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Re: Mike and James' 1993 Cavalier CD

Posted: Wed Jan 04, 2017 5:37 am
by ilovedmymantas
Not so sure about a new cat.
I've had the same problem twice (years apart). Both times replacing the lambda sensor cured it.
Other than that I'd check the exhaust manifold for cracks or gasket leaks- as per Robsey's observations.

My mot this month. I think It's going to hurt :cry:

Re: Mike and James' 1993 Cavalier CD

Posted: Wed Jan 04, 2017 12:04 pm
by James McGrath
I replaced the lambda sensor about 18 months ago with a BOSCH part.
It's possible that it could have failed in that time but I think unlikely.

Re: Mike and James' 1993 Cavalier CD

Posted: Wed Jan 04, 2017 7:55 pm
by cavalier1990
Robsey wrote:From reading into this.

Lambda is ideally 1 +/- 0.01
Below 1 is considered rich.
Above 1 is considered lean.

So your Lambda is indeed reading lean, which could well indicate an air leak before the test probe.

Assuming you car is a cat equipped injection, I would expect the CO to be 0.3% or a little less.

Non cat versions are 1% or less.
The hydro carbons are nice and low though.
Out of interest, and to give you some comparison figures James, I checked the old MOT's on my diplomat and each time seems to fail on the first fast idle on CO (0.37%) but 2nd reading ok (0.24%). Lambda is around 1.004 - 1.010 for first and 2nd high speed test respectively and natural idle CO = 0.01%, sheet says less than or equal to 0.5% for CO at natural idle and less than or equal to 0.3% for fast idle. HC all in the 10-20 ppm range.

Not sure if that helps any just to give an idea of maybe range it should be in.

Re: Mike and James' 1993 Cavalier CD

Posted: Wed Jan 04, 2017 9:24 pm
by Robsey
James McGrath wrote:I replaced the lambda sensor about 18 months ago with a BOSCH part.
It's possible that it could have failed in that time but I think unlikely.
Hmm - I made the same mistake three or four years ago.

My first sensor lasted 18 yrs.
My second one - a Bosch item from LMF Vauxhall lasted 18 months.
But that was on a C18NZ.

I have made two major mistakes with my Cavalier - both were not believing that a new part could fail in a short period.


So recommendation is get the back box sorted first - then consider other options after that.
For info, my Cat is still the original and was still doing fine at the last MOT at which it was tested.

Re: Mike and James' 1993 Cavalier CD

Posted: Thu Jan 05, 2017 10:03 am
by James McGrath
Yes, I'm keeping an open mind. The hydro carbons are up from last year (from memory I think it got about 20ppm) so the O2 sensor could still be at fault.

As for the cat, it was replaced 2 years ago but I think the wrong part was fitted as it looked much smaller compared to the original. It also never quite felt as lively as before. I'll be glad to get rid of the thing even if it's not at fault.

Re: Mike and James' 1993 Cavalier CD

Posted: Sun Jan 15, 2017 8:57 pm
by James McGrath
Well in the end my Father and I swapped cars; he took custodianship of the Diplomat while I was left with the CD enabling me to sort out it's MOT problems and one or two other jobs as well.

I decided t take it to the same place that did my V6's exhaust, Classic Custom Exhausts in Hastings. They confirmed for me that the catalytic converter was indeed a bit naff and probably the wrong size and that the rear box had turned into something resembling a colander playing havoc with the emissions.

I decided not to try and track down genuine parts as the garage said they could get me pattern parts that were at least as good quality as the originals and get them fitted the next morning. So I did exactly that.
I turned up the next day at 9am and by 10:30 it was all ready for her MOT retest.

Here's the new back box. Looks allot more substantial than the regular pattern rubbish, hopefully it will last a bit longer that the last one did:

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And the new Catalytic converter, also a good quality part by TPcats:

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After that it was time for a spirited drive up to Maidstone for the MOT re-test.
It certainly sounds much better now and seems to be more lively in the mid to high RPM range.
After putting it thought it's paces it passed emissions no problem and thankfully I left Maidstone with a clean MOT sheet.
Mission accomplished. :D

My Father uses this car for work and I'm normally working on weekends when he's not, meaning like ships passing in the night, I rarely get to drive it or have the opportunity to work on it. So I had a few jobs lined up that I've been meaning to do for ages.

