Cruise Control

[A80Avant]

i have been having a different problem with the cruise control

seems that the pump cannot keep the vaccum hard enough sometimes, and other times it works fine.

i have changed the pump already once, and the hoses as well. Im now thinking of using nylon tubing instead, just to eliminate the possibility of a collapse. As my cruise control is modified and has a bit more work to move the throttle plate, im wondering if that is why the pump is finding it hard. But that wouldnt explain why it sometimes works and others dont...

[veneto rs2]

i have been having a different problem with the cruise control

seems that the pump cannot keep the vaccum hard enough sometimes, and other times it works fine.

i have changed the pump already once, and the hoses as well. Im now thinking of using nylon tubing instead, just to eliminate the possibility of a collapse. As my cruise control is modified and has a bit more work to move the throttle plate, im wondering if that is why the pump is finding it hard. But that wouldnt explain why it sometimes works and others dont...

I had a random lost of vacuum on the pipes of the Cabrio myself and I found that the problem was on one of the pedals switches.
Not that it was faulty or broken but simply needed to be set properly in close position.

Stefano

[A80Avant]

i will check that as well, thanks!

[veneto rs2]

i will check that as well, thanks!

Best way I found to check them it's by disconnecting the related hose from inside the engine bay join a longer hose long enough to reach the footwell and blow gently but constantly with a mechanic siringe on the hose and listen for leaks.

Stefano

[A80Avant]

you mean that way to listen for leaks from any vaccum hoses? I have recently replaced all those original hoses with a silicone one. I just modified the brake sensor slightly so that its permanently shut as there was a bit of slack.

now its down to the pump or controller if it still doesnt work.

having said that, the stalk from day one only very occasionally had the resume function working, so im probably going to give the connectors a bit of a clean as well.

[A80Avant]

Im afraid the change i made isnt good enough for the clutch actuator. I need to get a nut to secure the actuator better and also allow for the clutch to fully disengage.

Does anyone remember the diameter of th actuator as im about to drive to halfords

Edit: i just got a whole set of nuts and bolts which i needed so i should have the correct one now in.... which none of those worked as the sensors are this idiotic 11mm instead of 10 or 12.

so i ordered the original clips that fit in there and hopefully that will do the trick

[prj]

Did you already re-flow all the joints in the cruise controller?

Pretty common fault with those that the joints crack and give all sorts of intermittent issues.

[A80Avant]

if you mean the T pieces of the system, yes those i checked when i replaced all the vaccum lines. They were ok. What i may do in addition is use tyreups on all connections just to eliminate the possibility of loss of suction

[mcandmar]

I've had the most trouble with the switches on my cars, but its easy to disassemble it and clean all the contacts. As you said the resume function never worked on my S2 until i took the switch apart and cleaned it.

As Prj says, re soldering everything inside the controller is worth doing too, fixed the issue with our S4 in that the CC only worked when the inside of the car was warm.

[prj]

if you mean the T pieces of the system, yes those i checked when i replaced all the vaccum lines. They were ok. What i may do in addition is use tyreups on all connections just to eliminate the possibility of loss of suction

If you were talking to me, then "joints" is referred to "solder joints" in electronics and re-flowing means re-soldering them.
I was talking about the board inside the controller, often the solder will crack and you will get intermittent connections which can be affected by heat and vibration so the unit randomly works and then doesn't.

If you can't find any logic as to why your cruise control randomly stops working that's the first thing to check on these, seen plenty of them go south that way...
Lead-free solder is to blame.

[A80Avant]

aha i see.
another small gadget for me to buy then..

any particular type of soldering equipment you would suggest?

[prj]

aha i see.
another small gadget for me to buy then..

any particular type of soldering equipment you would suggest?

I'd say get it done somewhere.
If you want to do it yourself, a 30 watt soldering iron is good, but can have issues melting through the lacquer.
The problem with higher powered soldering irons is that they will heat up too much.

The optimal solution is a temperature controlled soldering stations (which is what everyone uses who does this more often), so you can have high power, but controlled temperature.
This job is also doable with a hot air station.

The latter two are a complete overkill for this job though. Get the 30w iron for a few quid and some thin solder, maybe some solder wick. These are the basics that will get you going.
Also, watch this video, it will explain how everything works: http://www.youtube.com/watch?v=I_NU2ruzyc4

[A80Avant]

thanks

edit:
just checked my spare controller and it looks immaculate. All soldering areas are as good as new. Nothing falling off.

[Acidburn]

Also, watch this video, it will explain how everything works: http://www.youtube.com/watch?v=I_NU2ruzyc4

Nice video, been a while since I had to do any major soldering but I will be doing some soon with the loom for my white car so a good few tips and reminders.

[John B]

Hi John.
Sorry for the slow reply.
I've just been trying to remember exactly where I connected all these wires...

1) I think i connected this next to the brake light switch. But this should be easily testable with a multimeter.
2) I made no connections to the rev counter signal at all... This might be your problem... black/blue wire is a 12v power supply - fused side of S12. I can't remember where I found this, but I think it this is the power supply to the instrument cluster?
3) white/blue is the vehicle speed signal, and I think I found it on it's way into the centre console, because it goes to the DIFFLOCK switch. But behind the instrument cluster is a perfectly good place to get it.

Hopefully that's useful.
If you need anything else I can go and dig around to find out exactly where i connected to.

JB

Hi JB

Still having issues with my cruise installation even though i've now disconnected the wires i had previously connected. I seem to have lost half the instruments on the dashboard but i think this is actually a disturbed connection probably because i eased the fusebox out of its housing to have a peek underneath.

When i put my lights on, the full beam indicator and light turn indicator light come on (as well as the speedo not working!). Even reverting back to the original (non-cruise) indicator, this still happens!

As regards your locations: -

1) Yes i have done this
2) I have connected this incorrectly in the past: It would be helpful to know whwre you hooked this into i.e. where the wire from S12 goes to physically when it leaves the underside of the fuse box
3) When i look at the diagram (ABY - MY94 - diagram 31/1) for the diff lock there is no blue / white wire only a brown / white and a brown wire to the diff lock switch. However on Paul's wiring and schematics PowerPoint presentation, the white / blue VSS wire can be seen on pin 9 of T10, which fits into the Front Auxiliary Panel. It would be helpful to know where you hooked this into though.

Cheers

JB