Hi all
I own a Mk3 Golf GTi 2.0 8v 95' N-plate, which has been running well since i bought it last July up until the middle of last week.
I filled my car up as i do every 2-weeks. Left the forecourt travelled up the road to work got less than a mile casually gazed across the dashboard, and noticed the fuel gauge rapidly decreasing. Naturally i pulled over at the next safest place. Looked around for a fuel leak none everything was fine, so i carried onto work.
Later in the day went out in the car had done approx 30miles and the fuel gauge is now showing 3/4 tank which was about right, thought no more it was now fixed.
Went out on Sunday had done a couple of miles and suddenly without warning the car stalled total loss of power. I tried to re-start it but nothing. Fortunately i was close to a halfords(for a plastic 5litre can) and a Sainsburys petrol station. So i got some petrol topped up the tank and the car started first time so i thought better get car home quick.
Got no further than 1/2mile and again it died, and wouldn't re-start so i called a friend and got a tow home. Soon as i'd parked the car on the drive i managed to start the car no problems. Bizarre.
Has anyone else had this problem or something similar or can shed any light on the matter i would be greatful. I'm sure both faults are related but how. Could it be a faulty earth?
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Paul
More likely to be a faulty ignition switch than a faulty earth.
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Check the condition of the wiring of the crankshalf position sensor after it is clipped to the block behind the oil filter head and front engine mount. The wire insulation hardens with age and crumbles away leaving 3 bare wires.
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Check important earth point situated under the battery, especially if a battery has been leaking. The battery has to be removed to get to it.
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Thanks for both bits of advice, i've just been home for lunch(live local) and to have a look at the car. The car started first time and remained running for a good 20mins before i switched it off. Left it for a while, and then failed to get it started. My dad suggested a faulty earth or corroded connection i'll have another look later.
Cheers
Paul T
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Paul
Next time it won't start; check to see if fuse 15 is live with the ignition on. [Or the black wire to the coil/amplifier.]
The contacts heating-up inside the ignition switches of Mk III Golfs is a well-known problem. Loss of feed to the gauges fits nicely with that possibility.
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Just one other thing on this subject. If i was to take this to the garage and by them using a fault diagnosis machine would they be able to found out from that if there were any earth/connection faults. How does fault diagnosis work?
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Paul
Could be wrong; but my gut feeling would be that this wouldn't be picked up by the ECU.
Just get it to stop and then do those quick tests and you'll be further ahead.
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Its saturday, and i've tested Fuse 15 once the ignition is on but not started and there is approx. 12.4v.
I started the car and let it run for 20mins and it stalled as it had done previously this time stationary. Then I tried to re-start the car and nothing totally dead. Left it for a further 10/15mins and it started fine, continued to run for approx 5mins, then without warning died.
Any further suggestion would be much appreciated.
Cheers
Paul
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I started the car and let it run for 20mins and
and there is approx. 12.4v.
Paul
There would be voltage there when it was working; try testing it again when it's cut out and not starting.
Could also be a faulty relay 30 [engine control relay] they suffer from dodgy solder joints inside. [Have a look.]
The fuel gauge dropping still suggests ignition switch contacts though.
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Right the ignition is on but the engine hasn't started and the instrument warning lights are on and the meter reads 12.38v.
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Paul
I'm clearly not explaining myself well. Test for that voltage.... when.. it... WON'T... start. [I.e. only after it's broken dow.]
IF the contacts in the switch are heating up and losing the ability to pass current; then testing them "cold" won't show anything wrong.
It's whether there is still voltage on that fuse once the engine has cut-out and is refusing to re-start that's important.
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You are explaining it perfectly maybe i'm not. I started the engine and left it running til it cuts out and can't be re-started, but leaving the key in the ignition with the instrument lights on (the car engine is hot) then tested the voltage using a Fluke Digital multimeter set to DCV, and at Fuse 15 the voltage is 12.38v. Therefore there is voltage on Fuse 15 when the car has cut out after being run for approx.20mins and can't be re-started (after it's broken down).
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Paul
Ahh; I'm with you now. Is fuse 15 shown in your handbook as the engine management feed fuse? If not; test the one that is.
I'm working on the tentative basis that this is an ADY or AGG engine. Yes?
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I'll have to get back to you tommorrow cos i've taken the car to my work (bigger working area) and now that it won't start can't get back home, consquently the owners book & haynes manual are there also, but i can confirm i have an ADY engine.
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I can confirm according to the Service Schedule book i have an ADY engine and also that it shows in the instruction manual that Fuse 15(10A) asthe engine management feed fuse.
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Paul
Than that looks as though it rules out the very common ignition switch fault. Try the fuel-pump fuse next time.
To use your meter to check for bad earths:-
Run the engine with lights; heater blower and HRW on. Measure the voltage between the actual battery negative post [the lead bit] and the body shell. Shouldn't be more than about 0.25 v.
While you're there; make sure any single earth/feed wires connected to the battery lugs are in sound condition.
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Thanks will do at next available chance. Sorry to be a pain but it's a more cost effective way than taking it to the garage if its something i can repair rather than them charge me for their labour and then any parts on top. Much abliged.
Thanks
Paul T
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I've just tried the fuel pump fuse as you suggested and there is no voltage there whatsoever 0.02v(dc), and that was when the car stopped with the ignition on as with Fuse 15.
Checked the feed wires these all look in good condition. Also tried running the engine with lights, heater blower and HRW on and the voltage between the actual battery post and the body shell read 0.03v(dc).
