Vague question.
Discussion
My cavalier has been giving me problems for some time now, in fact it's useless (see profile), but due to a financial nightmare (degree) I'm having to sell the escort.
Basically it frequently starts rough and if it does it'll break down within five miles, less if you try a hill or get stuck in traffic.
It always had petrol on the plugs after you break down, one of my plugs has turned brown for some reason, and I'm getting a big white spark instead of a small blue one like on Mum's cavalier.
Any ideas?
I've changed the entire electrical system (bar the coil, which I'm doing next weekend), the plugs, the dizzy cap, the rotor arm, the fuel pump relay, the HT leads etc.
I've cleaned the fuel filters (can't afford new stuff), its got a decent battery on it, the ECU light never comes on, (in fact none of the warning lights do) it happens in wet or dry conditions, with the car warm or cold (but most often when it's been stood for a few days) so I'm stumped.
Vauxhal want me to give them £600 to look at the damn thing 'thoroughly'.
Help!
Basically it frequently starts rough and if it does it'll break down within five miles, less if you try a hill or get stuck in traffic.
It always had petrol on the plugs after you break down, one of my plugs has turned brown for some reason, and I'm getting a big white spark instead of a small blue one like on Mum's cavalier.
Any ideas?
I've changed the entire electrical system (bar the coil, which I'm doing next weekend), the plugs, the dizzy cap, the rotor arm, the fuel pump relay, the HT leads etc.
I've cleaned the fuel filters (can't afford new stuff), its got a decent battery on it, the ECU light never comes on, (in fact none of the warning lights do) it happens in wet or dry conditions, with the car warm or cold (but most often when it's been stood for a few days) so I'm stumped.
Vauxhal want me to give them £600 to look at the damn thing 'thoroughly'.
Help!
Sorry bout the lack of info...
Engine is an 1987 2.0 multi-point injection, controlled by a multronic (I think) ECU.
The critical line I missed off my previous post is as follows;
I've tried running it on 3 cyls, does it fine. The spark is good and regular, but as I mentioned it is large and white instead of sharp and blue/violet like on Mum's car.
It just doesn't like idling. If you can hold the revs up it's fine (but coz it's an auto you can't hold the revs in traffic).
I don't know any make specific forums for cavaliers...
Engine is an 1987 2.0 multi-point injection, controlled by a multronic (I think) ECU.
The critical line I missed off my previous post is as follows;
Aside from the fact it breaks down so often it's absolutely fine. Not a single leak, uses no fluids, full, smooth power when running, no smoke out the back - ever, decent fuel consumption, no overheating, no funny noises nothing.
I've tried running it on 3 cyls, does it fine. The spark is good and regular, but as I mentioned it is large and white instead of sharp and blue/violet like on Mum's car.
It just doesn't like idling. If you can hold the revs up it's fine (but coz it's an auto you can't hold the revs in traffic).
I don't know any make specific forums for cavaliers...
Another bit I forgot to mention...
There is the occasional hiss when you take the fuel cap off, but I'd discounted it as a factor becuause the plugs were wet, which implied too much fuel, as opposed to a defecit.
The fuel return line is new, fitted by me only a few months ago. I guess that doesn't mean it isn't blocked tho.
The only other suspect bit is the 'fuel flow damper', a small thingy located next to the fuel pump at the back right of the car. It's rusted badly implying its very old. Does anyone know what it does, hence if it may cause engine flooding when it dies?
There is the occasional hiss when you take the fuel cap off, but I'd discounted it as a factor becuause the plugs were wet, which implied too much fuel, as opposed to a defecit.
The fuel return line is new, fitted by me only a few months ago. I guess that doesn't mean it isn't blocked tho.
The only other suspect bit is the 'fuel flow damper', a small thingy located next to the fuel pump at the back right of the car. It's rusted badly implying its very old. Does anyone know what it does, hence if it may cause engine flooding when it dies?
Its definately petrol on the plugs, and the coil has been in there for over a year (35K miles) so it's not the wrong one. The car has only once needed an oil top-up (though that was recently) 
I like the point about the coil going 'open circuit' when it overheats, could we have a bit more detail on that please?
I like the point about the coil going 'open circuit' when it overheats, could we have a bit more detail on that please?
Deltaf,
I have checked all the rubber pipes, they're secure and not blocked.
