Low performance Help - Page 2

viv cockburn · 7th March 2008, 13:49

Thanks for all your help and the info, will let hubby know when he gets home from work tonight. Keep you posted how it goes.

Viv

Departed · 7th March 2008, 19:29

If you add your location, there might be someone nearby who can test them for you. The testbooks have an option to drive the motors so you can hear if they operate.

soixante-quinze · 31st March 2009, 13:50

After having read your post, and being unemployed at the moment, I eventually decided to tackle my car's VIS issue this morning. Basically, ever since buying the car it's had a sort of stutter at about 1800 rpm, seems to have a tappety noise coming from manifold and has been seriously lacking in low-end torque. This last issue manifesting itself in not being able to pull away in anything other than 1st gear without the risk of stalling.

I refreshed my memory regarding stripping the motor casings by reading some threads on here and then set to business.

I did the front one first. It came apart quite easily, but I didn't quite follow the 'Sheddist' methodology exactly. When I had the assembly slightly open, I used my blade to prise the worm gear from its clip/bushing, thereby keeping the pcb attached to the 'base' rather than the 'lid'. Anyway, to my surprise there was very little oil in the assembly (contrary to experience of most) and there was nothing wrong with any soldering, nor anything else. After a cleanup I reassembled, which, as a matter of interest requires one to use a vice-grip to clamp the assembly 'shut' as one engages the worm gear in its clip/bushing.

The rear one next. Followed the same opening methodology again, but this time on opening, found there to be much more oil in situ. Otherwise though, nothing wrong again. Did a clean-up, and proceeded to lose the little thrust washer from the worm gear

Anyway, when reassembling, I realised that I needed to assemble the pinion gear in the right position so that it would later mate up with the shaft of the VIS butterfly in the manifold. I had to do this before clamping the assembly closed, because I was unable to turn the pinion from the outside once reassembled (I put this down to the high gearing between worm and pinion). Anyway, in trying to decide exactly how to do it, I noticed that there is a little arrow moulded on the pinion that needs to match up with an arc of a quarter circle moulded onto the outer casing of the housing. I suspect that these markings help one to ensure that the right things are happening inside the assembly as one clamps it shut, and that if this is not done, the VIS will not work. The reason I surmise this is that the symptoms my car used to display are now gone, and yet, I never found any of the typical faults found by others, so didn't really fix anything as far as I'm concerned. All I can think is that the VIS motor assembly was faulty wrt this 'matching' issue when the car was put together by MGR.

Maybe one of the more experienced VIS motor 'specialists' might have another point of view, but, hey, I'm a happy bunny now anyway

7th March 2008, 13:49	#11
viv cockburn Newbie rover 72 club Join Date: Mar 2008 Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts	Low performance Thanks for all your help and the info, will let hubby know when he gets home from work tonight. Keep you posted how it goes. Viv

7th March 2008, 19:29	#12
Departed Retired -- Join Date: Jan 2007 Location: -- Posts: 3,785 Thanks: 0 Thanked 4 Times in 4 Posts	If you add your location, there might be someone nearby who can test them for you. The testbooks have an option to drive the motors so you can hear if they operate.

31st March 2009, 13:50	#13
soixante-quinze Avid contributor Rover 75 Saloon Join Date: Nov 2006 Location: Kilcock Posts: 141 Thanks: 0 Thanked 2 Times in 1 Post	After having read your post, and being unemployed at the moment, I eventually decided to tackle my car's VIS issue this morning. Basically, ever since buying the car it's had a sort of stutter at about 1800 rpm, seems to have a tappety noise coming from manifold and has been seriously lacking in low-end torque. This last issue manifesting itself in not being able to pull away in anything other than 1st gear without the risk of stalling. I refreshed my memory regarding stripping the motor casings by reading some threads on here and then set to business. I did the front one first. It came apart quite easily, but I didn't quite follow the 'Sheddist' methodology exactly. When I had the assembly slightly open, I used my blade to prise the worm gear from its clip/bushing, thereby keeping the pcb attached to the 'base' rather than the 'lid'. Anyway, to my surprise there was very little oil in the assembly (contrary to experience of most) and there was nothing wrong with any soldering, nor anything else. After a cleanup I reassembled, which, as a matter of interest requires one to use a vice-grip to clamp the assembly 'shut' as one engages the worm gear in its clip/bushing. The rear one next. Followed the same opening methodology again, but this time on opening, found there to be much more oil in situ. Otherwise though, nothing wrong again. Did a clean-up, and proceeded to lose the little thrust washer from the worm gear Anyway, when reassembling, I realised that I needed to assemble the pinion gear in the right position so that it would later mate up with the shaft of the VIS butterfly in the manifold. I had to do this before clamping the assembly closed, because I was unable to turn the pinion from the outside once reassembled (I put this down to the high gearing between worm and pinion). Anyway, in trying to decide exactly how to do it, I noticed that there is a little arrow moulded on the pinion that needs to match up with an arc of a quarter circle moulded onto the outer casing of the housing. I suspect that these markings help one to ensure that the right things are happening inside the assembly as one clamps it shut, and that if this is not done, the VIS will not work. The reason I surmise this is that the symptoms my car used to display are now gone, and yet, I never found any of the typical faults found by others, so didn't really fix anything as far as I'm concerned. All I can think is that the VIS motor assembly was faulty wrt this 'matching' issue when the car was put together by MGR. Maybe one of the more experienced VIS motor 'specialists' might have another point of view, but, hey, I'm a happy bunny now anyway