Been talking to chrisgrain about his XE non-running issues and have to say really struggling for an answer.

Basically its either got no compression or the fuelling is WAY out.

The injection system is still firing, and still firing sequentially at that, so both crank and cam sensors are working.

The timing marks are all still lined up and it has good, well timed sparks on all cylinders.

I asked about possibility of blocked exhaust but it seems unlikely and apparently burbles from it on cranking so seems unlikely.

I pondered about broken inlet cam (exhaust is ok as dizzy still spins) but it seems very unlikely and mixture is getting into the cylinders on all pots so can't really be.

Throttle position switch is operating at least something like correctly (i.e. its switching over on initial throttle opening)

Only thing I could think of was could the fuel return line be blocked or the regulator have failed shut?? Both are unlikely, but has anybody had such a thing happen, and what was the effect??

I would imagine huge overfuel, but I've never had it happen!

When you say the injection is fireing do you mean fuel is seen coming from the injector/s or that there is an impulse at the injector wires.
When I had my Cat on Emeralds RR a few years ago I had a couple of sets of top feed Focus injectors and a set of VX injectors to try out. All of the injectors were the same impedance and the flow rates were checked and they were all very similar on the flow bench where the VX ones obviously seemed to be working.
However, when in the car , although the Focus ones worked perfectly there was no flow from the VX ones and I never did find out why.

Fuel is spraying from each in turn, in the firing order, while they are installed in the inlet manifold.

If its over fuelling badly enough to not start from cold then the plugs would be soaked, how about some easy start or carb cleaner in the air intake to see if it fires.Injector timing doesnt really matter and if theres a spark timed corrrectly it should at least fire.
Paul.

This ones been dragging for a while now and for me it is a very interesting one.
Seems like most bases have been covered sparks ok fuel ok fuel mix in cyls ok spark timing ok cam timing ok
Compression test????? but even if not a lot of compression surely a backfire or two would be in order??
An old trick i have used before is to pour a couple of kettles of boiling water over the inlet manifold to try and heat/aid vapourisation of the petrol air mix. It's helped me out a few times now especially on old manual choke cars where it is easier to flood them.
I hope you get this resolved guys I'm keeping an eye on this thread so good luck it's a very very strange one.

Disconnect the fuel pump relay , remove plugs and dry out cylinders, refit plugs then give it a squirt of easistart or brake cleaner (works just as well) If the engine fires and runs for a few seconds then fuel system is at fault if it doesn't then sparks/timing/compression etc are at fault. Best way to check for fuel return/pressure regulator fault is a fuel pressure test using injection pressure gauge.Bore wash will cause a drop in compression on a worn engine , it could affect a newer unit??

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Originally posted by NS Dev
Been talking to chrisgrain about his XE non-running issues and have to say really struggling for an answer.

Basically its either got no compression or the fuelling is WAY out.

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Right.... I am getting completely pissed off with this! I think the only thing that is stopping me deep sixing the whole unit is the help I'm getting on here...

Latest installment - after chatting to NSDev went and checked a few more things - both cams are turning (no broken cams) and the timing is definitely right - cylinder 1 TDC makes the 2 cam marks line up on the cam cover, and the cam lobes of No. 1 cylinder point away from each other....

The return fuel line isn't blocked (squeezed it whilst the pump was running and heard the turbulent flow, and also the pump tone changed as the pressure went up)

Took all the plugs out, and they are all wet with petrol - currently all still out, letting the whole thing dry.

I don't have a compression tester, so will get one, and also will try the 'disconnect fuel pump and easistart' once I've got some new plugs - just in case....

Any other suggestions gratefully received - getting very fed up

Thanks for the help though guys...

Chris

In the 18 years i was a techy for vauxhall i probably changed 2 or 3 regs that had failed, symptoms are massive richness,flooding and fuel leaks as the pump runs to its lock pressure of 8 bar or so.
Cats used to fail and block the exhaust but they generally fire then cut out or are reluctant to rev.
seen a few sheared crank gear/keys so the timing slips in relation to the crank, and seem to remeber one xe that pumped its lifters up due to a faulty oil pump or relief valve so had no compression.
Also the earth point on the fuel rail near the reg used to come loose and give fueling problems

Rich

Hi BigRich,

The earth point near the regulator, I've just earthed that to the manifold, should it be somewhere specific - can't imagine it should, but clutching at straws!

Chris

Have you tried a new set of spark plugs and HT leads (£147 from a dealer! bout £30 elsewhere) yet?

Its maybe woth checking all the vaccume and air inlet hoses for any leaks that could be making the mixture so far out.

My XE would never idle properly when there was a slight tear in the pear shaped gasket between the air box and the throttle body.

Does the engine sound to be turning over fast enough? is it worth putting the jump leads on to rule that out, also one from the battery -ve to the Ex manifold might help if its turing over slow.

Good thinking - new plugs and HT leads less than 100 miles ago! Cranking nice and fast from a freshly charged battery....

Will change the plugs again though, just to be sure..

Chris

I don't suppose you've still got the old ones then?... or did you change them because you suspected a fault then?

A quick check to do on yours might be tweaking the nipple bit on the top, I've had a few rescently that with the nipple tight you could twist it about 5-10 deg either way, and it was actually the centre core that was snapped! it would spark ok on the mainfold but wouldn't handle load in the engine. They'd probably only done about 100 miles.

Its more so for the Turbo engine but there's a few pointers on here t odo with the ignition LET Ignition

Theres's an interesting bit on 2 different heights of rotor arm, it could be something really silly like that.

Good Luck!

[Edited on 21/2/08 by MkIndy7]

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Originally posted by chrsgrain
Hi BigRich,

The earth point near the regulator, I've just earthed that to the manifold, should it be somewhere specific - can't imagine it should, but clutching at straws!

Chris

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Was running fine, until were slowing down and it just cut out... had done 100 miles since bottom end rebuild (hence the new plugs and HT leads).

I think you're right - compression test next - am away for a week from tomorrow morning - I'll do that soon as I get back... need a break from it anyway!

Chris

quote:

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Originally posted by chrsgrain
Hi BigRich,

The earth point near the regulator, I've just earthed that to the manifold, should it be somewhere specific - can't imagine it should, but clutching at straws!

Chris

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100 miles since bottom end rebuild? as someone pointed out it could be the hydraulic tappets pumping up (or pumped up) due to a sticking oil pressure relief valve? Do a compression test and if no or low check relief valve. Can't say I have had any problems with the Vauxhall lump but did once have the same problem with a Zetec. Are you using the correct oil ?Did you strip /replace oil pump ?

ahhh good one!!!

Thought of low oil press but not high!!!

now that is worth a check!!

If the followers are jacked up then I'd still be expecting misfires/ backfires and worst case scenario busted/bent valves

If all the tappets are pumped up then there will be no compression therefore no firing or backfiring.

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If all the tappets are pumped up then there will be no compression therefore no firing or backfiring.

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