I'm very interested by your other suggestions, particularly this 'idle speed control valve', as the problem only ever occurs at or near idle.
I'll dig out the haynes manual and have a go at it this weekend.
Thanks for the input guys, I'll post again when I've had time to put some of this into practice.
I have checked all the rubber pipes, they're secure and not blocked.
I'm very interested by your other suggestions, particularly this 'idle speed control valve', as the problem only ever occurs at or near idle.
I'll dig out the haynes manual and have a go at it this weekend.
Thanks for the input guys, I'll post again when I've had time to put some of this into practice.
When it idles properly it aims at 500, but it's pretty steady. I thought about doing something to hold it higher but if it's not at very low revs the car won't engage gear, so that idea fell by the wayside.
I suppose I could try and inch it back up and see what point it refuses to work. IIRC it should be 750-900 rpm.
I'd rather fix it properly than bodge something though as I'll be using the car for business occasioanlly and I'd hate it to die at the wrong time!
Handy suggestion though, and could work well in conjunction with what deltaf was saying.
Hopefully I can give it a go on Sunday.
I suppose I could try and inch it back up and see what point it refuses to work. IIRC it should be 750-900 rpm.
I'd rather fix it properly than bodge something though as I'll be using the car for business occasioanlly and I'd hate it to die at the wrong time!
Handy suggestion though, and could work well in conjunction with what deltaf was saying.
Hopefully I can give it a go on Sunday.
mrsd said: Are you checking the plug to an earth point (such as the block) or looking at the gap ? If your getting a white spark looking at the plug, try it against the block and see what happens. If this gives a more normal spark, clean the plugs, check the gap and clean the HT lead contacts. Have you checked all the plugs ? Or only the one that's fouled ?
Was checking the spark against a cleaned off area of the block.
I've only checked the one plug (it wasn't the one that was foulded) as they're all pretty new and all the contact points in the dizzy cap have the same wear on them.
I couldn't pursuade my mate to help me check any more as he (rather foolishly) took the plug off the engine block before I'd stopped turning the car over.
Bzzzzzz.......
Hmm, a search in both the haynes manual and the engine bay have failed to locate an idle speed control valve, unless you mean the one linked to the inlet manifold by two 1/2 inch air pipes?
That looks like a sealed unit so I can't clean it. I can easily see how it could be clogged as one of the air hoses failed a while back. Could have no end of junk in there.
I've adjusted the idle speed (not very well). It now idles at 1300rpm when cold, and 900rpm at the lights in drive. It hasn't died yet, but as it's an intermittent fault that doesn't mean it's fixed.
Selects gear a lot faster tho...
That looks like a sealed unit so I can't clean it. I can easily see how it could be clogged as one of the air hoses failed a while back. Could have no end of junk in there.
I've adjusted the idle speed (not very well). It now idles at 1300rpm when cold, and 900rpm at the lights in drive. It hasn't died yet, but as it's an intermittent fault that doesn't mean it's fixed.
Selects gear a lot faster tho...
We seem to be on about the same idle speed control, it is the twin-pipe job. Mine isn't sealed any more as a pipe split before.
Er, system?
The engine is a mulitpoint injected 2 litre auto.
Where can I find out what system it is? All I gathered from the Haynes manual is that it isn't the Multec system as they're fitted on the single point engines.
In other news, the car has started every time since I adjusted the idle speed and just drove me 157 miles to guildford. Good start, but I havent exposed it to stop-start traffic yet. Or a hill.
Edited coz... Actually no excuse. I just can't type.
>> Edited by Alan420 on Thursday 3rd April 03:09
Er, system?
The engine is a mulitpoint injected 2 litre auto.
Where can I find out what system it is? All I gathered from the Haynes manual is that it isn't the Multec system as they're fitted on the single point engines.
In other news, the car has started every time since I adjusted the idle speed and just drove me 157 miles to guildford. Good start, but I havent exposed it to stop-start traffic yet. Or a hill.
Edited coz... Actually no excuse. I just can't type.
>> Edited by Alan420 on Thursday 3rd April 03:09
Right, the latest. This is wierd.
I reset the throttle rest so the car idles at 1300rpm, as high as it'll go whilst still engaging gears. This worked fine for a few days but now the idle speeds are dropping. It sits at about 800 as soon as you stop and falls lower the longer you stay stopped. Stalls at just under 500. Unless you put it in neutral - in which case it stays at 1300 and falls VERY slowly.
