The car is a Vauxhall 1.4 single injection mutlitec ( C14NZ X14NZ engine) Astra ( 4cylinder, 8 valves). Has served me well with hardly any problems., however over the space of a half day started to lose power to the point where really undriveable and difficult to start.
Feels as though its lost cylinders (but it hasn't) or timing is really badly off.
No codes are shown by the ecu.
Vauxhall diagnosed head gasket, so replaced head gasket (no evidence of failure), water pump, belts etc. to no avail. Local engineer had a go and replaced Lombard? sensor to no avail.
He managed to significantly improve running by advancing the distributor (timing), but still not right and obviously a bit of a botch.
To eliminate the obvious: Head gasket is definitely good. Timing belt is spot on. Coil and power transitor have been changed.
Other info: most recent repair was replacing Hal sensor in distributor (just used to cut out) but car ran fine following repair although distributor position required to be set a few degress more advanced.
Am i right in thinking that only the distributor and crakshaft sensors have a bearing on starting. Ie can I unplug the rest and motor should start ok.
This has so far defeated Vox and the local engineer any help would be greatly appreciated.
Edited by Dynamic Dave on 30/11/2009 at 19:11
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Has anyone checked the exhaust isn't blocked - eg, a partially collapsed cat convertor or the wadding in the silencer fallen in due to rotted baffle plates.
ps, the Lombard sensor is actually the lambda sensor.
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Need to correct a couple of things:
1. it is actually a X14NZ engine, no idea what the difference is?
2. It has no crank sensor, both injection and timing are driven from the distributor's Hal sensor via the ECU.
In response to dynamic dave, no one has checked the exhaust, not sure how you would go about that easily? Is there a clever way or is it a case of taking it apart and looking? Would one see the benefit in running by advancing the timing if the exhaust was blocked?
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The best way to check for a blocked exhaust,is to find a techie with a back pressure tester.This screws into the lambda sensor boss and will give a reading of good or poor pressure.hth
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Remove ehaust before the cat like at the manifold then will it start and run?
It will run don't rev it hard, if not have you checked the compressions?
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get someone to check the timming on the engine specifically the bottom sprocket (cam belt will have to be removed) the woodruf key tends to witter/break away allowing the timming to shift giveing power loss the bottom sprocket will have to be completetly removed to check thoroughtly,regards TB
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Isn't there a way of checking for a blocked exhaust with a vacuum gauge on the inlet manifold?
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If it were me, I'd just put my hand by the tailpipe and get someone to rev the engine. Very little ouput would indicate a restricted pathway.
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!!!!!The price goes to topbloke!!!!!!!
Having removed the crankshaft pulley and pulled the drive sprocket from the crankshaft the woodruff key has been completely worn away allowing the sprocket to rotate a few degress on the crankshaft. So although the timing marks say cyl 1 is TDC in it actual fact its not.
The slot for the woodruff in the crank shaft doesn't look too clever either. Is there a product that sets like metal to hold the key securely?
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I assume you mean "PRIZE"
as far as the state of the crank i am not aware of anything suitable, however the tightness of the crankbolt will be the deciding factor , makesure that the crankshaft is in the correct place, piston at TDC, new bottom sprocket on, belt on correct tension, covers on, then you need to put the bottm pulley on ond get the crank bolt done up as tight as you can, if you can get some locktight (this is a special glue for bolts) on the threads, you realy need to get this bolt what we call in the trade as FT so you realy need to lock the flywheel remove the starter motor and wedge a large screwdriver into the ring gear to stop the engine turning around as some one do's the crank bolt up with a large bar,Regards TB
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well done TB. Not extremely common & can be difficult to diagnose although advancing the dizzy was a bit of a giveaway.
I have seen this problem time & time again & have seen some garages spend hours diagnosing the fault. A TDC whistle in the plug hole is a valuble tool along with a vacum gauge. Can't beat some of the old gear!
Top marks TB
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While there, I would also be tempted to take the oil pump off to check if its drive from the crank is OK, or similarly damaged.
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