The Lotus Grand Tourers

Car was in for some paintwork and for some reason they disconnected the battery..Now the cruise control is not engaging. Is there something needs reset? Appreciate any help.

Where were they painting? Battery should not make any difference.

Mine is on a quick disconnect and it's on and off loads. It is mainly earths; brake switch (how are your brake lights?) and the speedo pick off.

They were painting bonnet, no reason to disconnect battery. Brake lights working, will have to check speedo switch. Seems strange as was working perfectly before coach work visit.

My 1987/88 SA developed a serious clicking noise near the intake manifold, which sounded like there was a serious issue near the top of the engine. The ticking sound only occurred when the transmission was in DRIVE. The noise ceased when either the brakes were applied or the car built up speed, but would return when slowing down.

I assumed it was the brake servo non-return valve. Steve at SJ agreed and he supplied me with a replacement brake servo non-return valve. It was a ten minute install.

Unfortunately this was not the problem. With the help of my son-in-law standing at the passenger side of the engine bay he could clearly hear, see and feel the knocking noise inside the cruise control actuator. We first removed the fuse (no 4 - which also controls the stop lights) and the noise subsided. I then removed the back panel of the glove box and disconnected the actuator plug coming through the firewall to the CC ECU behind the glovebox, completely removing (I believe) all electrical power to the actuator.

I just completed a test run down the M1 and all seemed well until one moment when the noise returned for a short period...once again to dissipate when I applied the brakes!

Any ideas what may be happening? Does anybody know:

1) Who is the manufacturer of the cruise control actuator?

2) Does the actuator have both electrical and mechanical mechanisms?

3) Can the actuator be rebuilt?

4) Has anybody had similar issues.

Most of you know that the SA is a very rare breed. I understand that less than 40 were ultimately produced.

fairline38 wrote: ↑

Sun Mar 21, 2021 13:13

Does anybody know:

1) Who is the manufacturer of the cruise control actuator?

2) Does the actuator have both electrical and mechanical mechanisms?

3) Can the actuator be rebuilt?

4) Has anybody had similar issues.

Most of you know that the SA is a very rare breed. I understand that less than 40 were ultimately produced.

The actuator and control module are VDO used on BMW of the era.

Disconnect the module behind glove box rhs approx

I do find the cruise control useful on long motorway journeys (so long as traffic is not too heavy). However, I do find it a bit jerky i.e. I can feel, through the seat and steering wheel, the power constantly cycling on and off in order to maintain the required speed. I am sure I haven't noticed this in other cars I have used with cruise control. Do other SA users find this? Could it be a faulty actuator?

The actuator will be constantly pulsing as it pulls the throttle and then relaxing as it hits speed setting. As the car slows as soon as the 'throttle' is relaxed the system will request another throttle pull to get back up to speed - just like your right foot does on the pedal. I assume it to be normal for a cable driven system.

lambert.john wrote: ↑

Sun May 22, 2022 23:24

I do find the cruise control useful on long motorway journeys (so long as traffic is not too heavy). However, I do find it a bit jerky i.e. I can feel, through the seat and steering wheel, the power constantly cycling on and off in order to maintain the required speed. I am sure I haven't noticed this in other cars I have used with cruise control. Do other SA users find this? Could it be a faulty actuator?

I'd look into the system and try to find if there is any adjustment possible for the sensitivity, ie when it starts to correct for deviation of the set speed, and how much throttle it gives to get back on track