Thread: Rough idling Disco

mine was rough shifting from second to first when coming to rest.

It seemed like it was idling a bit fast.

I pulled out the stepper valve, checked the winding resistances (50 and 51 ohms, good) and cleaned it. It was a bit gummy, oily deposits, so was the seat. First,I hit the valve with a WD spray equivalent, then an electronic cleaner, then WD again to lube. The seat I wiped out with a cloth.

took her for a run, Nice shifts to 1st

I wanted to strip down the plenum to clean it all properly, but one bolt is VERY stuck. WD'd and whacked on the head, but no better.

I'll leave that until next weekend and borrow a helicoil set just in case.

Stainless bolts might be nice there.

Gets even better don't it?

I use Moreys Upper Cylinder Lubricant & it is also an Injector Cleaner as well.

Works well for me.

http://www.moreyoil.co.nz/product.php?catID=11cat=Oils

mine was doing this bad shift down thing on petrol AND gas.

I reckoned (if it was an idle issue) it had to be either the stepper or the VSS. I'd habve to get dirty to check the VSS so I though I'd start upstairs

got to love it when it works out this way

4Bee thanks for the link. My EFI is no longer such a mystery

You're welcome. (How come you are using my wife's name as a user name btw?

I digress.

If you do tackle the VSS try not to do it laying on your back underneath. Due to bits in the way, you can't seem to get your arm/wrist combo to work as it should to get the setscrew out.

Also, it's Loctited in.


Using a pit or hoist would be much, much better. How do I know this?

My VSS came apart at the seam, which I mentioned ^ ^ ^, seems to be a common problem & as there is a rotating magnet inside, it seems to attract all the road s h i t e & I found magnetised particles jamming up one corner as it were.

Cleaned it all up & reassembled it with lashings of blue silicone & a cable tie.

It did tend to run better after this clean up & settled down to apx. 725 rpm once stationary.

It has been superseded to YBE100540 (old one is AMR1253) so maybe the problem was rectified in this SS. The busted seam problem was on GOOGLE searches on a few sites.

fortunately, my neighbour across the road has a pit and is happy to share

Can I have his phone number please?

Originally Posted by 4bee

Try this.

Remove the MAF multiplug & give the male flat pins a slight twist with some pointy nose pliers.

Apply some contact cleaner to the pins & female sockets & move the rubber boot back & ensure all wires are intact.

Replace & support the plug.

I chased this problem for yonks until I stumbled upon it one day, after it was running like a soleless Nike boot.

Fixed it, & it has never looked back since.

Worth a try.

Hey 4BEE, you just solved a long standing problem I have had with my '89 RR.
I have had an unstable idle for months now, even to the point of the vehicle rocking while waiting at lights...(how embarrassing!) Tried lots of things, new plugs etc...when I read your suggestion I went straight out and pulled the airflow meter plug off, gave it a good clean with contact cleaner and hey presto! Problem solved! It is so much better to drive now, so a big thanks to you.
Cheers, Pete.

Great innit? I'm not just a pretty faeces you know.


Obviously it won't fix all crook V8i idling problems, but it made such a remarkable difference to mine, I was waiting for it to pack up again. Of course it hasn't.


You are most welcome & thanks for the feedback.