For the last few years the car has been fitted with some awful cheepo aftermarket wing mirrors which rattled when the engine was idling and when you closed the doors. I changed these over for some genuine ones from my spares.
I didn't take any photos of this though.

Next thing was to get these on:

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These are rare as hens teeth these days and in my opinion far better than the plastic ones that replaced them.
I felt a bit guilty fitting them but finally came to the conclusion that they are only going to gather dust and that keeping the sills free from rust is more important than keeping the mud flaps in their original packaging.

Front ones fitted no problem:

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Technically the rear ones are the screw in type for an Astra but when we bought the car these are the type that were fitted (Well one was anyway) so it had the screw holes drilled into the bumper already:

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The first and second mounting points line up just fine but the third overshoots the bumper.
The way they were originally fitted was simply to put a screw right through the middle of the mud flap and into the bumper.
Obviously I didn't want to do this so I got some of these cheepo clips from eBay to act as a third mounting point and make them much more secure:

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Initially the bolts were far too long:

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But 30 seconds with a hacksaw later...

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... they fitted like a glove:

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Before:

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After:

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They look a bit far down to me in these photos, especially the front ones. They are installed according to the recommended heights but I may adjust them later.

I do have a set of proper Cavalier rear mud flaps and another set of front ones. These I'm keeping these back though in case the LS ever needs them:

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Next job was to give the ignition system a bit of a refresh.
I noticed the distributer was completely knackered. It didn't seem to have any effect on the way the car drove but the inside of the connectors were all corroded and removing the HT leads revealed copious amounts of green copper oxide powder.
So I fitted a new distributer, rotor arm, Bosch HT leads and a new set of GM spark plugs for good measure.
It was cold, dark and raining so I only got these photos from when I fitted the HT leads:

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It's been fun driving her. It's surprising how different it feels compared to the Diplomat considering that, apart from a few less toys and being a hatchback, they are essentially the same spec with the same engine, gearbox etc.

Here's a few scenic photos to end on:

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Re: Mike and James' 1993 Cavalier CD

Posted: Sun Jan 15, 2017 10:38 pm
by Robsey
All good work there James.
Not a fan of those U shaped flap clamps.

I used to find that they would stretch and open up over time, causing the mud flap to slip or droop.

Can't beat a good servicing to improve a Cav.

Re: Mike and James' 1993 Cavalier CD

Posted: Mon Jan 16, 2017 2:00 pm
by James McGrath
I'm not a fan either really.
They always rust and after a while you can't adjust them.

Better than screws though.

Re: Mike and James' 1993 Cavalier CD

Posted: Tue Jan 17, 2017 1:05 am
by Robsey
Anything is better than drilling or screwing through a perfectly good bumper skin.

Hmm - I think we need to look into, design and patent a better fixation method.

Loving the paint colour in those pictures.
Very nice natural lighting effects.

Re: Mike and James' 1993 Cavalier CD

Posted: Tue Jan 17, 2017 6:26 pm
by James McGrath
I like the bracket solution on the regular Cavalier rear mud flaps, just a shame that wouldn't work on the front.

My new camera certainty has much better colour accuracy. My old camera was a bit weak on reds making them look more like pinks.

Re: Mike and James' 1993 Cavalier CD

Posted: Thu Jan 19, 2017 1:05 pm
by Lowrider Dave
Good work James!

Re: Mike and James' 1993 Cavalier CD

Posted: Sat Apr 01, 2017 9:29 pm
by James McGrath
Over the cause of the last 6 months or so this car has had a terrible hesitation issue. It would seem fine under light throttle but would not accelerate under medium of heavy applications of the throttle. The effect would vary and sometimes it would seem fine and others become a genuine danger on the road, for example pulling out of fast junctions only to find you've got no power.
This last month it got allot worse, so for the last 2 weeks my Dad has been taking the Diplomat to work. This meant I had to use the V6 as an every day car, not a good thing on the fuel bills I can tell you! It's fine on a run, but when you are just doing 4 mile/10 minuet journeys to work it's pretty thirsty; managing just 200 miles on £40 worth. :shock:
Anyway, I digress.