The rev counter's needle tends to 'hunt', waving up and down by some 50rpm, and inevitably falls. Occasionally a cylinder fires rough and that drops it quite a lot.
I hit rush hour traffic today with the girlfriend and had to stall the torque converter and hold it at 1500rpm on the pedal (embarrasing). That can't have done it much good but it was the only way to avoid grinding to a halt in the middle of Guildford (very embarrasing).
The other thing I've noticed is that it REEKS of unburnt petrol when you switch it off. I haven't had chance to get some carb cleaner yet, or a new coil. I tried the local scrappy for a coil today but they don't have anything that fits. Down to Halfords for some carb cleaner tomorrow (unless WD40 works? - student budget).
Does all this give a clearer picture of the fault or am I just confusing matters?
I really could do without buying another car right now...
>> Edited by Alan420 on Friday 4th April 01:46
I reset the throttle rest so the car idles at 1300rpm, as high as it'll go whilst still engaging gears. This worked fine for a few days but now the idle speeds are dropping. It sits at about 800 as soon as you stop and falls lower the longer you stay stopped. Stalls at just under 500. Unless you put it in neutral - in which case it stays at 1300 and falls VERY slowly.
The rev counter's needle tends to 'hunt', waving up and down by some 50rpm, and inevitably falls. Occasionally a cylinder fires rough and that drops it quite a lot.
I hit rush hour traffic today with the girlfriend and had to stall the torque converter and hold it at 1500rpm on the pedal (embarrasing). That can't have done it much good but it was the only way to avoid grinding to a halt in the middle of Guildford (very embarrasing).
The other thing I've noticed is that it REEKS of unburnt petrol when you switch it off. I haven't had chance to get some carb cleaner yet, or a new coil. I tried the local scrappy for a coil today but they don't have anything that fits. Down to Halfords for some carb cleaner tomorrow (unless WD40 works? - student budget).
Does all this give a clearer picture of the fault or am I just confusing matters?
I really could do without buying another car right now...
>> Edited by Alan420 on Friday 4th April 01:46
deltaf said: If it stinks of petrol, id make sure ive not got a leak frst mate!!! Dont wanna have an "incident"...
While all this is going on, theres no management light coming on?
BTW, "e" reg, im thinking its the older shape one yeah?
If thats the case it should be motronic injection on that. Ill go have a hunt for some info.
The car is the old shape.
Pretty sure there's no leaks, the lines are new. Did have a patch in the tank a year ago, so I'll check that later, but it's never left a puddle on the drive, aside from engine oil.
No warning lights have come on during any of this.
Deltaf,
I tried the carb-cleaner today, exactly as you recommended. Big improvement. Much smoother transition from idle to drive.
It still looses revs if I leave it idling though, from 1000 at startup down to 500, it still seeks around, but now it doesn't splutter and stall if I rev it. It just settles (very slowly) back to 1000 then starts to sink again.
It's use-able now, which is a big step forward, but sadly I'll have to leave it for a while.
For some reason my skin reacted VERY badly to the grime under the engine bay today (despite my immediate wash-off after work). My hands are in tatters so I'll have to wait till they heal up a bit, or at least stop bleeding so much.
Thanks for the checklist. I'll get onto that as soon as I'm able.
Cheers again everyone (Deltaf in particular). Thanks to this thread I have a working car again!
Now time for some
to distract me from the fact I can't bend my fingers!
I tried the carb-cleaner today, exactly as you recommended. Big improvement. Much smoother transition from idle to drive.
It still looses revs if I leave it idling though, from 1000 at startup down to 500, it still seeks around, but now it doesn't splutter and stall if I rev it. It just settles (very slowly) back to 1000 then starts to sink again.
It's use-able now, which is a big step forward, but sadly I'll have to leave it for a while.
For some reason my skin reacted VERY badly to the grime under the engine bay today (despite my immediate wash-off after work). My hands are in tatters so I'll have to wait till they heal up a bit, or at least stop bleeding so much.
Thanks for the checklist. I'll get onto that as soon as I'm able.
Cheers again everyone (Deltaf in particular). Thanks to this thread I have a working car again!
Now time for some
to distract me from the fact I can't bend my fingers!Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff