Defender PUMA Anti-Stall Feature in LOW-RANGE - Issues when 4WDriving

[Robmacca]

Guys...

I've only taken my Puma seriously offroad a couple of times and both times I've found when in Low Range that the Anti-stall feature has been more of a hinderance than a benefit... The idling RPM varies up/down oddly as well and it only does this in Low Range. as soon as I move back into the High Range everything returns to Normal in regards to the idling.

Does the Anti-stall feature work in both High and Low Range ??

I've spoken to the fellas at MR Auto and they say its normal behaviour when in Low Range which to me is unfortunate... This Anti-stall feature has caused me some grief in Steep inclines/declines and I'd like to disable it somehow but according to MR Automotive u cannot disable it. The variable idling is another annoying feature that I'd like to rectify as well....

I've also noticed that there is no DASH Indication when u are in Low Range, only for when the CDL is locked... Since this Anti-stall feature cannot be turned off within the ECU, it got me thinking about installing a SWITCH into the HR/LR lever wiring where by I can fool the ECU into thinking that I'm still in High Range so the Variable Idling issues at least don't happen when I'm in Low Range...

What experiences have other PUMA Owners experienced when 4Wdriving in Steep or Rocky Tracks where u really want to go as slow as possible?? Is this a common issue with Pumas or is it just mine?

[Wallaby Ted]

Hi Rob,

I thought it only worked in 1st gear high or low range so putting a switch in wouldn't help. I had the better half driving the defender and she had to go to second to stall it.

No problems going slow in mine except for going down really steep hills as it wants to run away more than the County so need to feather the brakes.

If it surging have you looked at the VCV? Mines was surging until I swapped it.


Richard

[Col 110]

I don't have any noticeable issues with Anti-stall in up hill situations using low 1st - I have been on a few steep hills and don't mind how it crawls up and I just use the gas pedal to help it. Mine doesn't surge......

As Richard pointed out --> down hill in steep conditions I will need to feather breaks as it will want to run away - I wish it handled those situations a bit better - but that could be my inexperience!

Cheers,
Col.

[Robmacca]

Hi Rob,

I thought it only worked in 1st gear high or low range so putting a switch in wouldn't help. I had the better half driving the defender and she had to go to second to stall it.

No problems going slow in mine except for going down really steep hills as it wants to run away more than the County so need to feather the brakes.

If it surging have you looked at the VCV? Mines was surging until I swapped it.


Richard

Yes, in regards to the Anti-stall it works in 1st gear I believe whether HR or LR... but the fluctuating rev issue I'm experiencing only happens in Low Range - as soon as I change into High Range, the issue disappears. I did have the VCV replaced not long after buying the car back in 2018 and I've only put about 20k on the vehicle to date...

When in 1st gear LR, I don't like how the anti-stall fights against u when u want to apply the brake to slow u down w/o putting your foot on the clutch as well. This is especially nervous when trying to reverse down a steep rocky track and u don't want to use the clutch but u also want to slow yourself down as the same time... I found that I couldn't do this and I had to use the clutch otherwise the anti-stall would increase the engine revs and thus the speed.... not good in my opinion...

It looks like the fluctuating revs when in LR might be a separate issue then if no one else is experiencing it ??

[Robmacca]

I don't have any noticeable issues with Anti-stall in up hill situations using low 1st - I have been on a few steep hills and don't mind how it crawls up and I just use the gas pedal to help it. Mine doesn't surge......

As Richard pointed out --> down hill in steep conditions I will need to feather breaks as it will want to run away - I wish it handled those situations a bit better - but that could be my inexperience!

Cheers,
Col.

Going up is not a problem... but if u had to reverse back down, that is when it becomes a problem... u end up going quicker than u would like and u are forced to use the clutch otherwise the Anti-stall will fight against u applying the brakes and will want to increase the revs and therefore the speed which is not good when reversing down steep/rocky hills...

[filcar]

I've never has any problem with the anti stall, in fact it works brilliantly. Anti stall works in all forward gears high and low but really only up to 3rd in high and of course in reverse as well. Been up many steep rocky hills with poor traction in 2nd low just using anti stall alone. As soon as you touch the throttle you lose anti stall so if you don't like what anti stall is doing, use the right foot. I have always found reverse and 1st in low range plenty slow enough to handle any hill, if nervous dab the brakes to lose a bit of speed, don't try and ride them, and you won't be fighting the anti stall.

The only idle issue I have noticed with the Pumas is increased idle revs in 1st and reverse low, when you push in the clutch the revs will remain slightly higher for a few seconds. My understanding of the increased revs in those gears is because they are so low the engine braking can be more than traction.

