Advice on rough running MK2 Scala

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daveyheats
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Advice on rough running MK2 Scala

Post by daveyheats » Fri May 28, 2021 1:17 pm

Afternoon all,
Looking for some advice on the rough running of my MK2 Scala, specifically at low revs.

Over 3000rpm she runs much better (though still not perfect), but at low revs there's a distinct jerking, juddering and erratic acceleration where the car feels like it's struggling to evenly accelerate.

Just as a bit of background info, since buying the car I've replaced:
  • fuel filter
    air filter
    spark plugs
    HT leads
    fuel injector lines
    fuel injectors
    dizzy and rotor arm
    exhaust and rocker cover gaskets
    most if not all vacuum hoses
    replaced the fuel distributor with a better condition unit

Any advice on what I could look at next to improve it would be great.
My initial thoughts are replacing the ignition coil, and checking for any fuel lines that have perished / collapsed under pressure but I'd love any pointers.

Cheers!



daveyheats
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Re: Advice on rough running MK2 Scala

Post by daveyheats » Fri May 28, 2021 1:25 pm

Oh, and also on my list is to look in the tank and check the filler neck!



mark1gls
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Re: Advice on rough running MK2 Scala

Post by mark1gls » Fri May 28, 2021 2:06 pm

How’s the timing on the cambelt, check and double check as it could be 1 tooth out.

Have you checked the vacuum advance on the dissy, pull the hose off have if you suck on the hose you should see the insides of the dissy move.


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mark1gls
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Re: Advice on rough running MK2 Scala

Post by mark1gls » Fri May 28, 2021 2:07 pm

What fuel are you using, Super or normal unleaded fuel?


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
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daveyheats
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Re: Advice on rough running MK2 Scala

Post by daveyheats » Fri May 28, 2021 3:22 pm

That's really useful, thanks Mark. The dizzy's vacuum advance is a great shout and I'll look into that later today. Having read up on it, it certainly matches the symptoms I've been having.

Also on the fuel side of things, I've filled her up with BP's finest super unleaded.



daveyheats
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Re: Advice on rough running MK2 Scala

Post by daveyheats » Fri May 28, 2021 5:07 pm

Just checked and it's only moving literally a couple of mm when I suck on it, and nowhere near the full amount of movement it can do.

Does this sound like the potential culprit? If so, I just need to try and find another one now!



mark1gls
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Re: Advice on rough running MK2 Scala

Post by mark1gls » Fri May 28, 2021 8:34 pm

Just pop your to check mine and it moves a few mm.
I do have a video clip but not sure how to share it with you.

If you PM your mobile number I can WhatsApp you ?


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Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
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daveyheats
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Re: Advice on rough running MK2 Scala

Post by daveyheats » Fri May 28, 2021 8:49 pm

mark1gls wrote:
Fri May 28, 2021 8:34 pm
Just pop your to check mine and it moves a few mm.
I do have a video clip but not sure how to share it with you.

If you PM your mobile number I can WhatsApp you ?


Sent from my iPhone using Tapatalk
Have just PM'd you now chap :)



mark1gls
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Re: Advice on rough running MK2 Scala

Post by mark1gls » Fri May 28, 2021 9:05 pm

:-D


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
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daveyheats
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Re: Advice on rough running MK2 Scala

Post by daveyheats » Mon Jul 19, 2021 2:08 pm

Have replaced the vacuum on the dizzy with a new item and still having the same reluctant acceleration below 3000rpm.
Any other ideas where to look next?



RussGLAuto
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Re: Advice on rough running MK2 Scala

Post by RussGLAuto » Wed Jul 21, 2021 12:49 pm

Fuel neck, tank and lines for rust...


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daveyheats
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Re: Advice on rough running MK2 Scala

Post by daveyheats » Thu Sep 09, 2021 11:48 am

Just as an update to this, (having replaced everything else) and spoken to a mechanic, it's looking like it's the exhaust manifold that is most likely causing the issue.



mark1gls
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Re: Advice on rough running MK2 Scala

Post by mark1gls » Thu Sep 09, 2021 6:43 pm

Let us know how you get on.


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323