What might be causing the engine to race on my 1986 Renault Trafic campervan (petrol)?

Question

It's just come back from the garage after having a leaking water coolant pipe replaced. On the way home the revs took ages to slow when I eased off the accelerator and dipped the clutch. By the end of the 20 minute journey it was racing so bad that I could pull away without touching the pedal.

Thanks to everyone who answered. Took the van back to Renault today. It was a sticky throttle - they sprayed the throttle arm(?) with WD40, manipulated it a bit and cured the problem! (This was after I drove the 4 miles to the garage at 40 miles an hour without my foot on the accelerator - scary)

Answer 1

choke stuck? if they been under bonnet or engine area the accelerator cable may be sticking, if in doubt take it back to the garage and tell them its only been like that since u picked it up

Answer 2

I had a Renault 22 some years ago with the same problem, turned out to be a manufacturing design fault, the carb is not a good one and is not in a good position for cooling, when the carb got hot the choke and throttle butterfly's on the carb would stick because of heat distortion, i solved the problem by replacing the carb with a much better webber conversion and never had the problem again, there used to be a large pipe that came from the radiator fan that directed air at the carb to help with cooling, check if this has been disconnected.

Answer 3

Just been worked on, then an air pipe connected to the carburettor / throttle body or Manifold has probably come off, either right off or just enough to admit air, little beggars smaller dia than a bic biro, listen for a sharp hiss under the bonnet, better still take it back and let the garage do it.
alternatives are air filter or hose or pipe preventing throttle shutting but displaced hose more likely.
Mnifold or carb leaks unlikely bearing in mind car has been worked on and presumably neither carb or manifold disturbed

Answer 4

Jammed throttle cable, Take off the air filter and spray the Linkages on the Carb and the cable with WD40. pump the accellorator, (engine OFF) and repeat .

Answer 5

Check the air-filter & connections thereof, mon ami.
It sounds like it's getting too much gas & not enough air.
Also twiddle with the tick-over setting, and check the carb jets.
Give them a good blow-out
Or there again, it might just be a frayed sticky throttle cable.
Best of luck.

Answer 6

Carburation problems, needs adjustment with petrol mixture I would say, or the accelerator wire is sticking, spray WD40 around the cable ends, heres hoping.

Answer 7

check for a vacuum leak at manifold or carb.

Answer 8

sticking throtle cable or cab want adjusting