[Mk2] [NA] Eratic revs and now won't start

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Angie

[Mk2] [NA] Eratic revs and now won't start

Post by Angie »

Hiya I hope someone can help me.

I have a MK2 Rev 2 N/A and i went to drive it this morning and the revs were all over the place. The needle on the rev counter was just bouncing around all over the place and the car was juddering. I took him home and switched the engine off, tried to restart him but now he won't start at all.

Any ideas on what this could be? Could it be a misfire or is it something terminal and expensive? :(

Any help would be greatly appreciated :oops:

Thanks
Angie
shane1978
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Location: Shropshire
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Try these

Post by shane1978 »

I'd check all normal things such as HT leads , dissy cap, rotor arm, there is a thread in knowledge base for that.
Otherwise timing may be out. (ignition timing may have slipped?! or more probable the Cam belt slipped possibly? That would be new cambelt and tensioner and maybe bearings.
Say average cost for cambelt change is around £350, if you've had it done recently they should of checked tensioner to see if it was ok. Better just putting a new one on for the £60 and piece of mind.

Sure others will be along to tell me i'm wrong and put me right if i've made a mistake #-o

Its a starting point anyway!
Angie

Re: [Mk2] [NA] Eratic revs and now won't start

Post by Angie »

Thanks,

I had a cambelt change back in December when my cooling system got replaced so I really hope it's not that. I had a quick look at the leads but I didn't have time to look properly.

Just hope it's not too expensive :(
Leon.
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Location: Guildford, Surrey

Re: Try these

Post by Leon. »

shane1978 wrote:I'd check all normal things such as HT leads , dissy cap, rotor arm, there is a thread in knowledge base for that.
Otherwise timing may be out. (ignition timing may have slipped?! or more probable the Cam belt slipped possibly? That would be new cambelt and tensioner and maybe bearings.


If the timing is out it can just be corrected - timing belt and cambelt are the same thing AFAIK.

shane1978 wrote:Say average cost for cambelt change is around £350


Most specialists do it for £140-160, inc. belt :wink:

Angie, have a good check aroung the engine bay for things gone amiss. To suddenly go like that I'd say its not an ignition component suddenly gone west but I could be wrong. I'd say its more likely to be a hose come lose or something like that. Check they're all ok and that your jubilee clips are all tight. Check leads etc are all in place too, and you have nothing flapping about that could have worked lose!!

Good luck :)
Angie

Re: [Mk2] [NA] Eratic revs and now won't start

Post by Angie »

Thanks for the tips guys :)

I went to try and start it yesterday but the battery was flat so tried jumping it and the starter motor kicked in, and wouldn't stop! The car wouldn't start but it was just clicking so I took the keys out the ignition, disconnected the jump leads but the starter wouldn't stop! I had to disconnect the battery to stop it.

I have had it towed to the local garage (who changed the starter motor only a few months ago) to get it sorted. Could this problem have caused a drop in revs i.e starter motor draining the alternator?

Thanks
Angie
Pure

Re: [Mk2] [NA] Eratic revs and now won't start

Post by Pure »

sound like there may be a short in the starter motor would be drain the battery but ..dont know if that could be cauing the inital juddering
:-k
Angie

Re: [Mk2] [NA] Eratic revs and now won't start

Post by Angie »

Thanks everyone,

Car is now sorted, the starter motor got replaced and apparently the earth strap had come loose which was causing the erratic revs.

Just out of interest, can anyone explain to me exactly what an earth strap does and how it works?
Also, i got my car back yesterday and now when i start him up the engine management lights all come on and go off about 2-3 mins later. should i be worried about this?
JOHNM400
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Re: [Mk2] [NA] Eratic revs and now won't start

Post by JOHNM400 »

The earth strap is what it says basically. Its a heavy duty wire (sometimes braided) that earths the engine to the bodywork or the bodywork to the battery. Things like the starter motor and some of the sensors only have live wires running to them and pick up their earth through their casing being bolted to the engine which in turn is earthed to the body via the earth strap/s.

Your engine management light should come on with the ignition and go off as soon as the engine starts. If yours is on with the engine running then there is a fault somewhere and you need to pull the fault codes. Its easy enough to do and but the pins that need to be bridged in the diagnostic ports escape me. Should be in the knowledge database.
mr2neil

Re: [Mk2] [NA] Eratic revs and now won't start

Post by mr2neil »

turn ignition off, put a piece or wire between te1 and e1 on the diagnostic port rear drivers side of engine bay, turn ignition on(but dont start car), the orange engine light will then either flash on and off about once a second(this means there are no fault codes)
or will flash a set number of times then repeat, eg flash,flash,flash,pause,flash,longer pause,flash,flash,flash,pause,flash,long pause means engine code 31
it can sometimes gove multiple codes, and can be either single or double digit codes!!

dont forget to take the wire out! to clear the codes easiest way is dis the battery neg for 20 secs or so
best of luck
Angie

Re: [Mk2] [NA] Eratic revs and now won't start

Post by Angie »

Thanks everyone!

Well it seems to have stopped doing it now (hopefully)

Thanks again, I know where to come for advice, I really appreciate your help :)
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