1992 Vauxhall Astra 1.4I 8v SOHC (1992 110,000 miles)
Hi – new to the forum so please go gentle with me. I am not a professional mechanic and do DIY through necessity not enjoyment and consider myself reasonably competent although this little tale may prove the undoing of that!
The above car has been in the family seven years and has just been handed back by No.1 son – it has seen him through university and he wants a proper car! Needless to say he has not really looked after and No.1 daughter who is 17 in January is the next candidate ‘owner’.
On initial running checks noticed engine running cold as indicated by dash temperature gauge. Verified with infra red thermometer that gauge was accurate and engine was indeed running cold – and therefore diagnosed thermostat as duff. Consulted Haynes manual (my only source of technical reference) and the dawning realisation that this was not going to be a 30 minute job (took me less than this on my W124 Merc). Purchased the stuff – thermostat, new cam belt, cam cover cork gasket and a water pump setting tool !!!!. Completed job after also changing water pump and the back hose because I thought I have gone this far – I do not want to be going here again soon!
Had a bit of fun (not) farting about getting the cambelt tension correct and got the whole lot together after also changing engine oil/filter and recharging coolant circuit with 50/50 antifreeze mix.
Engine turned over fine by hand without resistance (turned over many times while doing belt tension). Attempted start – engine cranked but did not fire!! (Eeek).
Turned engine over by hand so that camshaft at TDC for No1 power stroke – checked timing back on crankshaft pinion – Eeek crankshaft pinion was 1 or 2 teeth retarded. I do not know how the hell this happened I thought I had been scrupulously careful. I obviously had suffered a brain fart or something.
I have now reset the engine timing to spec. However engine cranks but does not fire.
Now it may be that this is a coincidence and something unrelated to the work carried out may be the cause and I will now investigate the obvious. Clearly my worry is that even with such a small error in engine timing I may have clattered the valves into the pistons even though there was no resistance when turning by hand.
I would like to avoid lifting the head for obvious reasons – is it worth doing a compression test?
I would be grateful for any technical advice and or opinions (Yes I know I’m a dumb ****). I am having a real crisis of confidence here. (Should I also replace the tensioner pulley assembly?).
Very many thanks in advance –this is a really great forum.
NormanB
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Welcome to the forum, Norma.
Earlier, I posted a question regarding a 1992 K reg Cavalier. Before doing so, I had done a search for any similar problems discussed on this site and came across the following thread:
www.honestjohn.co.uk/forum/post/index.htm?v=i&t=23...9
where someone was experiencing difficulty satrting a 1.6l SOHC engine. I would hazard a guess you could have a similar fault.
Please let us know how if that works and you get it sorted.
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Welcome to the forum, Norma.
Oops, sorry for the typo, NormaN!
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Hiya Norman,
Not sure if same applies to cam timing on cars, but a few years ago while working on a 4 stroke motorbike, I got the cam timing 180o out of alignment. No amount of kick starting or bump starting would get it to start. Occasionally it would fire, but thats about it.
First thing I would do is make sure the cam timing is correct. BTW, cylinder No1 is at the distributor end of the engine. Just thought I'd mention this in case you were trying to set TDC using cylinder No4 by mistake.
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TDC 1 + 4 will be the same. As the distributor is keyed into the cam you will not have the timing out 180 deg unless you have fitted the leads incorrectly or the cap the wrong way round (unlikely). It is also unlikely that you have damaged the valves by being one or two teeth out so I suggest that all that has happened is that the hydraulic valves have pumped up a bit and all the valves are off their seats. Solution is a bit barbaric but simply make sure that the battery is well charged, floor the accelerator to clear the flooding and continuously crank the engine until it is running. Hold the revs at 2000-2500 until it is running cleanly on all cylinders then run up to temp, add a flushing additive and change the oil. 3.5litres 15w/40 semi synthetic.
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TDC 1 + 4 will be the same.
D'oh, of course they are. Silly me.