I've been systematically working through a list of things it could be.
I swapped the Ignition coil over with a spare,
swapped the mass air flow sensor with a spare,
fitted a new water temp sensor,
fitted a new fuel filter,
fitted a new crankshaft sensor at significant expense, (I really thought this could be the problem as I had a fault code come up for the sensor on a paperclip test but it made no difference)
as well as the spark plugs, rotor arm, distributor and HT leads I fitted before this problem started, I thought I had tried everything.

I was about to give up, swallow my pride and ask for help when today I thought I'd give it one last go and swap the fuel pressure regulator over with one from my spares.
Bingo! Problem solved!
Now it's running nice and smooth right through the rev range, with good throttle response.

I'm now starting to think this may have been the cause of the poor emissions I was getting at it's last MOT.

Anyway, glad it's finally solved, I was beginning to loose the will to carry on.

Re: Mike and James' 1993 Cavalier CD

Posted: Sat Apr 01, 2017 10:12 pm
by Lowrider Dave
Thank goodness you found the solution - it's always annoying when you've tried all those different things and suddenly something you try on the off chance works!

Re: Mike and James' 1993 Cavalier CD

Posted: Sat Apr 01, 2017 11:52 pm
by James McGrath
Indeed. I can live with problems, to an extent, if I know what they are and what is causing them.
However, if I don't know the cause is really bugs me.

Re: Mike and James' 1993 Cavalier CD

Posted: Sun Apr 02, 2017 1:49 am
by Robsey
Excellent news on getting the old jalopy sorted. :cool

I know exactly what you are saying.
Known faults aren't a big worry.
But when you just cannot suss it out, it can really drive you bananas.

Thankfully Cavaliers for the most part are very straight-forward to fix.

I must admit, when you said that it was fine on light throttle, I immediately thought of fuel supply / starvation.
Exactly the same symptoms if you use a single point injector pump to run a multi point engine.
It will idle nicely and cope with light throttle - but give it any more and it splutters and hesitates.

Hmm - fuel pressure regulator... I will remember that for the future.

Had it been a carb engine, I would have considered vacuum advance issues.

Re: Mike and James' 1993 Cavalier CD

Posted: Sun Apr 02, 2017 4:58 pm
by James McGrath
Yeah, the thing which made me think it was ignition to begin with was that it would hesitate at low revs and it would sometimes be fine at high revs.
It was intermittent and very odd.

Reluctantly I'm going to order a new Bosch part and put that on there as the one I replaced it with looks very old and well used. In fact it looks worse than the broken one I took off, on the outside at least.
Can't believe how expensive they are though. £57.50 just for a valve. :shock:

Re: Mike and James' 1993 Cavalier CD

Posted: Wed Apr 26, 2017 6:42 pm
by James McGrath
I fitted the new Bosch part last week and all seemed well.
All hesitation was gone and throttle response was greatly improved.

Here's the new part next to the offending original:

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Fitted:

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Unfortunately, it has not lasted.
After a few days driving the hesitation has slowly crept back.
No way near as bad as it was but still defiantly there.
It happens at low RPM (below 1500) - put your foot down and nothing happens for a few seconds, then it jitters a bit, but once it eventually gets over 1500 rpm full power is restored and it runs fine. The hole event probably only lasts about 5 - 10 seconds.


Here's the new crank position sensor I had fitted a month or so back.
Another expensive part that didn't need replacing:

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In other news, some filthy little swine driving a 4x4 did this while my father was driving along a narrow lane:

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Apparently my Dad stopped to let the person through, but they didn't slow down at all and wacked right into it and then carried on going.
I only hope their mirror was just as badly damaged.

At least I managed to find a new heated mirror glass:

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Fitted:

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The scratch on the mirror casing will be harder to fix however:

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Re: Mike and James' 1993 Cavalier CD

Posted: Wed Apr 26, 2017 9:19 pm
by Mk3alan
Same happened to me years ago only the glass was ok but the case was busted - morons.

Alan