over revving

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
tomrostron
Posts: 17
Joined: 13 Nov 2008, 11:22
Location:
My Cars:

over revving

Post by tomrostron »

my rev counter has always read just under 10,000 when ticking over. lately it sometimes jumps up to 20,000 or well over 10,000. then if i rev a bit harder, comes back down to normal. anyone know why. thanks tom.
User avatar
Xaccers
Posts: 7654
Joined: 07 Feb 2007, 23:46
Location: Milling around Milton Keynes
My Cars:
x 184

Post by Xaccers »

What car and which engine? :)
1.9TD+ SX Xantia Estate (Cassy) running on 100% veg
1.9TD SX Xantia Hatchback (Jenny) running on 100% veg for sale
Laguna II 2.0dCi Privilege (Monty)

DIY sphere tool
citronut
Posts: 10937
Joined: 29 Apr 2005, 00:46
Location: United Kingdom east sussex
My Cars:
x 92

Post by citronut »

if it,s a petrol engine i would check the idle valve stepper motor

regards malcolm
User avatar
CitroJim
A very naughty boy
Posts: 49532
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6163
Contact:

Re: over revving

Post by CitroJim »

tomrostron wrote:my rev counter has always read just under 10,000 when ticking over.
Sounds like you have a jet engine there Tom with idle speeds like that :lol:

Another cause (on a petrol) can be air leaks at the inlet manifold although Malcolm's thought is the most likely.

If it's a diesel, then it's a whole new ball-game...

As Xac says, we need to know the car and the engine...
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
ACTIVE8
Posts: 2317
Joined: 16 Nov 2004, 16:49
Location: United Kingdom
My Cars:
x 6

Re: over revving

Post by ACTIVE8 »

CitroJim wrote:
tomrostron wrote:my rev counter has always read just under 10,000 when ticking over.
Sounds like you have a jet engine there Tom with idle speeds like that :lol:

Another cause (on a petrol) can be air leaks at the inlet manifold although Malcolm's thought is the most likely.

If it's a diesel, then it's a whole new ball-game...

As Xac says, we need to know the car and the engine...
You should get those extra zero's put in your pay packet! :wink:
ACTIVA

The car that looks like a family car, but has special secret hidden abilities.
tomrostron
Posts: 17
Joined: 13 Nov 2008, 11:22
Location:
My Cars:

Post by tomrostron »

sorry , it is a 99 xantia 2.1td. probably doesnt get up to 20,000 revs. tom
User avatar
CitroJim
A very naughty boy
Posts: 49532
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6163
Contact:

Post by CitroJim »

Thanks Tom :D

That is a different ball-game, especially as it's a 2.1TD with an EPIC pump.

The very first port of call has to be air leaks on the fuel lines and leakoff pipes. Air in the fuel can wreak havoc with the hydraulic servos in an EPIC and in extreme cases, can cause an engine run-away :shock: So, it might well rev to 20,000 rpm under such conditions :lol: :lol:

Look for bubbles in the transulcent parts of the fuel line and check very carefully the leakoffs and fuel return line for leaks. Other old suspects are the filter housing and the primer bulb. Speaking of filters, when was the fuel filter last changed as fuel starvation my cause the problem as well through failing hydraulic pressure in the pump.

Silly question I know, but does it stop more or less immediately the key is turned off? A slight idle increase and a run-on for a split second on cutting the ignition is normal but if it revs and runs on for a few seconds this points to a failing ESOS valve in the pump. These are replacable on a DIY basis but is a 6 or 7 spanner job. The ESOS valve is a funny old thing that takes the role of stop solenoid and throttle and it has small viton tips in it that are known to break up after a long while and fail to regulate speed and stopping. These pumps do not have a conventional stop solenoid or governor; it's all done electronically by pulsing the ESOS valves inside the pump.

I hate to say this as I seem to say it for every problem these days but a Lexia diagnosis is not a bad idea. The Lexia is able to run the EPIC through a full test programme and will reveal any ESOS or timing issues the pump may have.

Despite all the gloom, it's more than likely to be nothing more than an air leak.

For the potential it has to cause a run-away, the problem needs looking into pronto.
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
tomrostron
Posts: 17
Joined: 13 Nov 2008, 11:22
Location:
My Cars:

Post by tomrostron »

thanks jim, where would i get a lexia diagnosis, and what is the cost. thanks again. tom
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Post by DickieG »

tomrostron wrote:thanks jim, where would i get a lexia diagnosis, and what is the cost. thanks again. tom
Either from a Citroën dealer costing something like £60+ or an enthusiast such as Jim or myself, whereabouts are you?
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
tomrostron
Posts: 17
Joined: 13 Nov 2008, 11:22
Location:
My Cars:

Post by tomrostron »

i'm in Bolton lancs. tom
Post Reply