Car won't start

[H286]

Crap the car won't start now: I can start it once a day and it runs for <10 seconds before spluttering to a stop. Then won't start again.

Fuel gauge shows half a tank. I will put 5L in as the symptoms are of empty fuel tank.

I was messing around with the fuses wonder if I have dislodged something.

The car is fitted with an imobiliser.

Any ideas welcome.

[H286]

It starts first time and runs fine for about a couple of second before spluttering to a stop over the next few seconds.

[easytrans]

Fuel pump relay?

If I remember correctly when it cranks over it will use some part of the relay and supply fuel then as soon as the key is let go of then it will fail !! try the bypass method .....

Take a live wire direct to the fuel pump to confirm ( I used a wire from the offside rear tail light and put the side lights on to power the pump just to test)

Worth a try.
Laurie.

[easytrans]

Fuel pump relay?

If I remember correctly when it cranks over it will use some part of the relay and supply fuel then as soon as the key is let go of then it will fail !! try the bypass method .....

Take a live wire direct to the fuel pump to confirm ( I used a wire from the offside rear tail light and put the side lights on to power the pump just to test)

Worth a try.
Laurie.

Just quoting Darren on an earlier post from 2016 on a similar issue ....

"
the fuel relay is actually 2 relays inside the casing. as laurie said, one winding is solely for the fuel pump, the other winding does the airflowmeter, injectors, portion of the ecu which triggers the coil driver, various engine sensors or other valves depending on age of vehicle. ecu wont pull the second relay winding until it seems a crank signal."

L.

[AndyGee]

Aye, agree with the above, back to basics.
Put 12V positive and neg directly onto the fuel pump (it is easy to get to) to power the pump up and try to start the engine.
If it starts and continues to run ok, you know the problem is with the fuel pump electrical supply, and nothing to with the ignition, fuel supply, crank sensor, e.c.t.

Good luck...

[H286]

ok will test the fuel pump next although I might have found the cause of the problem.

I wasn't seeing +12v on the fuse terminals for the fuel pump fuse. (The fuse box under the drivers side dashboard)

I did remove the fuel pump fuse (fuse 16) (in error then put it back) when I was working on the radiator fan issue. I am going to pop out the fuse box and confirm the connections at the back are correct in case i caused a connection at the back to become disconnected.

[H286]

The car does have an imobiliser but not sure how that is wired in. Anyway the starter motor is turning which wouldn't happen if the imobiliser was active.

[H286]

I forgot to say, I bridged the relay and there is 12V at the relay. (The 12V from the relay goes to the fuse)

[H286]

Just quoting Darren on an earlier post from 2016 on a similar issue ....

"
the fuel relay is actually 2 relays inside the casing. as laurie said, one winding is solely for the fuel pump, the other winding does the airflowmeter, injectors, portion of the ecu which triggers the coil driver, various engine sensors or other valves depending on age of vehicle. ecu wont pull the second relay winding until it seems a crank signal."

L.

Thanks for the point about the 2in1 relay - That made me realise I was looking at the wrong circuit diagram, so may have bridged the wrong points. I now have the 1990 circuit diagram which shows the two 2in1 relay so can work from that.

Hopefully won't need to touch the fusebox as I am reluctant to pop out the fuse box as it looks like a pain to get out. I can see it has been out before as there are screwdriver marks where it has been levereded.

Will update after I have done some more checking.

[mick g]

The car does have an imobiliser but not sure how that is wired in. Anyway the starter motor is turning which wouldn't happen if the imobiliser was active.

Immobilisers sometimes just cut the fuel pump supply which would mean it runs briefly then stops..See if you have 12v to the pump whilst its running

[H286]

Here are todays updates: I bridged the relay in the correct points and there is +12V at the fuse With the bridge in place there is a swirling noise from about the above the injectors and the pump can be heard running. However the car will not start with the bridge wire (as shown in the below wire).

When I put the relay back the car turns over and doesn't start at all anymore.

So I'm guessing I should power the pump independently? But not sure why the bridge wire doesn't do the job?

[H286]

to correct what I say: The car will turn over but not start with the bridge wire.

[H286]

I put 5L of petrol in the tank the other day and the fuel level increased to just over the half-way point on the dashboard.

[easytrans]

I'd not like to comment on what the bridge wire would or wouldn't do as I assume that you isolated the relay totally when doing that?
I would try the simple test of running a single strand of wire from the rear sidelight + wire down to the fuel pump under the rear (its an easy thing to do just add the wire in with the existing push on connector at the pump) and then switch on the sidelights dnd crank it over. if the car starts and runs just replace the relay as that will be the culprit (I've had at least three give up over the years)

Easy peasy

L.

[H286]

Ok - will the sidelight wiring be up to the fuel pump motor current required?

That is the next easiest thing to do. Like you say will tell us if the relay is playing silly buggers.



I'm hoping that when I bridged 30 to 87 I didn't do any damage.

If I still have no luck I will need to check the sparking is still happening.

Not sure if the car has cam position sensor.