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Paul
Sorry; should have said "when cranking" to be certain on the fuel pump fuse. [It's only powered for a short time at key-on.]
Body earth reading is fine - no problem there. You could try the battery earth terminal to engine block as well, now that you're getting the hang of it.
If memory serves; the ECU earth is screwed to the inlet manifold or the end of the rocker cover; a bunch of brown wires - worth a look.
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I realised that when you test the fuel pump fuse that it only comes on for a short time and now understand why. I tried taking a reading while cranking, slighty uncomfortable but when i got a good contact it was 12.3 to 12.5v.
I did the earth terminal to engine block and got the same 0.03v reading.
Now with the ECU earth i've located two wires that are connected to an earth block with crimps, this is found on the engine below the head gasket and directly in front of it is the alternator mounting bracket.
The condition of the earth doesn't look to good there is blue colouring on the crimps indicating corrossion. And if you didn't know what crimps look like you'd swear there weren't any. The reading i'm getting here using a voltmeter across the battery negative post is 0.15/0.20v.
Should i renew these crimps/connections. I would probably have use a soldering iron to make an in-line junction with exsisting cables rather than trace them back?
I'm a Audio/Sound Engineer by trade so using a soldering iron and making up leads/connections is second nature for me.
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Paul
Any dodgy earth wires are always worth remaking properly. Even if it isn't the problem this time; they sound like a breakdown just waiting to happen.
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Screwloose
I've temp. run an earth cable between the battery neg post and a spare terminal on this engine earth block. And the car started within a minute of when it cuts out, instead of an 1-hour later.
But it still cuts out though it does start again straight away with no extra throttle needed.
Now what i propose to do next is take the two exsisting crimped ECU earth cables (presuming thats what they are)
make a joint between them and the temp earth lead, my question to you: Is that any different to what i've already just done?
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Paul
Remembering the misunderstanding about the fuse issue; it's obviously difficult to be absolutely sure we're singing off the same hymnsheet.
All Golf earths are plain brown; [except the few that aren't!] If these degraded wires are brown and bolted to earth; then probably the best move is to remake their earth as soundly as possible and try that.
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I will try that and report back to you.
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Screwloose
I've now improved the earth connections, and it has made a slight improvement but not enough for to want to drive it.
Once started it now runs for slightly longer. When it stalls the engine 9 times out of 10 will re-start a run for approx 10mins.
Just before it started to idle erratically (before stalling) i tried to keep it going by giving some throttle and i could hear a relay clicking on and off very fast it might be normal but it's the first time i've heard it as clear as i did.
Had a quick feel around and relay 30 is very warm more than the others. But i wasn't quick enough to find the one clicking.
Paul T
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Paul
Pop the top off and see if there's any sign of solder joint fatigue.
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Screwloose
Pop the top off what, sorry but i've been down the pub drown my sorrows.
Paul T
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Good Morning Screwloose
This morning went to local VW dealer picked up a spare relay 30 just in case only a tenner. Started car from cold to see how long it stays running before cut-out, all of 2-mins.
So I replaced relay 30 with the new one. The car started fine that was about 20mins ago and as I type it's just cut out, but an unusual thing happened before it died: It coughed and spluttered and dropped revs right before the cut-out point but it carried on running back up to normal idle speed for 30-seconds before finally stalling.
Must admit when I saw 2 magpies early this morning thought my luck was in maybe not.
Regards
Paul T
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Paul
Is the fuel gauge still dropping off before it cuts out?
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Screwloose
No its been working fine as far as i'm aware.
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Paul
Ahh; so that's changed too....
I think that as this has now become a straight cutting out fault; then the best next move is to get the fault-codes read. Falling gauges etc. were suggesting power/earth issues; without that, there's not a lot here to go on.
Identifying which relay was clicking might be useful though.
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Screwloose
I was afraid yoou'd say that. Spoke to a mate of a mate whose a mechanic(not where i normally take my car) quite local to where i live and he said to try cleaning the throttle body housing can that really make a difference.
Going back to fault codes i assume i would need to take it to a garage with diagnostics?
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Screwloose
Thanks for all your help on this thread, i understand a lot more about the workings of the car. I will have to take it my local garage to see if they can find the cause'.
Once i've sorted i'll let you know what the problem was.
Thanks again
Regards
Paul T
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Have you estabished whether you are loosing a spark? if not have you still got fuel pressure? are injectors still pulsing on cranking?They do have problems with an earth strap under the battery, I have also had one with a faulty fuel pump drawing too much current causing the relay to drop out. If the pump is drawing a higher current it is worth checking to see if fuel is returning to the tank as some times the fuel regulator fails causing excessive pressure overheating the pump or wiring to it!
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Did you note ggh1's post above re crankshalf position sensor.
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Yeah I had a look can't see any problems with that, checked all visible connections.
Thanks anyway
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Because the crankshalf sensor wiring is so inaccessible under the front engine mount I was unable to see it's condition. When I removed the sensor the first 2 inches ( from the sensor end) of the outer and inner insulation crumbled away when I flexed it in my hands, leaving 3 bare stranded wires. Replacement of this sensor cured my cutting out problems. Mk3 GTI AGG 1996 130,000 miles
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From my past experience it would seem that the sensor wiring insulation is of an inadequate specification for it's working environment. I would suspect the sensor wiring if it has been in situ for longer than 100,000 miles/10 years.
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