My power steering is stiff....

I own a non-turbo Supra which has been meticulously maintained, though there is a problem with the power steering, that is really starting to annoy me.

Firstly the power steering is working (I know what it feels like when the power steering goes completely!!! Not nice...) but it feels slightly stiff for most of the time.

For most people, it would probably be bearable, but I sustained a shoulder injury in a car accident a few years ago and iut can get really painful.

I have had the vehicle for about 5 months, and only about 3 weeks ago for a 3 or 4 day period the steering loosened up and felt amazing but now its gone back to moderately stiff again. It doesn't seem too bad if I've been driving for a while, particularly at speed, though still doesn't lossen up 100%.

I have also found that it loosens up if I'm moving sowly on ie. a very gravelled area but as soon as I start driving properly it goes bak to moderate stiffness.

I had the car serviced at Fish Brothers Toyota in Swindon last week and they recommended a PAS pump. As I didn't want to waste this much money without really knowing, I obtained a pump (from a car that had done 60,000 in comparison to my 85,000 miles) but upon having this fitted, the steering feels exactly the same.

Has anyone encountered a similar problem?

I previously had a Nissan 300zx which had a similar problem, though for the most part the power steering was gone completely. People on the zx forum suggested the speed sensor amongst other things. I sold the car without ever finding out what the problem was, but I don't want to do that with this car, as everything else is fine.

Does the Supra have a speed sensor, and if so could it be this?

I would appreciate any advice on this matter. Also does anyone know of any Supra mechanic specialists within travelling distance of Bristol?

Many thanks

[timwildman]

Some people in the past have had a problem with a poor speedo conversion. The steering is speed sensative. If the conversion isn't right it'll affect the steering and active spolier operation.

[Martin F]

Hi and welcome.

It could be an iffy speedo conversion. There are a lot of systems in the Supra that rely on the speed signal and the progressive power steering is one of these.

In theory the power steering should give greatest assistance up to a set speed (say 30mph) and then after that only give a little assistance to steering actions. It does this by switching in and out a solenoid on the side of the power steering rack.

This solenoid receives its signal from a seperate power steering ECU which uses the cars speed signal to determine when to switch the solenoid in or out.

If your power steering ECU is receiving a scaled output from your kmh to mph converter then the level of power steering assistance will be reduced sooner than it should be.

For some more info take a look at this link

http://www.thor-racing.co.uk/TRL/dsc_mkiv.html