Hi

 

Just started the car first time since before Christmas to move it and although it started ok it idled as though the throttle was being blipped repeatedly - like a boy racer at the lights sort of thing.

 

It settled after a minute or so but after moving it and letting it run for a while I revved it again and held it at a fast idle for a few seconds and on returning to idle the pulse was back again but less so, settling down to an even idle after only a few seconds this time.

 

Something to look out for or likely to settle down once it's in use again?

 

It's a 1.9 diesel. Battery has been connected the whole time it's been unused and that's been 10 days.

 

It's a pretty specific symptom so hope someone can point me in the right direction.

 

Thanks

 

Mitch

Hello,

My diesel does the same sometimes, it's normally after hard acceleration my throttle sticks, I find if I lift the clutch slightly in gear with the brakes on it drops the revs back done to normal, be an interesting read if anyone else has this problem

I don't know, it's not that the revs were high, the idle was just up and down - as I say, just like someone blipping the throttle repeatedly.

Moisture in the fuel, or air in the fuel lines.

I'll have to see what comes out of the bottom of the filter. Been taking advantage of that Tesco offer lately so not filled up at the usual place for 2 of the last 3 tanks. Could be condensation at this time of year though. Who knows...?

 

With what you said about the hesitant acceleration an air leak still sounds likely. Economy has been about the same as for this time last year though, maybe even better so don't seem to be losing fuel.

Or maybe the idle boost actuator is not working properly, maybe dodgy electrical connection at the solenoid or a leaking vacuum line to or from it.

I pulled and checked a few visible electrical connectors but which are they, where are they specifically? One of the two little black units to the right of the engine looking from the front of the car?

 

None made much difference to the hesitancy. Dificult to say about the idle pulsing though 'till tomorrow morning.

Yes, the idle boost actuator solenoid is to the right of the engine, can't rememebr which is which now, but the other is the egr valve solenoid,

the way the idle boost system works is by a secondary lever acting upon the main throttle lever, it sits underneath the main throttle cable and the vacuum operated capsule pulls the main lever off the idle stop during the warm up phase..

I would run th engine up and observe the idle boost lever operation to see if it's causing the blipping you mention.

Thanks, I'll do that. I'll re-check the connectors and I think I'll get some of the hose ordered too.

Well I checked the vacuum hose and it looks fine. Then I pulled the connector and that looks fine too so I put it back. Started the car and it was also fine which is good but at the same time I'd have liked to see if the idle boost was moving now that I know where it is.

 

The idle speed boost valve is the one on the right here (light grey connector):

 

(The one to its left is the EGR solenoid.)

 

The idle speed boost actuator that I may have been able to see moving is this:

 

You can see the vacuum hose connection from the solenoid - the braded hose on the right. It's only the two ends that look like this, the main hose is a much narrower plastic tube.

 

For more context, this is the injection pump with the actuator bottom right. It connects via cable to the boost lever on the left (partly hidden behind the fuel return hose):

Edited 30 December, 201411 yr by Red Studio

Thanks for that red, that is a really good post above.