Fuel pressure problem?

[DuncanM]

Hello everyone,

The joys and woes of the TVR Cerbera!

Having very recently put the car back on the road I have been expecting issues and I was right!

It was running well at first but now has a problem that feels like it is running out of fuel at low rpms <2000.

At first I thought it was a misfire, but I have changed Coils/Leads/Plugs, and the symptoms are still there.

The plugs that came out all looked healthy.

I am thinking now that it is Fuel pump/Fuel filter related, the car has sat for 5 years so I guess it can be expected?

So, how easy is the fuel pump to change? We've already done a filter but will check/change it too.

I have found this Fuel pump: http://www.fuelpumpsonline.co.uk/bosch-fuel-pump-0...

The spec is direct replacement for the Bosch 0580254957/909

Any tips/advice/help will be gratefully received.

Regards

Duncan

[Gazzab]

Could it be tpots?

[Gazzab]

Did you drain and change the fuel as petrol goes off.

[DuncanM]

Hello, No problems with the TP's as far as I can see with the diags (no faults logged for ANYTHING).

Regards the fuel, I have used well over 1 full tank since it was off the road.

I am still concerned about the condition of the tank though tbh as it was sitting a while.

I'll let you know how I get on on here, I hope it is the fuel pump/filter as that makes sense to me.

Regards

Duncan

[Brummmie]

The wiring could be going rotten, run a direct feed from the battery.
Just do it rough outside the car from battery to pump, with a length of wire, the pump may whizz faster then.
I upgraded my pump, and the standard "speaker" wire couldnt handle it, plus it was past its best.
HTH.

[DuncanM]

Thanks Paul, that could be it you know as I had problems before where the pump wouldn't prime due to the wiring being poor. The electrician did re-wire from the relay and that sorted out the starting problem.

Duncan

[DuncanM]

Still have a problem with my Cerbera unfortunately.

I have recently had the fuel pump changed and a new charging fuse when we found it was burnt out.

The car is over fueling once hot, it is awful under 2000rpm. Really bad.

I have recently changed the plugs and leads.

My next step will be to remove the injectors and have them cleaned.

Despite recently doing the coil packs I am considering buying some to swap out.

If ANYONE has any suggestions as to what to check regarding this issue then please post.

The adaptives are ok at idle but then are -20% when revving to 1500 > 2000 rpm.



All of these problems have arose since putting a new exhaust with linked de-cat pipe on. I am thinking of putting the cats back on just to make sure it's not the cat pipe although I can't imagine it being so?

Regards

Duncan

[GT4 Baz]

Did the Lambda sensors get knocked/moved/disturbed during the exhaust changes?

[JensenA]

Get the diags hooked up and reset all the adaptives, let it 'learn' how to fuel for the new exhaust.

[DuncanM]

Hello,

I have reset the Adaptives more than once trying to resolve this .

Two questions if anyone would mind helping:

1) Does the cerbera have a engine temp sensor (not water temp) and if so where is it please?

2) Could my problem be to do with the fuel pressure regulator?

Regards

Duncan

[tur8o]

mine was mis-firing and running terrible last year. sent it to the garage and after much head scratching and trying various ignition parts etc. it was the regulator. garage said i was lucky it didnt go up in flames, fuel pressure was through the roof, nearly 6 bar i think!

[DuncanM]

Thanks for the reply Rob,

This is very interesting to me as I have not seen this issue since being a member here (7+ years) and I also can't even find the part on TVR parts shops such as Clevor Trevor? very strange but it does seem to be a possibility because my car is over fueling horrifically .

Thanks again, I'll update this thread once I get to the bottom of it .

Duncan

[Alan Kee]

It can't run rich as such because the lambda feedback ensures that the engine runs at lambda1 anyway, so despite the 20% trimming on the lambdas it will still be running at lambda1. It does sound like you have a running issue if the car feels poor to drive, but are you thinking its running rich also because of the smelly nature of decatted cars? If the trimming stabilises at -20% and isn't running to the limit of 35% then it isn't running rich, its running at lambda1 IYSWIM.

[DuncanM]

Thanks Alan,

Unfortunately my laptop battery is dead so I can only check diags whilst the car isn't running.

I understand what you're saying, the adaptives are coming up as bad when the car is revved so I can only assume that it is out of the range that the ECU can adapt to?

I'm not ruling out Coil packs despite recently putting new ones on.

The other day I removed up to 4 injector connectors and it acutally smoothed out the idle!

Very hard to diagnose when the car runs a nice 1000rpm idle with only 4 injectors connected.

Regards

Duncan

[GT4 Baz]

I won't be too far from MK tomorrow if you want to borrow my lap top (I don't have the software myself, but I could download it in advance/transfer it from yours).

Mine is a 4.2 if that helps you could swap some of the parts over to help diagnose?

Just a thought.

[DuncanM]

That's very generous Barry Unfortunately I have a chance to look at the car until Monday now due to half term (doing stuff with family instead of car!).

I am ordering a usb > serial port adapter so that I can use my new laptop rather than my old knackered one.

Would be nice to meet up some time though, it's nice to know there are some other Cerberas about .

Regards

Duncan