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I have a 1993 Astra 1.4i (MULTEC M + cat). Engine code C14SE. It won't start. I've replaced the crankshaft sensor, the fuel pump, the engine temperature sensor and the plugs. All 4 plugs are firing (taken out of the engine and left connected to the DIS, lying on the rocker cover for an earth). There's pressure in the fuel rail (when pressing the Schrader valve). When removing the plugs after cranking, they smell of fuel but are not 'wet' (as, rightly or wrongly I expect them to be). Cranking produces an occasional 'pop' but no other sign of life. The timing appears to be OK (timing light held at the pulley). I'm left with the ECU as a possibility. Any thoughts, before the men in white coats come to take me away??? (The timing belt and water pump were replaced about 2000 miles ago).
Edited by Pugugly {P} on 24/01/2008 at 18:15
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Check the compressions, the exhaust back-pressure [take the oxy sensor right out] and the cam timing.
Dry the plugs with serious heat and try it with a squirt of brake cleaner into the inlet manifold.
What happened before it wouldn't start?
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Thanks for your response, screwloose! Compressions are: 175 on No 1 and around 150 on all the others (it's a rather old 'tyre gauge', crude type of tester). I'll do the other checks you suggest and report back. Many thanks for your interest. Before the non-starting era it would sometimes seem to be firing on only 2 or 3 cylinders for a short while when starting up, then suddenly pick up and run normally - thereafer it would run perfectly. Whatever was 'going' is now 'gorn', it seems to me! It's beginning to seriously pink fluffy dice me off.
Edited by Dynamic Dave on 24/01/2008 at 18:32
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Double-check the connexions in the coolant temp sensor plug; they get slack and don't make contact - very common fault. [Live-data has it's uses.]
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When cranking, is there anything coming out of the exhaust?, any flow at all?
It's not impossible, if the cam timing is or has been wrong for the exhaust rockers to break. You get spark, fuel, and good compressions. You get the odd fire, when you've had the plugs out, and have let some exhaust gas out of the cylinders, but it won't run. (I had this very thing happen with an 18SEH engine on a Carlton, and it took me a little while for the penny to drop)
To check for this, just take the cam cover off, it only takes 10 minutes to do.
Number_Cruncher
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Removed rocker cover. Cam seems to be operating all valves OK (at least, they're going up and down, and none of the rockers appear to be broken). Dunno about the exhaust pressure. I'm a bit reluctant to take out the oxy sensor (it's been in there since 1993!). I think the sensor itself must be OK cos the car passed its MoT only a couple of hundred miles ago. I've just, more in desperation than anything else, substituted a relacement ECU (bought cheap off ebay). Exactly the same symptoms. All 4 plugs are firing. Timing seems OK. There's pressure in the fuel rail (when pressing the Schrader valve - though I don't have a pressure gauge). Cylinder pressures are: No1 170, No2 155, No3 140, No4 130 psi. Not convinced there's fuel getting into the cylinders cos the plugs, although they smell of fuel after cranking, are not 'wet' as I think they should be(?). Cranking produces a semblance of 'firing' very occasionally, and sometimes a loud noise spmewhere between a 'pop' and a 'bang' followed by light grey smoke from somewhere (but before I get around to the engine to see where it's come from it's dispersed). Now desperate. Either it, or me, is destined for the knackers' yard!!! Any other ideas/suggestions very welcome!
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I would follow number crunchers advise, check that exhaust isn't blocked! remove sensor or slacken off front pipe. Have you checked cam timing to make sure it hasn't jumped. I would also check fuel pressure & is it fuel or water ?. You could try spraying can of carb cleaner down air intake whilst cranking & if it fires up you know its fuel related
Doc
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You have got a spark, fuel, and apparantly compression (but suspect they are not right somehow) . Therefore its a timing issue (cam belt ?) because if the other 3 happen at the right time it will start and run. Also with the pop/bang and smoke from under the bonnet = its firing at the wrong time and igniting fuel into the air filter I assume!
With it having run on 2 and picked up to 4 in the past I suspect valves, head gasket, and/ or cam belt/timing issues. the initial running on 2 and then picking up is a fairly usual sign of head gasket impending failure on these though!
Its fairly basic setup, not too critical of electrical wizardry etc. Has belt tension slipped? Tensioner packed up? Worth taking the covers off for a good luck.
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As Yorkie says; if it's backfiring, check the cam timing. The keyways can fret and the belt pulleys can move on the crank or cam.
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EUREKA!!! I was about to take the cam sprocket off, to see if it had 'slipped' wrt the cam when I noticed that both valves on No1 cylinder were shut (with cam and crankshaft set at TDC/compression stroke). Thinks: there surely can't be anything wrong with the timing, in that case. Then my eye wandered across to the DIS on the other end of the cam. Thinks: summat's obviously wrong with the 'firing order' coming out of the DIS module. I then checked the plug lead connections at the DIS. Yes, you've guessed it! The leads were on the wrong outlets. During fiddling I must have reconnected 'em wrongly. In fact, only cyinder No1 was correct!! It started up first flick and runs like a sewing machine again. Still, it's had a new fuel pump, crankshaft sensor and engine coolant tempertaure sensor (and I now have a spare ECU, a cylinder compression tester and a fuel pressure tester). It's a shaming experience! Thanks to everyone for all your help and advice, and my apologies for being such a pink fluffy dice
Edited by Dynamic Dave on 27/01/2008 at 20:56
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It ain't much of an excuse, but: the cylinders are numbered sequentially Nos 1 to 4; the firing order is 1, 4, 3, 2; the outlets from the DIS don't conform to either! They run (from the top of the DIS) 1, 4, 2, 3!! I must have connected them in the belief that the DIS outlets would be sequential from the top - hence only No1 was correct! An expensive lesson!? Thanks again to everyone for their help/advice.
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