Unexciting car with a bit of a problem... Diagnose
Discussion
I have a 1.6 litre Golf Driver.
It's done about 85k miles so is still pretty low mileage for a Golf built in 1990, but it's been having no end of trouble. I'll try and describe some of the symptoms.
Recently it devleoped a terrible misfire which got even worse in the rain. If left on the driveway to idle the car would initially tick over as per usual but the idle speed would then gradually increase over a period of about ten minutes to what sounded like 3000RPM! At this point the engine would be running way hotter than usual, of course. After another five minutes the idle speed and engine temp would settle down again graudally, although the car would misfire and splutter a bit as it did so. Any attempts to drive the car during this 15/20 minute period would result in huge misfires and more often than not the car would stall under anything but the slightest opening of the throttle. Incidentally, when starting from cold the throttle feels very 'thick' and not very responsive at all until the car gets settled.
Recently the dizzy, rotor arm and (probably carbon fouled) spark plugs have been replaced and the problem has lessened considerably. Never the less, the stodgy feel from the accelerator pedal remains, as does the misfiring (although it is less severe). The engine also sounds a bit ropey and never seems to actually settle down to a perfectly smooth idle...
I can't really give a better description than that I'm afraid. Is there any chance somebody could hazard a guess at what might be wrong so I can fix the damn thing and then sell it?
It's done about 85k miles so is still pretty low mileage for a Golf built in 1990, but it's been having no end of trouble. I'll try and describe some of the symptoms.
Recently it devleoped a terrible misfire which got even worse in the rain. If left on the driveway to idle the car would initially tick over as per usual but the idle speed would then gradually increase over a period of about ten minutes to what sounded like 3000RPM! At this point the engine would be running way hotter than usual, of course. After another five minutes the idle speed and engine temp would settle down again graudally, although the car would misfire and splutter a bit as it did so. Any attempts to drive the car during this 15/20 minute period would result in huge misfires and more often than not the car would stall under anything but the slightest opening of the throttle. Incidentally, when starting from cold the throttle feels very 'thick' and not very responsive at all until the car gets settled.
Recently the dizzy, rotor arm and (probably carbon fouled) spark plugs have been replaced and the problem has lessened considerably. Never the less, the stodgy feel from the accelerator pedal remains, as does the misfiring (although it is less severe). The engine also sounds a bit ropey and never seems to actually settle down to a perfectly smooth idle...
I can't really give a better description than that I'm afraid. Is there any chance somebody could hazard a guess at what might be wrong so I can fix the damn thing and then sell it?
EH.. probably not going to be alot of help here, but I'll try.
Is the coolant (and oil) level ok, does it use coolant or oil?
When you say the engine runs hotter than usual, do you mean that it rises very high on the guage, or just that the fan comes on at a bit hotter temperature than the guage normally shown when driving? -I thought the fan was coming on a wee bit later than it should when I first bought mine (Golf Mk3 1.8 8valve, dont know if its basically the same engine or not), however, everything that I have read regarding states that the fan should switch on at 105 degrees C -which is about what the gauge on mine shows when it does.
If the fan is not coming on, or if it is running alot hotter than it should then I would avoid running it in these conditions like the plague as you will cause more (expensive) damage.
Does the car have a carburetor or is it fuel injected? if it has a carb, then does the choke work correctly? -this I am thinking could be causing the increase in revs etc as the engine would be running really rich.
Also, assuming the engine has a carb (probabay at that age, though I'm not 100% sure), and most of the missfiring has gone away when you serviced it, then there is a fair chance that the carburation is wrong. This would be really easy to fix for someone who knows what they are doing. If you don't know anyone then have a rake through the local paper/yellow pages for someone who does car tuning.
What does a "stodgy" accelerator feel like? -does it just need a new cable?
Pete
Is the coolant (and oil) level ok, does it use coolant or oil?
When you say the engine runs hotter than usual, do you mean that it rises very high on the guage, or just that the fan comes on at a bit hotter temperature than the guage normally shown when driving? -I thought the fan was coming on a wee bit later than it should when I first bought mine (Golf Mk3 1.8 8valve, dont know if its basically the same engine or not), however, everything that I have read regarding states that the fan should switch on at 105 degrees C -which is about what the gauge on mine shows when it does.
If the fan is not coming on, or if it is running alot hotter than it should then I would avoid running it in these conditions like the plague as you will cause more (expensive) damage.
Does the car have a carburetor or is it fuel injected? if it has a carb, then does the choke work correctly? -this I am thinking could be causing the increase in revs etc as the engine would be running really rich.
Also, assuming the engine has a carb (probabay at that age, though I'm not 100% sure), and most of the missfiring has gone away when you serviced it, then there is a fair chance that the carburation is wrong. This would be really easy to fix for someone who knows what they are doing. If you don't know anyone then have a rake through the local paper/yellow pages for someone who does car tuning.
What does a "stodgy" accelerator feel like? -does it just need a new cable?
Pete
Distributor clamp tight and ignition timing correct? If it's an injection engine (doubt it, although I'm no Golf expert) it may be the dreaded idle stabilisation valve. If injection or carbed, could be something as daft as an air leak. If carbed, might be worth an overhaul of the carb, or a spare from the breakers (not a burnt-out car though).
I should have mentioned it's a carb engine. My mistake.
The oil has just been changed, I topped up with coolant recently too, so everything there should be fine.
By running hot, I mean the engine temperature gauge runs up to about 3/4 hot, as opposed to it's usual running temperature of 1/4 hot. It nthen setlles back to normal temperature after about 20 minutes.
I'm thinking it's choke-related but I know sod all about cold start systems. I hope it's not the carb!
The oil has just been changed, I topped up with coolant recently too, so everything there should be fine.
By running hot, I mean the engine temperature gauge runs up to about 3/4 hot, as opposed to it's usual running temperature of 1/4 hot. It nthen setlles back to normal temperature after about 20 minutes.
I'm thinking it's choke-related but I know sod all about cold start systems. I hope it's not the carb!
Sounds like more than one problem to me.
Speeding up deffo sounds like auto choke probs.
Misfiring could be ignition leads, air leaks, timing way off, distributor problems(hall sender touching the trigger etc), dizzy cap carbon brush(make sure its intact!)
Check the ignition timing first, make sure the dizzy isnt loose. Get a peice of wire and earth it down onto the engine, then fray the other end like a brush before running the engine and then going over the leads while looking for leakage from them,(the wire means you dont get a shock and any leaks show up really well).
If that all seems ok, get a can of carb cleaner and run the engine, while spraying the carb mounting faces(just a little, dont go mad with it), the vacuum hoses and the intake manifold gasket areas. Any air leaks here will show up as a rise in engine speed, and should be fixed before going any further.
HTH.
Speeding up deffo sounds like auto choke probs.
Misfiring could be ignition leads, air leaks, timing way off, distributor problems(hall sender touching the trigger etc), dizzy cap carbon brush(make sure its intact!)
Check the ignition timing first, make sure the dizzy isnt loose. Get a peice of wire and earth it down onto the engine, then fray the other end like a brush before running the engine and then going over the leads while looking for leakage from them,(the wire means you dont get a shock and any leaks show up really well).
If that all seems ok, get a can of carb cleaner and run the engine, while spraying the carb mounting faces(just a little, dont go mad with it), the vacuum hoses and the intake manifold gasket areas. Any air leaks here will show up as a rise in engine speed, and should be fixed before going any further.
HTH.
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