guinnessman2001

Hopefully some of the experts on the forum can give me some pointers.

Sitting at lights tonight on the way home from work and the car just died. All dashboard lights were on as normal, engine spinning round on the key but just wouldn't fire.
Two minutes later it fired up as normal and has been fine ever since.

A few days ago as I was driving at a steady speed the engine died momentarily. However after about ten seconds it fired from the key before I had even rolled to a halt.

The car is a MY99 Uk turbo with 115k on the clock. This is the first problem I've had in almost 3 years of ownership.

My first thoughts are the fuel pump may be on the way out. I've got all the previous owners receipts and there is nothing to indicate the pump has ever been changed.

All help will be gratefully received.

Thanks

P4UL

iTrader: (1)

Sounds more like an ignition issue, possibly an intermittant earth fault.

prodriverules

iTrader: (52)

as above mate id say ignition,could be earth or coil on its way out fella,or the crank sensor,it would need to be playing up though the track the fault

guinnessman2001

Thanks for those suggestions, however if it was a crank position sensor would it not have thrown up a CEL error?
The CEL always comes on and goes off as normal after starting the car.

One thing I maybe should have mentioned earlier is I don't think the fuel pump is making as loud a noise as it used to when switching on to pressurise the line. You get used to the regular noises from your car and maybe it's just my imagination but the pressurising noise doesn't seem as promient.

However if any other experts think it is an electrical problem then I'll start with checking any earths before replacing the coil pack.

Thanks again.

Splitpin

As you have already worked out, the symptoms you're reporting don't fit too well with the suggestions you've already received. I certainly wouldn't shell out on a new coilpack, at this juncture, at least.

It is unlikely to be a "coil on its way out", as, while not impossible, the design of the ignition system means a fault of this sort is more likely to cause the engine to drop onto two cylinders rather than to cut completely. It is also unlikely to be the crank or cam position sensor because, as you correctly surmise, either of these will cause the check engine light to illuminate if they bug out while the engine is running. Similarly a fault with the airflow meter would cause a CEL if it was serious enough to kill the engine.

It is also unlikely to be "earths" given the description of the problem (in particular that it is intermiittent). An issue with the main engine ground, for example, would typically cause a wider set of symptoms that don't magically clear up completely, and in most cases a ground fault would cause problems in enough areas to trigger the CEL. Although this does not mean that it isn't an electrical issue of some sort - there are a number of circuits that the ECU is unable to monitor, and therefore unable to raise an error code when there's a problem. The fuel pump is one of them.

If you haven't seen the check engine light associated with this problem, your surmise with the pump is probably the first thing worth following up and ruling out. Unfortunately though there are a number of potential causal factors. Could be that the pump itself is on its way, or it could be a fault in the power supply to it - the connector under the back seat, the fuel pump relay, or, if you have a UK specification car with the Sigma M30 alarm (or indeed any other cat 1 system), it's also possible that a worn relay in the alarm control unit could cause something like this.

Check all the connections in the pump loom for good fit or signs of arcing - in particular that one under the back seat. One other possible diagnostic step would be to swap the fuel pump relay with the front foglight one - they should be the same type. If the problem doesn't recur, you can be reasonably confident you isolated the cause. If (as is likely) this doesn't solve the problem, then move onto the next issue.

If in doubt you could always electively replace the OE pump with a new Walbro unit. Bottom line is that the original item is now 11 years old so it's had a good working life.

Have you seen the check engine light at all when this problem has presented? Your posts read as though you haven't but clearly it's worth connecting the black plugs and checking for stored fault codes, just in case there's something interesting hiding away there.

guinnessman2001

Many thanks Splitpin for the comprehensive diagnosis. Your Subaru knowledge is amazing.

The CEL has never illuminated, apart from ignition switch on, and goes off again as expected after a few seconds. However I'll check for any stored codes.

Apart from this problem the car is running faultlessly, no missfire or surging, and pulls smoothly across the rev range.

I am electronics engineer so should be able to eliminate any obvious earth faults but as you suggest I'm being drawn to this being a fuel pump issue.

I will remove the floor panel and check all the connections at the fuel pump, then move on to the relays.

Just one point, the car is totally standard so do I need a Walbro pump or will a stock Subaru one suffice.

Yet again, many thanks for all who have taken the time to reply.

midnight

iTrader: (10)

I had identical symptoms on my MY 1999 uk turbo,car would cut out then start after3 - 5 mins,it was annoying as it would happen at any time.Eventually turned out to be the fuel pump.If the car should cut out again ,when you turn the ignition key listen to see if you can hear the pump priming,if not then the pump could be about to fail.As said above your car is 11 years old now and the fuel pump has had to pump fuel for some 115,000 miles,so it can be prone to failure.
Regarding buying a walbro pump(£58) ,you might as well buy one of these imho. as it will be cheaper than buying a std 'coke ' can(early classics to 99) replacement from subaru uk. You will also have piece of mind that your pump is delivering enough fuel to your engine.

guinnessman2001

Looks like it will be the pump after all. After checking the wiring and relays I will order a Walbro one.

Final question, can someone tell me the best place to buy one from. I'm based in central Scotland


Thanks again to all who replied.

JohnD

iTrader: (5)

Do check the connector under the rear seat I believe there have been issues with this on classics, from prevoius posts on here.

JohnD

guinnessman2001

I had a new Walbro pump fitted yesterday and thought that would sort the problem.
Unfortunately, arriving home tonight after my 50 mile daily commute, the car just died again. I was accelerating hard at the time and the car just coasted to a halt. The engine would spin round freely but would just not fire.
The recovery guy checked out all four leads from the coil pack and they were all sparking fine so he surmised the problem was fuel related.
The pump could be heard pressurising the line when the ignition was turned on but it still wouldn't fire.
He then suggested no fuel, but although the level was low the petrol light had not illuminated. The recovery guy thought the replacement of the pump may have misaligned the tank float leading to a wrong gauge reading.
So he pulled the car onto the flatbed and drove to the local garage. Half filled the tank and the car fired up first time. The car ticked over perfectly for fully five minutes but on driving the last 500 metres to my house it just died again. Engine spinning but would not fire.
After two minutes the car fired up again as normal. I stopped and started it about a dozen times and it fired up every time.

I am still thinking the problem is fuel related plus there are no error codes indicated.

The wiring connections to the pump under the back seat are fine so as Splitpin suggested maybe I should check out the relays next.

So could some expert please tell me where the fuel pump and alarm relays are to be found?

Apologies for the long thread but I wanted to get over as many facts as possible.

The car is a UK MY99 Impreza Turbo and I'm taking really badly with the only faults I've had in nearly three years of ownership.

As before, all suggestions will be gratefully received.

just123

iTrader: (1)

Faulty fuel pump relay in drivers footwell

Big 'D'

Was there not a common issue with the Sigma imob' and the fuel pump power supply that caused intermittent cutout and eventually total failure to start?


Cheers Iain

guinnessman2001

I had the car out today for a run, only ten miles, but it ran perfectly.

I wasn't aware of any issue with the Sigma alarm but thanks for the pointer.

Am I right then in assuming that there is only one relay for the fuel pump. The control voltage being through the ignition plus the Sigma alarm. Therefore if there was an intermittent problem with the alarm, then the drive to the fuel pump relay could be lost.

The next question then is can the fuel pump cut out from the alarm be disabled? So that the relay is only energised from the ignition signal.

I'm out of the country for seven days from Monday, but any further suggestion or help given between now and then will be gratefully received.

C17RPA

fuel filter? blocking up?

guinnessman2001

There was a new bag filter fitted onto the replacement Walbro pump and the can filter under the bonnet is only six months old.

However I believe there is a fuel pressure regulator somewhere in line, so could that fail and stop the fuel flow?

Big 'D'

The fuel pressure reg is mounted to the fuel rail and is a very simple little pressure valve, it is not likely to fail but it would be worth checking that the vaccum pipe fromthe manifold to the FPR is secure and in one piece.

Cheers Iain

guinnessman2001

I'll check out that pipe, although if it was damaged in any way would the car not surge or splutter before dying?

When my car breaks down it stops instantly, as if something has just been switched off.

I'm still being drawn to this being an electrical problem, however any other suggestions will be very gratefully accepted.

Thanks to all who have already replied.

Setright

You need to bypass that alarm/imob...

bobby chang

This is what happened to my 99 turbo last year, and that is what I did.

John 37

if you do that, wire the ign supply through a hidden switch and don't tell ANYONE about it. Ignorance is the best security.
If you can't hide a switch, I've done the same with a latching relay. If you trigger it from an instataneous or intermitent supply like the RSH or reverse lights, it will be naturally hidden and cannot be left switched on.
You will need to be able to link it out if ever your car goes into a garage though.

John

Eternal Rage

iTrader: (7)

As mentioned worth checking the Fuel Pump Relay, there are a few relays behind where your right knee would be in the driving position, tucked right up and away in the depths of the wiring.

Its round with a green top if memory serves me correctly.

bobby chang

Yeah, it's a very good idea, never thought of that. Since I use the car to & from work only, and hardly take it to anywhere else, so not bother at a moment, the car not even have wheel locks on it for easy access as I always work on the car.