Like I said I have done a good amount of 4x4 in my 90 and love the anti stall and the slowness of the low gears, can't imagine any slope with reasonable traction where low 1st (or reverse) and occasional dabs on the brakes if needed wouldn't be slow enough to maintain full control.

[ashtrans]

Guys...

I've only taken my Puma seriously offroad a couple of times and both times I've found when in Low Range that the Anti-stall feature has been more of a hinderance than a benefit... The idling RPM varies up/down oddly as well and it only does this in Low Range. as soon as I move back into the High Range everything returns to Normal in regards to the idling.

Does the Anti-stall feature work in both High and Low Range ??

I've spoken to the fellas at MR Auto and they say its normal behaviour when in Low Range which to me is unfortunate... This Anti-stall feature has caused me some grief in Steep inclines/declines and I'd like to disable it somehow but according to MR Automotive u cannot disable it. The variable idling is another annoying feature that I'd like to rectify as well....

I've also noticed that there is no DASH Indication when u are in Low Range, only for when the CDL is locked... Since this Anti-stall feature cannot be turned off within the ECU, it got me thinking about installing a SWITCH into the HR/LR lever wiring where by I can fool the ECU into thinking that I'm still in High Range so the Variable Idling issues at least don't happen when I'm in Low Range...

What experiences have other PUMA Owners experienced when 4Wdriving in Steep or Rocky Tracks where u really want to go as slow as possible?? Is this a common issue with Pumas or is it just mine?

there is a switch at the top of the front housing on the Transfer case, above the front prop shaft flange,

if you unplug it, it won't know you are in low,

[Robmacca]

there is a switch at the top of the front housing on the Transfer case, above the front prop shaft flange,

if you unplug it, it won't know you are in low,

Thanks for that... that might just solve the issue....

I was mucking around with it yesterday down the paddock and what I found was that when I was in LR and in neutral gear and I just coasted down the hill that the revs would vary as I put my foot on/off the brakes.... I found this quite weird... It didn’t do it in HR

[filcar]

Thanks for that... that might just solve the issue....

I was mucking around with it yesterday down the paddock and what I found was that when I was in LR and in neutral gear and I just coasted down the hill that the revs would vary as I put my foot on/off the brakes.... I found this quite weird... It didn’t do it in HR

This is just the ECU trying to match engine revs with ground speed

[Tote]

I read somewhere when I got my Puma that the increase in revs is a largely physiological thing and the extra couple of hundred RPM is a very small increase in speed when the reduction ratio in low 1st or 2nd is considered. Armed with this knowledge I trained myself to not be concerned with the rev increase.

Regards,
Tote

[karlz]

I read somewhere when I got my Puma that the increase in revs is a largely physiological thing and the extra couple of hundred RPM is a very small increase in speed when the reduction ratio in low 1st or 2nd is considered. Armed with this knowledge I trained myself to not be concerned with the rev increase.

Regards,
Tote

I concur.

I have had no issues with it, even in extreme downhill descents.
Its more of a benefit than a hinderance.

[DiscoMick]

Takes it to about 900 revs on mine. Never found it a problem.

[Tote]

Welcome back Mick.......

Regards,
Tote

[POD]

I have found a couple of times when crawling in low range and the engine starts to labour a bit on the anti-stall, I had the tendency to touch the throttle a tiny bit which would result in a stall; just enough throttle to switch off the anti-stall but not enough to power through the situation. If it's hanging on by the anti-stall and you want a little more power, it can require a bit more right foot than you think. The anti-stall definitely works in all gears but obviously is not magic and will not provide enough torque where too high a gear is selected.

[Robmacca]

I have found a couple of times when crawling in low range and the engine starts to labour a bit on the anti-stall, I had the tendency to touch the throttle a tiny bit which would result in a stall; just enough throttle to switch off the anti-stall but not enough to power through the situation. If it's hanging on by the anti-stall and you want a little more power, it can require a bit more right foot than you think. The anti-stall definitely works in all gears but obviously is not magic and will not provide enough torque where too high a gear is selected.

Going forward is not the issue that worries me, its when u are attempting to get up a steep rocky incline offroad and u don't make it and u have to reverse back down as slowly as u can. This is when I reckon the LR issue I mentioned is a safety concern. In Low Range & reversing back down hill and trying to go as slow as possible but then the anti-stall fights against u, thus increasing the revs and speed - The only way to combat this is by using the clutch more than u really should when reversing back down the steep rocky hill. Not good IMHO...

I've reversed down many steep hills before in other 4wd's without any issues but these 4wd's also never had anti-stall either. I just found this anti-stall feature to be more of a hinderance when reversing, not a problem when going forward...