NS Dev
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| posted on 21/2/08 at 08:39 PM |
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return line blocked on injection car?
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!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Schrodinger
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| posted on 21/2/08 at 08:50 PM |
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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.
Keith
Aviemore
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NS Dev
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| posted on 21/2/08 at 08:51 PM |
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Fuel is spraying from each in turn, in the firing order, while they are installed in the inlet manifold.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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paulf
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| posted on 21/2/08 at 09:04 PM |
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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.
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omega 24 v6
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| posted on 21/2/08 at 09:22 PM |
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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.
If it looks wrong it probably is wrong.
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rusty nuts
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| posted on 21/2/08 at 09:22 PM |
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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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MikeRJ
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| posted on 21/2/08 at 09:29 PM |
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quote:
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.
Is it possible that one of the cam pulleys has moved relative to a cam? ISTR they are keyed on the XE, but that wouldn't rule out a key
shearing or being left out during a rebuild. Alternatively what about the crank pulley key shearing and it moving on the crank?
I have seen a couple of broken cams on XE's, but both were caused by numpties not tightening the caps down evenly when replacing them!
Unless it's really grossly overfueling, then I'd expect to to at least fire occasionally. Ditto a blocked exhaust, they will usualy fire
(and back fire!) but not run for more than a second or two.
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chrsgrain
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| posted on 21/2/08 at 10:12 PM |
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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
Spoing! - the sound of an irony meter breaking...
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bigrich
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| posted on 21/2/08 at 10:20 PM |
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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
.JPG)
A pint for the gent and a white wine/fruit based drink for the lady. Those are the rules
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chrsgrain
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| posted on 21/2/08 at 10:23 PM |
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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
Spoing! - the sound of an irony meter breaking...
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MkIndy7
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| posted on 21/2/08 at 10:24 PM |
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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.
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chrsgrain
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| posted on 21/2/08 at 10:28 PM |
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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
Spoing! - the sound of an irony meter breaking...
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MkIndy7
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| posted on 21/2/08 at 10:36 PM |
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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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bigrich
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| posted on 21/2/08 at 10:42 PM |
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quote:
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
So long as its a good earth and tight it will be ok anywere,
I think a compression test is required.
Has this engine run before or is it new to you, compression should be around 180 psi on all cylinders
A pint for the gent and a white wine/fruit based drink for the lady. Those are the rules
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chrsgrain
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| posted on 21/2/08 at 10:47 PM |
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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
Spoing! - the sound of an irony meter breaking...
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02GF74
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| posted on 22/2/08 at 08:47 AM |
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quote:
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
if in doubt, get a separate bit of wire and connecto to negative terminal of battery.
what spark plugs are you using? do you have a set that worked with the eninge? (I recall buying some fancy plugs (platinum?) for my aster gte and it
wold not run well at all; fitted bog standard champions and all was fine).
have you checked you have good earths to the ecu and coils and measured voltages?
when you view spark, is it a nivce fat blue spark and hear a "crack" when it fires?
disconnect the fule pump and spray easy start onto the air filter - you should hear an attempt at fiting, if not, it is igniton at fault.
good luck
(should have fitted a simple crosflow!)
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rusty nuts
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| posted on 22/2/08 at 07:04 PM |
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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 ?
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NS Dev
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| posted on 22/2/08 at 07:26 PM |
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ahhh good one!!!
Thought of low oil press but not high!!!
now that is worth a check!!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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omega 24 v6
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| posted on 22/2/08 at 11:20 PM |
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If the followers are jacked up then I'd still be expecting misfires/ backfires and worst case scenario busted/bent valves
If it looks wrong it probably is wrong.
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rusty nuts
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| posted on 23/2/08 at 01:54 PM |
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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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omega 24 v6
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| posted on 23/2/08 at 02:09 PM |
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quote:
If all the tappets are pumped up then there will be no compression therefore no firing or backfiring.
I agree on no compression there will however still be fuel and a spark and an induction/exhaust stroke albeit with no compression so some sort of
explosion should still occur IMHO
If it looks wrong it probably is wrong.
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