Erratic idle flickering between 800 and 1400 rpm.

[Dave_C]

I've got a 1990 (H) 480 ES and have just had work done to get a new MOT.

I had very erratic idling and the mechanic thought it was firing on three - subsequently he stripped it down, sorted the valve timing, ground and reseated the valves. It goes like a rocket now, but is still a bit lumpy under 2000 revs, and the erratic idle, although better is still flicking between 800 and 1400 revs.

Does anyone have any ideas?

Also, I needed a new air hose (the one between the air filter and engine - the black concertina one) and got one off a similar age motor in the scrappy - wrong one... I tried another - same again.

Both were much longer than the one on my car, and I checked a couple of photos on the old forum of 480 engines - which were different than mine.

Were there any variations in engine size/type?

Any help would be welcome - I might even be able to take a photo and upload it.

Dave - New 480'er in South West

[dragon]

I had very erratic idling and the mechanic thought it was firing on three - subsequently he stripped it down, sorted the valve timing, ground and reseated the valves. It goes like a rocket now, but is still a bit lumpy under 2000 revs, and the erratic idle, although better is still flicking between 800 and 1400 revs.

Does anyone have any ideas?

Idle ranging can be due to your idle valve (or anti idle valve if it's broken! ) being worn or defective. It is known to get gunged up with sooty substances and thus caus it's operation to be impaired - might be worth having a look at this, also checking it's wiring connections. From the old board:

quick fix for the idle speed valve.
take it off, spray WD40 down it, & twist it vigourously until you here the paddle inside moves freely, & makes a nice clicking noise, then just put it back on.
PS. can't guarantee how long this will last, these things only draw air through them, and it's basically the dust that stops them working.
also, down at the scrapyard they're fitted to just about any renault with fuel injection.
good luck

The idle valve is a black or silver cylinder infront of and just below the spark plugs as you look at the front of the car.

Good luck!