Accelerator Cable

[Guest peterd]

Hi Guys,

 

Modeo Diesel.

 

I've been on holiday towing a caravan, sorry!

 

It was OK running up to Edinburgh but driving around in the days afterwards the car was getting slower and slower pulling away from lights, etc.

 

I thought I'd blown the Turbo...

 

It was OK once I got up to speed, 60 - 70mph, no problem.

 

I considered everything and thought that I should check the fuel filter for water, all OK. Then I noticed a rattle sound as I pulled away, like a petrol engine running weak. Had another think and couldn't rememer when I'd last changed the fuel filter so I got one and bunged it on.

 

Problem sorted. I changed the air filter too, just to do a decent job.

 

Ok for one day, then it started to get slower and slower again. At one point I was at the lights, head of the queue. Lights went to green, I put my foot on the floor and the car stayed at 1000rpm for about five seconds before creeping up slowly and I had to ride the clutch to get moving.

 

So I got the wife to work the pedal while I looked under the bonnet to find which cable it was on the injector pump...

 

and the cable was bouncing around all over the place as she applied pressure. There's this daft telescopic spring-loaded gadget half way down the cable that was taking up all of the slack in the cable and the throttle lever at the pump was only moving about a quarter of an inch.

 

When I flicked it by hand it revved as normal.

 

What is this thing?

 

I noticed a groove around the bit that slides in, like it should have a clip on it to stop it sliding. So we had Irish Stew for tea out of a tin, and I took the lid, cut a slot in it with my Swiss Army knife and plopped it in place in the slot.

 

The cable now works as it should and I got the car and caravan home OK.

 

Looking at engines in the local scrap yard for a proper 'clip', none of the cars have one fitted. I can easily modify a washer to do a more permanemt job, but would it have any detrimental affect on the engine or performance?

 

Why does this thing telescope in? What's it supposed to acheive? Could it be that the pump lever is sticky and it takes more pressure to operate that it should do making the cable spring collapse?

 

Any ideas welcome.

 

Regards

Peter

[Guest fredt]

Do you have traction control? if so IIRC this bit of kit is used to dampen the throttle action by the traction control system, it simply lengthens the throttle cable when the system detects the loss of traction allowing the throttle to close slightly despite you having you foot to the floor!

[Guest neil_wiles]

The plastic tube and spring you are refering to is an accumulator and is designed to reduce the speed of the throttle body operation, both on acceleration and deceleration. The lack of movement of the throttle body is normally due to heat distortion in the body of the accumulator.

 

The norm for this item is for it to delay the rapid input to the pump and allow the pump to open at a controlled rate and the same when the pedal is released the pump speed reduces at the controlled rate reducing the "kangaroo" effect of rapidly opening and closing the pump rate. This improves driveablity but if the body is distorted can cause reduced throttle body actuation or increased idle speed during drive cycles. (sticky throttle ).

 

Hope this helps

[Guest peterd]

Hi,

 

Thanks fo the info.

 

As far as I know the car doesn't have traction control, it's a basic model from 1994.

 

I'd half-guessed that this thing was to control the throttle opening. As it's not sticking, it's moving too freely, I was thinking of changing the spring but I can't see any way of doing that. I'll probably end up with a new cable (depending how tricky it is to get the cable attached to the pedal!).

 

Meanwhile, the bit of tin is still in place and working well for over a week now on runs to the coast on Sunday as well as around town.

 

Regards

Peter