As regard to cam timing being out, the bike I was working on was a single cylinder (Yamaha XT350) so that was why I was unsure if same applied to 4 cylinders or not.
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Hi again – update time:
First of all – thanks for the replies thus far.
MB – Useful thread, I have read and saved for future reference.
Dynamic Dave – Thanks for the input but am confident I have timing right and btw No1 is at the timing belt end of the block.
Andrew – Thanks for a great response – very useful. As you will see from my update below things looking good on there being no damage to valves etc as you forecast. I do not understand the valves ‘being off their seats’ but as I have done compression test now, I suppose that is now overtaken by events. I have not attempted a start yet but will follow your routine. Can I ask a specific question of you? I am not sure about fuel pump now – when I turn key I cannot hear pump running (have lifted seat/carpet flap/and covering shield) even momentarily. What do you reckon?
UPDATE
I decided to do a compression test even though engine would be cold because the delta between pots could still be a reliable indicator of problems.
Here are the results (No 1 being at the timing belt end of the engine):
1. 150psi (10.2 bar).
2. 136psi (9.25 bar).
3. 105psi (7.2 bar).
4. 132psi (8.97 bar).
Repeated test with 5ml of oil injected through spark plug hole onto piston of No 3:
3 170 psi (11.56 bar)
So it looks as though I have serious problems with respect to No3 cylinder bore/piston/piston rings.
Given the age of the vehicle (albeit it has A1 bodywork) it looks, as though this is an uneconomic basket case. Grateful for your expert views/advice. ( I really wish I had done this before I embarked on the other work!!)
Slightly depressed............
NormanB
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Dynamic Dave; btw No1 is at the timing belt end of the block.
Double D'oh!! Yes Norman, you're quite correct. Just had a look in the manual. God knows what I was thinking about by saying it was t'other end.
Re; compression check. Manual suggests the pressure difference between cylinders should be no more than 1 bar, so, yes, looks like No3 is suspect. However, a mate of mine with a 1.1 litre Fiesta ran it for over 2 years with one of the cylinders reading only 33% with the compression test.
Re; Valves. They are operated by hydraulic lifters. How long has the engine been stood without running? What might have happened is that if stood for a long time, the hydraulic lifters may have leaked their oil out of them and will need the engine cranking for some considerable time to build the oil pressure back up in them before the valves will operate again. I've known people who have had to crank the engine for over ¼ hour, and 2 flattened batteries, just to prime the lifters with oil.
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I wouldn't worry too much on the results of the comp test. As things improved with oil it confirms problem not caused by valve damage but is probably sticky rings which will ease with regular use of quality fuel and occasional use of a fuel system cleaning additive such as Texaco or Forte plus of course the aforementioned motor flush and oil change. With the results you have had from the compression test I cant really see any reason why she don't fire up, assuming that the cam timing is correct, ignition side of things are in good order. Regarding the fuelling side, You may have to give the engine a little burst on the starter to get the pump to run and then it will only run for a second or so as the ecu is not seing a running engine it will shut it down again... I am also assuming ( dangerously )that you have checked that you still have a spark since carrying out the work?
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hi
here is what i think you should do to get it started
same principle as a lawnmower (i know a car is different)
crank the engine for about a min
take the plugs out one by one and squirt a little fuel into the cylider,
when you have done all the plugs
make sure there is nothing parked behind you're car
start the engine
if it starts and stalls its a fuel problem and you have succesfully found the problem
hope this helps
James Stephenson
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Following the same line of thought....
If that doesn't help perhaps the way to prove fuel but no spark is to get a friend to crank it over and try and light the exhaust fumes with a match.
That should do it.
;-)
MM
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Norman
Another thought - you have checked that no wiring or connectors under the bonnet got accidentally disconnected when the work was going on?
Regards
John S
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Ditto. Norman has not made clear whether there is a lack of spark or is it a fuel-pump problem?
