Club 80-90 Forums

So.... 1.9dg has gone through MOT with no advisories WooHoo! But.. engine is over revving. Have tried the idle screw and have given it a really good run out as has not been used for 6 months. Vac hose seems to be fine otherwise i guess wouldn't have made it through emmisions? I'm coming to the conclusion that either the choke is stuck on or the carb is sticking a bit? Not sure what other things could be causing it? when i force the accel cable further over the idle settles to a normal position but as soon as i release it goes back up to about 2000 rpm.
Any suggestions on where to start first?

Many thanks,

Matt.

Check where the throttle cable goes into the adjuster at the carb, you may find that the cable outer is sitting on the adjuster rather than in it.

Bit difficult to put into words but have a look at the cable and it will make sense.

Hope it's as simple as that for you.

A few points ^^ as he said ^^ the outer throttle cable not sitting right and pulling the throttle on slightly.

Can I ask you what have you been tweaking to adjust the idle speed? you should only be touching the large air by-pass screw and not the small mixture screw OR the throttle stop itself.

The pigtail on the by-metallic choke spring has broken allowing the choke stepping mechanism to move randomly.

Air leak...

However....by you description it does sound like a simple case of the throttle pulling so needs re-locating and a small amount of play introducing into the inner cable so the throttle can return freely to it's stop.

Martin

Hi Both,

Thanks for replies, I've checked the cable and it seems to be sitting ok.
It was only the big screw I had a go at turning, 1 turn each way to see if any difference but didn't affect it. I'll try giving the cable an extra bit to see if that does the job. Next obvious question is how best to introduce the extra into the cable? Is there an adjustment at peddle and carb ends?

Thanks,
Matt.

As martin suggests.. it reads like your autochoke & fast idle mechanism is sticking
liberally spray the mechanism with WD 40 and then a light oil... work the mechanism by hand until it moves freely.
]

don't forget the flap actuating lever


here's the whole mechanism with the carb split

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Thanks Kev for the info, those pictures were great! I have sprayed + oiled around the springs in the first pricture, i think this is where the problem is...

The spring on the right hand side has some play in it ie. the coils don't sit tight to the rod. I can't see where it's broken, was hoping that some slackness is normal (wishing really!) How many spanners is it to remove and replace?

I couldn't see a section in the haynes so not even sure what they are called???

once the carb is off you'll be able to see the spring locations
it's probably just come off the mount.

those pics clearly show the correct position for the spring mounting points

It's been a while since posting a photo, let's try this!?



The highlighted spring is the one thats loose, think my eyes are getting bad but can only see the one fixing point as highlighted in the photos?

I'll have to wait till wed's to have a proper look. If the spring has gone, is it the nut to the left that comes off to get to the assembly?

Thanks.

springs have two ends, here is the other end.
The left hand one is the other end of your arrowed one

Cheers Kev, perfectly clear. Will get out tonight and check those!

had similar problem....but mine was the accelerator pedal not returning properly...due to the fact that one of the pop rivets was no longer riveted! Pedal was twisting slightly and idle was high. A new self tapper and its been fine!

regards

Emma

Thanks Ermie,

I've checked that too but all seems fine. I'm still thinking i'm gonna have to replace the spring, I oiled the moving parts and seemed to be OK for a short time, it was a bit stiff though. I'm not convinced the spring has enough in it to pull it back? So i'm thinking if it's an easy job, replace the spring in the pic as it looks slack, give the mechanism a real good clean and hope when it's all back together it works!!

This all seems great, I've googled the spring but can't find it. Does anyone know what it's called and if it can be bought separately? And then is it just a case of removing the nut?

Thanks,

Matt.

Can see both ends of the spring are attached:



But it does look a bit loose...