420 SEAC - not starting

[Ian350]

I can't see reference to this anywhere else so apologies if I'm repeating what's ben said before.

My SEAC sometimes refuses to fire on trying to start, hot or cold. This happens 1 time in 20. I can see there is no fuel pressure when this happens so have changed the fuel pump relay. Funnily enough the best fix seems to be taking the relay out and putting it back in again, but this doesn't always work. Before I book this in with my local autoelectrician can anyone tell me is this simpy a bad connection to the fuse board or is this a well known problem with wedges?

Any help much appreciated as this is really spoiling my enjoyment of this magnificent beast!

Thanks

Ian

[mrzigazaga]

Hi Mate.
You should count yourself lucky mines the other way round..Starts 1 in 20...
I think all wedges have some electrical issues considering that it was not TVRs forte..Its always worth checking the earths..Check for loose connections to coil, Leads, Battery...Pulling out and putting back the relays are part of the TVR maintenance program..
I would first ask the auto-electrician to check for any loose connections behind the relay and fuse boards..Im not sure what colour your fuel relay wires are though but someone else might be able to help on that one..
Im sure that the TVR wiring tech was italian as the wiring certainly looks like a plate of spaghetti..
Good luck..Ziga

[Number 7]

When you say you can see that there is no fuel pressure, do you mean that the pump is not priming when the ignition is switched on but before cranking? Had similar intermittent problem with mine some years ago. Turned out to be a strained & corroded connection in the back of the board to the injection relay. Maybe you moving the relay around is re-making the connection temporarily.

[grahamw48]

When my 390 point-blank refused to start (totally dead, not even a click from the starter motor)it turned out to be a bad earth strap from engine to battery.

An intermittent bad earth could be causing your fault too.

[Ian350]

Thanks for the replies so far.

I have a gauge on the fuel line under the bonnet. When the problem occurs the engine spins over freely but the gauge doesn't move at all.

Then after some tinkering/waiting and trying again the needle on the gauge flies up and all is well again.

[cuneus]

Ian which SEAC do you own ?

[Mr Tank]

cuneus said:

Ian which SEAC do you own ?

One which doesn't start!

[E Ponym]

Ian350 said:

Thanks for the replies so far.

I have a gauge on the fuel line under the bonnet. When the problem occurs the engine spins over freely but the gauge doesn't move at all.

Then after some tinkering/waiting and trying again the needle on the gauge flies up and all is well again.

You need to tinker systematically when this happens.

So only touch one thing at a time, checking between tries - and see what makes the difference.

If this doesn't happen when you are driving then there is only a small section of wiring that could be at fault.

At least you have the gauge to let you know when it works.

Assuming it is a flapper engine - otherwise other rules apply.

The fuel pump is powered through a circuit that is controlled by the flapper, open the flapper by hand with power on to see if pressure comes up.

Another circuit powers the fuel pump when the engine is cranking so there should be a circuit from the solenoid/lock (2nd position) to the fuel pump.

As an earlier poster has suggested you need to check earths as well.

Russ

[Ian350]

cuneus said:

Ian which SEAC do you own ?

Its F171DGK - formerly Tim Lamont's and Russ Hargrave's

[Ian350]

E Ponym said:

You need to tinker systematically when this happens.

So only touch one thing at a time, checking between tries - and see what makes the difference.

If this doesn't happen when you are driving then there is only a small section of wiring that could be at fault.

At least you have the gauge to let you know when it works.

Assuming it is a flapper engine - otherwise other rules apply.

The fuel pump is powered through a circuit that is controlled by the flapper, open the flapper by hand with power on to see if pressure comes up.

Another circuit powers the fuel pump when the engine is cranking so there should be a circuit from the solenoid/lock (2nd position) to the fuel pump.

As an earlier poster has suggested you need to check earths as well.

Russ

OK thanks Russ, I'll work through that next time I have the opportunity

[blaineuk]

It would still start and run for a few seconds even with out the pump runing, I think.

[Ian350]

Update - the car was delivered to an autoelectrician who couldn't find anything wrong. Needless to say the car ran perfectly while he had it. Nevertheless the fuse board was taken out and connections cleaned up and remade.

Now the good news! Following what seemed like a misfire for a few miles the beast conked out on a fast A road. 15 mins of tinkering whilst waiting for the AA (again) got it fired up again and I drove it back home and straight into the garage where I left it for a day. Now there is no fuel pressure on the gauge and no amount of tinkering or checking is having an effect. Hopefully the fault is now permanent and therefore traceable!

Given that it scraped through the MOT emissions despite being "fully adjusted" and has a 5 litre V8 developments engine I wondered who to trailer it to as some tuning as well as electrics may be required. Any suggestions please? (I live in Cheshire so Manchester or Lancashire may be the best option)

Thanks

[cuneus]

http://www.xworksservice.co.uk/

[mrzigazaga]

Hi Mate..Just a wild guess..Have you a fuel accumulator..If so does it have an air pipe coming off the back of it..If it has clamp it about 3" up from the accumulator and then operate the fuel pump to see if petrol leaks out from where the pipe connects to it..If it does thats where your fuel pressure is going..Ziga

[Number 7]

Could be something as simple as the fuel pump failing / failed. Have you tried wiring it direct?

[grahamw48]

Ian350 said:

Update - the car was delivered to an autoelectrician who couldn't find anything wrong. Needless to say the car ran perfectly while he had it. Nevertheless the fuse board was taken out and connections cleaned up and remade.

Now the good news! Following what seemed like a misfire for a few miles the beast conked out on a fast A road. 15 mins of tinkering whilst waiting for the AA (again) got it fired up again and I drove it back home and straight into the garage where I left it for a day. Now there is no fuel pressure on the gauge and no amount of tinkering or checking is having an effect. Hopefully the fault is now permanent and therefore traceable!

Given that it scraped through the MOT emissions despite being "fully adjusted" and has a 5 litre V8 developments engine I wondered who to trailer it to as some tuning as well as electrics may be required. Any suggestions please? (I live in Cheshire so Manchester or Lancashire may be the best option)

Thanks

Didn't you let the AA man have a good look ?

They're usually pretty good at solving such mysteries.

Call them to your house first before taking it anywhere...or tow it up the road if you don't have homestart cover.

[adam quantrill]

Sounds like the fuel pump has finally failed (after being intermittent) and stopped delivering pressure.

Before you replace it get a pre-filter installed - a lot of cars are suffering from rust inside the tanks which knackers the pump.