would try 15 Amp, BUT you may need to go to a 20 Amp fuse to avoid it blowing regularly.

IMHO

DunxC

P.S. As a fan of your car , would you recommend a Simtek on the way past 400 bhp ?

marklemac

Thanks DunxC.

I have put a 20 in at the moment and all is fine. Might try and go back to the original 15amp at some point to see what happens.

Ecutek is fine for mid 400's.

But when you on your way to 500, then it just doesn't seem to be up the job, hence the reason for switching to the Simtek.

Bob is doing some more mapping for me this weekend to refine the low end map and also to hopefully run some more boost

alcazar

iTrader: (2)

Can you get hold of a spec sheet for the pump? It just might be drawing over the 15 A and your fuse melts on startup as this is when it draws the most current.

You could always insert a relay, using the present wire to trigger the relay, and feed the relay direct from battery via an inline fuse of whatever rating is necessary.

Alcazar