Tickover and rack

[Petrolhead]

Hi

 

Had a great blat out today but notices a couple of thing when I got home.

 

1. The tickover is at 2000 rpm which is a bit high I think. I tried the suggestion on a previous thread 'Ignition on, press throttle 5 times' but no better.

 

2. I have noticed a small amount of play in the rack, side to side, and was woundering if there a way to adjust this play out.

 

Any ideas?

 

Peter

 

Better to go in a blaze of glory than to fade away teeth.gif

[Roger King]

Peter,

 

What engine have you got? If it is a carburettored car of some sort, the throttle cables are notorious for becoming sticky and causing your problem - even if the adjustment is theoretically correct.

 

The easiest way to prove or eliminate this is to disconnect the cable at the carburettor end. You will have to operate the carb linkage by hand to start the car, but if the tickover returns to normal the cable is almost certainly the problem. Solutions are new cable, rerouting of cable, lubrication of cable, or possibly all three.

 

If this does not cure the fault you will have a carburettor problem and should get it seen to before using the car again. There is a big saftey issue with this sort of fault - throttle jamming open etc - no fun on track and potentially much worse on the road.

[CHRIS CLARK]

PTHead.

 

I assume it's a 'K' ? Sounds as if you may have a throttle pot sticking. You could unplug the Mems ECU then re-connect, ignition on, and push acelerator pedal slowly to full travel six times (maybe it is five?). Throttle cable isn't jamming/too tight is it ? Easy to adjust the free play to suit!

 

Steering rack; just had mine in bits (std 8%). There are a pair of caged ball races supporting the input shaft (at either end) which in turn bears onto the rack itself. There is a nylon pressure plate which is sprung loaded to control 'slop'. This is the only form of 'adjustment' and the spring pressure is controlled by the cover plate and shims. I don't think this really is an item for 'playing' with other than to re-grease at long intervals.

Could it be play in the swivel joints on the wishbones ?

[PACR]

Check it's not the air filter distorting the throttle bodie - on a K-series - if the jubilee clips a turn too tight it gives a 2000 rpm idle....

 

I was thinking of using a bit of glue to hold it in place (along with the clip) - but don't want bits of it to get sucked into the engine. Anyone solved this problem?

 

Piers

[Petrolhead]

Darn and confound. If only I had a brain. Sorry guys

 

Its a 1.4 SS K series.

 

The throttle cable is fine, the airfilter is not overtightened, I'e tried the 'press the padal 5 times'.

The stop on the throttle body, how should this be set?

 

I havn't tried disconnecting the ECU but will. Is this an OK thing to do?

 

The rack slop is noticable when the wheels are in the straight ahead position and I gently turn the Sterring wheel left and right about centre. I would say the free play is about 10 degrees on the steering wheel. I have checked closely and it dosn't seem to be play in the swivel joints on the wishbones or track rod ends.

 

Peter

 

Edited by - petrolhead on 21 May 2001 09:19:26

[Tony]

Regarding your steering 'slop'. Once, on the St. Moritz trip, mine started to develop a little play around the straight ahead position. Got gradually worse. Turned out to be loose connection between the main steering column and the short one which goes through the dash. Have a look at the connector by the brake reservoir. Just a thought.

[Mcalvert]

I had the same problem which I cured with the following information posted on the Sevens list:

 

Where the column enters the rack, at 90 degrees to the column there is a big

adjuster secured with a lock nut. BEFORE YOU DO ANYTHING ELSE, mark the

current position of the adjuster (to the lock ring and to the rack body)

using tip-ex or some such substance. You can then loosen the lock nut (big

adjustable spanner) and adjust the mesh of the rack and pinion (Allen key).

Because tightening the lock ring changes the meshing slightly, you have to

move the adjustment by small amounts tighten it up and test with each

adjustment. You shouldn't test for slack, but for the onset of *noticeable*

friction. Mine needed adjustment of about 3mm at the circumference of the

adjuster (hence the tip-ex mark). The tip-ex also means that you can remove

the adjuster entirely to have a look at what it does inside the rack and get

it back to approximately the right place to start the fine adjustment.

 

Testing needs as little mass as possible to be attached to the system. You

can do this by knocking the rod ends out of both steering arms and taking

your wheel off. It would be better if you didn't have te column attached,

but it is not entirely necessary as it has a low moment of inertia. You can

do all of this with the rack in the car.

 

Testing involves moving the rack through its range of movement by pushing

and pulling on one track rod. The friction in the system is much more

apparent here than at the steering wheel. You should ignore resistance at

the very ends of the rack travel as the compression of the boots starts

having an effect, with air wheezing in and out. The majority of the travel

should be free running. Adjust until you feel the friction and then back

off by the width of a gnat's tadger.

 

[V7 SLR]

A small aside to this... I've spent ages trying to find a spanner big enough to undo the rack's lock nut, but have failed. I've even bought 3 bloody adjustables, each bigger than the previous one, with no luck. So I did what I should have done originally, and measured the damn thing. It's 36mm across the flats, and Halfords market a Sykes Pickavant spanner which is intended to undo-do up Viscous Fan Hubs (whatever they are) which are.... da daaaaa 36mm.

 

I've only just bought it. Hope the bloody thing fits. wink.gif

[Simos]

I'd second Tony's comment, on several occasions, sudden slop around the straight ahead position has been resloved as play in the joint linking the two halves of the steering column. for 10o you can probably see it by removing the bonnet and wiggling the wheel. If so, slacken the big 17mm? locknut and tighten the 6mm? hex bolt whilst jiggling the steering then re-tighten lock nut.

 

Simon.

 

Edited by - simos on 21 May 2001 15:18:02

[Petrolhead]

Cheers for all the advice re the rack.

 

Any more info regarding tickover. It seems to be a common problem.

 

Peter

 

Better to go in a blaze of glory than to fade away teeth.gif

[Peter Carmichael]

I would amend Simos' advice slightly...

 

Instructions on a safety related mod here

There is an important safety related mod to make to the Caterham

collapsible steering column assembly.

 

***** File the end of the grub screw in the steering column clamp flat.

*****

 

It now won't dig into the flat surface on the lower steering column, and

in an impact the column halves will slide as intended.

 

Also, you won't have to tighten the grub screw so severely to take out

the slight give in the steering.

---

 

... if you just keep tightening the grub screw you will bend the clamp and the problem will come back shortly afterwards. Get your file out...

 

As for rack adjustment, I would urge the strongest caution. Better to have a bit of play than a bit of friction.

 

Edited by - peter Carmichael on 21 May 2001 16:36:00

[stevefoster]

The big nut is 36mm. The hex key is 7/32". Nice mix of metric and imperial huh!

Ford water pump nut spanner is a good source.

 

I bought a 36mm socket with a hex spanner neck and use that with the hex key in the middle hole...

/Steve

[V7 SLR]

Hurraaaah. It fits. Adjustments here I come.