Engine cut out on track. Fuel pump relay!?
13 August 2017, 12:26 PM
#1
Engine cut out on track. Fuel pump relay!?
Just wondering if anyone has any ideas with this one. On track at LLandow yesterday and car running well all morning. First session out in the afternoon and after braking hard for a tight corner and trying to get back on the power, discovered the engine had just died and would not restart. Coasted to a stop and had to be towed back to the pit lane. No warning beforehand, no engine lights. It just died. A bit of help diagnosing from a few others - the fuel pump isn't priming when switching the ignition on.
So it turns out that the fuel pump relay has given up the ghost, the (incredibly helpful) garage I had it taken to called first thing today and said the car is running fine after bypassing the relay so they are going to replace it and also get me a spare for if it happens again.
Massive relief that its not a major problem. However I am left wondering what could have caused this. Could there be a problem with with the fuel pump perhaps? Car had been driven quite hard during the morning and it happened after braking from about 100 down to 30 for a very tight corner. It may or may not be related but it also had used an astonishing amount of fuel compared to usual - I got through half a tank in just over 50 miles.
The car had near a full tank at the time it happened (as I had just refilled it with Tesco99Ron). Its a bug impreza Sti on standard turbo with the usual standard mods: remapped to about 330bhp, walbro 255 fuel pump, sport cat.
As a side note - I Really lucked out as some great guys from 'The Garage 29' in Cardiff who were also on track really saved our Bacon by coming all the way back to the circuit to trailer me off to their garage and drop us at the train station after getting their cars home. Anyone in the Cardiff area after a decent mechanic I would massively recommend them. Subaru specialist, really friendly helpful and knowledgable
So it turns out that the fuel pump relay has given up the ghost, the (incredibly helpful) garage I had it taken to called first thing today and said the car is running fine after bypassing the relay so they are going to replace it and also get me a spare for if it happens again.
Massive relief that its not a major problem. However I am left wondering what could have caused this. Could there be a problem with with the fuel pump perhaps? Car had been driven quite hard during the morning and it happened after braking from about 100 down to 30 for a very tight corner. It may or may not be related but it also had used an astonishing amount of fuel compared to usual - I got through half a tank in just over 50 miles.
The car had near a full tank at the time it happened (as I had just refilled it with Tesco99Ron). Its a bug impreza Sti on standard turbo with the usual standard mods: remapped to about 330bhp, walbro 255 fuel pump, sport cat.
As a side note - I Really lucked out as some great guys from 'The Garage 29' in Cardiff who were also on track really saved our Bacon by coming all the way back to the circuit to trailer me off to their garage and drop us at the train station after getting their cars home. Anyone in the Cardiff area after a decent mechanic I would massively recommend them. Subaru specialist, really friendly helpful and knowledgable
13 August 2017, 02:27 PM
#2
That a great result all round for what could have, and probably felt like a nightmare.
Hat off to the garage people!
Unsure on your issue with the electrics, but given your car must be pushing 15 year old, and you describe you haven't gone easy on it, possible chance of a broken wire somewhere?
Robert
Hat off to the garage people!
Unsure on your issue with the electrics, but given your car must be pushing 15 year old, and you describe you haven't gone easy on it, possible chance of a broken wire somewhere?
Robert
13 August 2017, 03:12 PM
#4
Absolutely! I feared the worst initially, but after realising the fuel pump wasn't priming I felt a bit more positive.
The guys I mentioned were fantastic, so good of them. It would have been much less hassle to have said 'good luck mate' and been on their way.
Car has been maintained well and has just had a fair bit of work done to it refreshing a number of bits including suspension, engine hoses etc. Its had a pretty easy life in general and hasn't been used a lot over the last few years as most of my spare cash has gone into house renovations.
Like you say approaching 15 years old - so for sure, minor bits wearing out to be expected especially as I start giving it a bit of track use. Trying to avoid the issue repeating itself. Could be a wire or a fuse...I guess if it happens again after the relay is replaced it might be a good place to start looking.
The guys I mentioned were fantastic, so good of them. It would have been much less hassle to have said 'good luck mate' and been on their way.
Car has been maintained well and has just had a fair bit of work done to it refreshing a number of bits including suspension, engine hoses etc. Its had a pretty easy life in general and hasn't been used a lot over the last few years as most of my spare cash has gone into house renovations.
Like you say approaching 15 years old - so for sure, minor bits wearing out to be expected especially as I start giving it a bit of track use. Trying to avoid the issue repeating itself. Could be a wire or a fuse...I guess if it happens again after the relay is replaced it might be a good place to start looking.
13 August 2017, 03:23 PM
#5
Ok so its not out of the question that its simply the relay itself has worn out then. Agreed mpg dips right down on track, in past I have seen low double figures. But yesterday it was about 6mpg! I wasn't holding back, but I'm no Lewis Hamilton 
After getting the car off track one of the chaps from the garage disconnected the fuel hose in the engine and fuel sprayed out everywhere. He said that was not normal and fuel pressure was far too high. Probably was just a result of the relay failing. I always try and keep over about half a tank full when on track to err on side of caution.
After getting the car off track one of the chaps from the garage disconnected the fuel hose in the engine and fuel sprayed out everywhere. He said that was not normal and fuel pressure was far too high. Probably was just a result of the relay failing. I always try and keep over about half a tank full when on track to err on side of caution.