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Hi Chaps - what a great set of responses, I am truly grateful to you all.
Response (and 2 questions) to Andrew Moorey (Tune-Up): Yes, thanks Andrew. I am actually less depressed now about the low compression reading and had figured that it could only improve with a warm engine when \'things\' expanded to their working positions. Your reply however was a good confidence booster and I note what you say about helping matters by using fuel cleaning additives. In fact, I had prior to the timing belt end work run a Wynns flush procedure on engine lub side prior to a \'hot drain\', oil and filter change. However, had not addressed the fuel side.
Qtn 1: Will something added to fuel really sort out piston rings or do I need something a bit more direct/aggresive i.e. into the cylinders - any thoughts/advice here?
Thanks for the tip on the fuel pump and relationship with ECU, I now understand. I must confess I have not tested if I have a spark yet..and heres my associated question:
Qtn 2. Is it safe to do this by grounding plug on block with all these electronic malarkey thingies that these cars have?
Response to james_60: Great thanks James, I will bear that in mind. I have printed out the whole thread!
Response to MiddleMan: Yeah right, there is a name for people who light their exhausts :-)
Response to John S: Thats a very good point. I purposefully only disconnected 2 electical leads, the earth strap for the alternator bracket and the sensor (TDC -I think) bottom of engine. However, I may have knocked something as you say - so I will check.
SUMMARY UPDATE:
Not much actual progress (its been pouring down!) but I feel as though I have moved on in leaps and bounds in knowledge terms, thanks to you guys. As soon as I can - I will give it a good optical bollicking checking for any loose wires and then give it the \'barbaric\' treatment Andrew suggested in an earlier post.
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Answer to Q2: I think Haynes manuals advise you not to test for spark by grounding plug on block. If you live anywhere near the Tune-up boys (Andrew Moorey, et.al) why not ask thir price for diagnosis and call them in? I think HJ's FAQ has a link to their web-site.
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Hi Norman,
I think you are just a fraction away from a solution. My family have an Astra Sri 1990 and a Cavalier 1989 and I have carried out the procedure you have undertaken on both.
Some Checks to carry out:
1
Confirm all electrical leads moved have not been incorrectly remounted and inadvertantly been insulated.
2
Check No 1 piston on TDC (Remove spark plug) with the cam belt wheel timing marks correctly positioned and then confirm that the rotor arm beneath the distributor cap is aligned with the lead to No 1 piston.
3
Confirm that you have a quality spark. If Haynes disaproves of spark plug earthing on the cylinder head you may have to call in a mobile service engineer with Crypton diagnosis gear. I have used the earthing technique on my Astra without problems, albeit briefly, with my daughter turning the ignition key.
4
Confirm that the distributor cap is not cracked and that the carbon brush in the caps head is not worn out. I have experienced sudden loss of ignition when the plastic peg in the distributor that drives the rotor arm sheared on my Cavalier shortly after the engine was started. Your distributor may have evolved from my unit and not require one.
Every success
Julian Lindley
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Hello to everyone - A fine day at last!
Finally got around to getting to grips with the starting problem (post thermostat, water pump and cambelt change) and I wanted to close the loop with you all, especially all of those who offered me such sage advice.
What you all forgot was that you were dealing with an idiot!
Yes - I had spark and I had fuel but due to a major brain fart I had put the HT leads on with the correct firing order but counter to the normal direction of rotation! I really do not know what I had been thinking - what a t***!!
Anyway engine is now running as sweet as a nut, once engine had reached operating temperature, I left it running to prove electric cooling fan operation - all OK.
I then revisited the compression test with the engine hot - results as follows:
1 10.5 Bar
2 9.8 Bar
3 10.0 Bar
4 10.0 Bar
This would appear to be perfectly within specification and No 3 is no longer under suspicion. The conclusion is that doing a compression test while cold can only tell you state of valves/head/head gasket.
Once again thanks to you all for your help - this forum is a really super resource.
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