Revs drop when coming to a stop

I’ve noticed that when coming to junctions etc, the revs seem to drop right down, almost to cutting out point. Also if I slightly tap the throttle on tick over, the revs instantly drop to same near cutting out point. Any ideas on the cause? I’m thinking maybe a vaccum pipe somewhere, although not sure where to start looking?

Hi Chillax

Have you interrogated the diagnostics with an LED reader to see if any error codes stored?

Can’t remember if this was mentioned before. Get back if you are not aware of the LED diagnostic reader and what it can do for you - I will find instructions.

The other possibility I can think off is base idle - worth resetting that to see if any effect. Again can forward instructions if required.     


Mate if you could forward both that would be great! Not heard of the LED reader so very interested in the also.

This is the reader…

LED error code reader

It’s nothing special - I use a maplins 3p LED connected to a piece of bell wire and a bent paperclip as a jumper but probably wouldn’t have bothered if these were around when I made mine up:-)

Instructions are included but I will add the forum version(if I can find it) and base idle procedure and add to this post later. 

Forum error code reader instructions

Base idle adjustment  

Ok, have done the base isle adjustment using the guide (such a doddle! love working with old cars!) and that seems to have sorted it. Not had her out on the road since doing it, only up and down drive, but idle seems fine now, so no more rev dropping! Last time I had her out thouhg, got this really loud clunking noise when I pulled out of a junction. Sounded really bad, coming from N/S rear. Though either the halfshaft maybe, or the shocker or part of the suspension had come away, so drover her home very slowly (was only 2 miles away so not so bad). Jacked her up, and found the cause. The exhaust is hitting the rear subframe, due to the exhaust rubbers being completely shot. The one at the very rear of the backbox is totally cracked/perished and some clown has put a cable tie round it to try and make it tighter, rather than replace it! Been down to garage and bought new suport rubbers for the mid and rear sections, so will get them fitted this weekend. Hate bodges like that on a part that only costs a few pounds, no need for it imo.

Also ordered up an LED diagnostic code tester so can check and see if there are any faults that I havent noticed yet.

Thanks again for the info mate, so enjoyable being able to actually work on the car myself without needing to go to a dealer.