Fault on number two cyl

I had a look at my sisters astra 14i (M reg 94/5) she was complaining about
using a lot of fuel - approx 15 miles to a gallon. It appeared to be running
on 3 pots.
So I checked to find out which one was off it appears to be number two,
anyway I swopped the plugs - still the same. I'm looking for something
simple, I don't want to dive straight into saying the engines shot. I have a
feeling it could be an injector but I don't know how to check these - any
help would be appreciated

Bill

 

what was the condition of the plug on 2? fouled? dry? whatever? how do you
know the plug is in fact firing?

pull the lead to that plug and fit it to one of the old plugs you removed
earlier. then rest it on the engine somehow andget a friend to turn it over
an check for a spark.

Mike

 

Yeah it was a bit shooty
I swapped number 2 plug and put it in 4 which proved the plug was not at
fault. The leads on the plugs are arkward to remove whilst engines running,
so I pulled them off one at a time from the dizzy. with/without the plug
swap there wasn't much difference in engine change when number 2 lead is
pulled off compared to leads 1 3 & 4

I will give it a go - over looked that it could be number 2 HT lead - cheers

bill

 

hmmmm. wonder if the injector might be stuck open. if you have no joy with
the HT lead, then see if you can swap 2 injectors round. I know its
buggering about, but if you do need to spend money on new parts its better
if you can pin it down precisely rather than just throw money at the
problem.

Mike

 

Have you done a compression test?

 

No - I didn't want to go that far just yet. (though its going that way) I
thought I'd check all the daft things first.

Bill

 

After another look I'm not to sure whether this is the injection model. It
was dark when I lifted the bonnet; it's my sisters' car. It looks like it
has a carb on but could this be single point injection? (though I'm not
fully Fimilar with injection models). I noticed the Lamba sensor and assumed
straight away it was fuel injection, now it's not so obvious.



Bill

 

It is single point injection if it has something that looks like a carb.

 

not at all daft. you check the simple things first.

Mike

 

iirc the single point injection models only had the Vauxhall and Astra
badges on the back of the car ... only the multi-point version had 1.4i
added. Of course someone could have added it later if it does have the
1.4i
badge now.

just a quick and easy check .. assuming I'm right of course

Mal

 

Thanks for that. Do I assume they work similar a carb then?

 

Looks like a single injection type then. Could this be faulty? Ive noticed
sensors all over the place could these cause this problem Ive got here?

Bill

 

If injector was playing up you would have misfire all over not just one
cylinder.
Will be - plug/lead/cap(if it has one) - compression - inlet manifold gasket
leaking. One of those.

 

Checked Plugs/HT leads/cap (interchanged) also the inlet manifold gasket
seems fine no leaks- looks like a compression test - when I get a tester.
I'm wondering if any sensors could cause this problem, I noticed theres
about 4 here and there.

Bill

 

thing about the sensors is that they apply equally to all the engine, i/e
not to individual cylinders.

Something you havnt mentioned is any history on this fault. has it been like
this for a long time? did it suddenly come on? if so, was there any funny
noises?
Apart from running rough (on 3) are there any other odd noises from the
engine? Absent answers to these questions, and bearing in mind what you have
already done, I would whip off the rocker cover and see if the valves for
that cylinder are opening and (more significantly) closing.

Mike

 

I can see where you are coming from mike. apparently it started one Sunday
(suddenly) - the car is driven daily so it was noticed at once (the rough
running) alone with an increase in petrol consumption, over the next week.
No new noises - the engine and cam sound quiet - its got me stumped - I
don't have a compression tester with a screw in - thread mines the old type
you have to hold it against the plug cylinder which to be honest isn't ideal
or long enough.

Bill

 

Seen these break a rocker arm before - usually an easy repair as new are can
be put in if you get someone to force valve down - arms are about £5 from a
good motorist shop - Vauxhall ones are £17ish

 

Never really thought of the rocker arm breaking ( I well and truely
overlooked this) I suppose if the rocker arms broken and not touching any
moving parts of the cam, there wouldn't be any noise.
In the past Ive had problems where one cam and rocker have been so badly
worn (obviously noisey) that the vehicle was running rough, with that
cylinder coming on and off.

I'll have to make time this week to pull the rocker cover off and
investigate further.

Bill

 

This is the sort of thing I had in mind when I suggested taking off the
rocker cover (not a big job). I'm also reminded of a Mk 1 cavalier 1.9 that
I bought in the early 90's. lovely car, but I got it dirt cheap as was only
running on 3. I ran it like this for about 2 months until I decided to have
that look that I promised myself I would do when I got the time. as soon as
I got the rocker box off, the cause was (I initially thought) as obvious as
a slap in the face. each rocker rested one end on the top of the camshaft
and the other end on the valve. they individually pivoted on a stud screwed
into the head, with adjustment made with a self locking nut screwed on the
stud. (8 valves, 8 rockers, 8 studs and 8 nuts. no rocker shaft )The inlet
on one cylinder had slipped about 45 degrees round and wasnt touching either
the cam or the valve. with a socket and T-bar I slackened the nut,
re-positioned the rocker and set the clearance. the engine ran like a dream
on all 4.....for about five minutes, when the rocker fell off again! looked
at it more closely and I discovered that the self locking nut had siezed on
the stud, and I was in fact adjusting the stud in and out, with no means of
locking it in place. New stud an nut and some thread locking compund was the
permanant solution.

Sorry to go banging on about some obsolete bollix which doesnt apply to your
engine, but I 'm occasionally given to such things, and if someone reads
this and remembers it in 10 years time then maybe it will be worth it.

Mike

BTW if you do have a broken arm and replace it as described, you really DO
need that extra pair of hands

 

Mike its good to hear about faults people have had over the years so you
don't have to say sorry here - I remember the 1900 cc MK1 Cav they were as
you say adjustable tappets - I use to do them with the engine running - I
welded some pieces of metal plate and covered the chain and cam sprocket to
prevent getting oil everywhere. (mind you it didn't do much good to the
feeler gauges) As time went on they did a way with the 1900 cc engine and
introduced the 2000 cc - which came with hydraulic tappets.

Just an update now, to where I'm up to - I've lifted the rocker cover now -
I then turned the engine using a 19mm spanner (bottom pulley) a couple of
turns the rockets of number two appear fine - I decided to run the engine
just for a *visual look* and the two rockers appear to be OK. Its starting
to look like a valve or piston. Though I'd appreciate anybody here to tell
me it could be something else.

Bill