2004 Meriva A, now it won't start at all.

why not just wire in a fuel pump feed and drive it?

Whilst I'd be happy to do that as a test prove the point, I'm not sure it would be a good idea in the event of a crash etc would it?

Cheers, T i m

I expect it has an inertia switch, just wire it through that.

Oh ok thanks.

Can you answer me this though please. When it sometimes starts it just runs for 1 second and then stops (often to not start again for a while). If I then power up the fuel pump with the OpCom it doesn't then start afterwards, So, is there some high pressure fuel stored somewhere that the fuel pump isn't able to replenish (inside the injector / injector pump etc)?

The pump I hear when I power up the 'fuel pump' seems to be coming from the rear so I wouldn't think that would be pumping high (injector) pressure fuel from back there would it?

(Sorry, whilst I understand the principals of fuel injection I'm not familiar with it practically).

Cheers, T i m

The pump is at the back and can deliver about 60 psi to the front, there is a pressure relief valve which keep the normal run pressure at about

40 and keeps the pressure there for a while (should be overnight at least) which is why it can run the engine for a moment or two if you try to start it without the fuel pump running. A simple pressure test can confirm whether fuel pressure is normal. Running the pump for just a few seconds should be enough to bring pressure back to normal (again a simple pressure test)

So, there is no other 'reservoir (even if it's just inside a hose or high pressure pump body etc) of fuel held at a higher pressure somewhere would allow the injectors to inject for a second or so?

I'm not feeling the link between the low pressure feed and what allows the car to fire up instantly and then die (like a very small float bowl on a carb rather than what fuel may be in a fuel line etc).

I ask because I'm not sure that running the pump manually has ever then allowed the car to restart, even for that second?

Hmm, well, whilst that may be happening it doesn't seem to help, but if / when it does start it runs fine even at speed (normally a test of fuel flow if I remember my principals correctly)?

I'm just thinking out loud of course and trying to match it to what I have seen many times (it starting quickly and easily with just a dab of the key an then trying a second later).

Cheers, T i m

p.s. In the old days you would rig up a bucket full of petrol and some piping and hang it from the bonnet catch ... ;-)

No there is no pressure reserve tank (older cars had one), although the fuel pump,the filter and the piping act as such. if one day it will run normally, turn it off, pull the fuel pump fuse and when you try to restart you will find it runs for just a second or so. Like I suggest, get a fuel pressure tester and see what you actually have in the no start condition. As to the bottle of petrol and a hose, I made up the modern equivalent of a spare pump and a can !! It does of course run unrestricted presure so it is a bit rich, but it can help diagnosis, just as a ressure tester can. On some cars there is a schrader valve, so you can use a tyre pressure gauge (with care)

Ah, ok (thanks), and so do you think that would be enough high_pressure_capacity to allow it to run for about a second?

Understood (and should answer my question above etc).

Will do. OOI, Is it possible the pump pressure could be sufficiently low to be on the threshold of whatever would need to be opened next (injector pump presumably) yet still allow the car to run 'perfectly' once it does start?

Showoff (with yer fancy pumps). ;-)

Looking here:

Many seem to add 'except for cis-jetronic, bosch and gm throttle body systems'. Would the Meriva be a 'GM throttle body system'? ;-(

So, I'm hoping for a Schrader valve somewhere or would it be something you would have to 'plumb in', albeit temporary?

Thanks again, cheers, T i m

the fuel pump is the injection pump, the injectors on most cars are in atmosphere (effectively), so the pressure needed is not great. if the pressure available was too low to allow starting but high enough to run then it would keep going after a puff of easy start.

the pressure regulator valve in the system is what maintains the pressure at the engine end (otherwise the fuel would just continually circle back to the tank at a very low pressure) If that fails then it won't go, again a pressure test will show it up.

I cannot remember ever needing to test fuel pressure on a petrol vauxhall so I don't know where the connector is, some cars you need to add in a t piece to measure.

Oh. I was thinking they were at some silly pressure but then that could be diesels?

Good point.

Understood and thanks for the explanation.

Which suggests something as well possibly?

Understood.

Thanks again Mr C ;-)

Cheers, T i m

replying to Mrcheerful, Robert stirling wrote: Did you ever find out the problem? As my Meriva is behaving the same way but I think it's to do with the instrument cluster

Hi!

Did you find the couse of the problem? Unfortunately I have the same issue now with my meriva. First the odometer failure and now the engine wont start.

it's common for the fuel pump to go , of you give the fuel tank a wake with your hand it jolts the pump to work briefly , then you know the pump is worn. and requires replacement , if it's not that then check the fuel pump relay as they stop working regularly. ?