3200 Engine racing in Neutral & Park

MeltonBrand

New Member
Messages
6
Evening All. Odd problem cropped up today.

3200 has been running beautifully for the few weeks I've had it. Today when I left a meeting the CEL illuminated and the car limped to the next parking lay by.

I reset the throttle upper and lower. Started up, no CEL, but the engine started racing in Park (up to 4,000) and even in drive would idle at 1500 rather than the usual 1000 ish.

Got home. Reset the throttle again and the problem is gone. Any thoughts?
 

Zep

Moderator
Messages
4,380
The most helpful set of responses ever, and Benny hasn’t even arrived yet. :D

I seem to recall there being issues with magnets breaking up in the throttle body which can cause it to stick, but @davy83 is probably best placed to comment.
 

StuartW

Centenary Club
Messages
8,609
The other end of the DBW could be playing up too, I had issues with my pedal sensor which included random revving so that may need to checking also
 

Rex B

Member
Messages
594
Hi
Classic symptoms of throttle body problems. Do you know if it’s still original or if it’s has been converted to contactor less.?
Rex B
 

Markc

Junior Member
Messages
79
The most helpful set of responses ever, and Benny hasn’t even arrived yet. :D

I seem to recall there being issues with magnets breaking up in the throttle body which can cause it to stick, but @davy83 is probably best placed to comment.
One has to have a sense of humour with a 3200! Spoken from experience.
 
Reactions: Zep

davy83

Member
Messages
2,315
although your pedal recalibration seems to have fixed it, i am suspicious that its really the throttle body that's causing the problem. the engine revving high is more often down to the TB sticking or the rotary sensors failing. Sadly the rotary sensors in the pedal pot also fail and can cause mayhem too (unless the pedal sensor is one of mine, in which case this should never happen)
The magnets in the TB assembly start to come apart and this forms a furry sort of layer of bits of magnet around it and this eventually starts to cause friction between the motor and the windings and since it uses the motor to open the butterfly valve but relies on spring force to lower the choke opening it tends to rev up ok and then wont come down again, and is very alarming when you are driving.
The photos here show a healthy magnet and a furry one, and also show how Vovlo tried to cure this with an aluminium cover on the newer versions.
751907519175192
 

Twinspark

Member
Messages
121
I’m not that well versed on the 3200 but I remmeber in the wheeler dealers mike sent out the TB to this guy who rebuilt them.

Do those have any catch to them? I figured most would just have that mod done to them if it worked so well.
 

davy83

Member
Messages
2,315
Yes they can be rebuilt and the rotary sensors replaced, Maserati Shed still do this (Mike Roberts) who was on the Wheeler dealer episodes. I am doing this now for some reason, and I am also able to convert Volvo units to make newer rebuilt ones or indeed can convert new ones so there are ways to fix it for sure. The magnet assemblies cannot be bought separately, but can be removed from Volvo units ok. The strip down and rebuild is not the simplest process to be honest, but its doable.
 

Mike Maz

Centenary Club
Messages
27
Evening All. Odd problem cropped up today.

3200 has been running beautifully for the few weeks I've had it. Today when I left a meeting the CEL illuminated and the car limped to the next parking lay by.

I reset the throttle upper and lower. Started up, no CEL, but the engine started racing in Park (up to 4,000) and even in drive would idle at 1500 rather than the usual 1000 ish.

Got home. Reset the throttle again and the problem is gone. Any thoughts?
I would recommend getting in touch with davy83 on here. I had the same sort of problem with my throttle body and he sorted me out.
HTH
Mike