3200 throttle issue driving me nuts

CatmanV2

Member
Messages
48,555
Well you can check for voltage on the output terminals of the ECU. Those also look like they might be transistors / power components on the right of the board, so one of them may be dead and causing the issue.

Looks like you're closing in at last.

C
 

rexpontius

New Member
Messages
15
Also measured at the supply pins (highlighted in the picture), and there is a minimal voltage of 0.17 Volts very briefly, so barely anything.

I also suspect the transistors or power parts, but have too limited knowledge to tell what is what .... And the connectors are so tiny, I am afraid to touch them with a probe.

Cheers Rex
 

CatmanV2

Member
Messages
48,555
I admire your persistence. I think you've nailed it. A decent electronic repair shop could probably sort you out....

C
 

rexpontius

New Member
Messages
15
I am in negotiation with the seller of the 'new' TB I purchased. He also still has the engine ECU as well as Code ECU.
If I can replace those, along with the transponder in the key, the car should work again.

Let's see if I can get a good deal from him.....
 

Contigo

Sponsor
Messages
18,376
Get a virgin throttle body sent off to Mike R or Luuk and that way you know it will be fine and have a guarantee.
 

Tamariini

Junior Member
Messages
102
Hi Contigo,

The voltage I am referring to is the voltage of the Sacer sensor at the throttle body.
It has 3 pins: ground, 5v+ and sensor voltage.

Have not measured the pedal pot yet, but will certainly do so shortly.

Cheers
rex
What was the correct voltage afterall on Sacer unit? i had to dismantle mine due to corrosion of magnet on servomotor (which made it stick..) and now idle is bad and car is "coughing" when pushing throttle fast... i believe that SACER unit magnet is slightly off now, car ran perfectly before i had to take throttle body apart.
 

davy83

Member
Messages
2,809
The electronics are high temperature ceramic hybrids and are not serviceable in any workshop so forget messing with that its not worth it. Ok you are getting into a world of confusion here. First the part number oyu are highlighting tells you more or less nothing about the throttle body, and is not the part number, its the end cap and these are more or less all the same.
The voltage on the Sacer is only useful if you are absolutely sure the voltage you had it set to before replacing the position sensors and it needs to be the same as the one you replaced. If you did not measure the old one there is no "right" voltage it depends on a number of things in the set up. I get the position sensors right by running an airflow map in a flow tunnel and setting it up against an original Maserati outline. There are a number of adjustments in the throttle body both mechanical and electronic. Without any way to see the effects of the things you are messing with its really hard to get it set up right.
As to older cars the only thing i have seen is one time an older car did not like the electronics with the facelift code in it and we tried changing the electronics for one with the older code and that worked, but that was only once. So thats possible but is suspect your throttle body is either not set up right or faulty. The throttle body code is the same for automatics and manuals and the difference in the manual and auto engine mapping is in the ECU not the throttle body
 

davy83

Member
Messages
2,809
I also sell converted Volvo units suitable for the 3200 with complete success so far. And yes there are differences and they need a fair bit of changes to make them drive right but it can be done and works pretty well. As I have stated in the previous message I have an airflow mapping tester so i can map the Volvo unit to match the required response and get them to work that way. Its not a simple conversion.
 

davy83

Member
Messages
2,809
The fact you have the cover off the electronics and have been probing around in there probably means that is now broken. The motor is a voice coil unit and uses an old fashioned analogue feedback drive. So measuring that with a meter is just going to break it. Being a feedback system it will also not apply power to the motor when the position sensors are not right, and you cant read what the processor is reading from these, so no way of knowing if that's the problem?
 

dickygrace

www.richardgracecars.co.uk
Messages
7,309
I also sell converted Volvo units suitable for the 3200 with complete success so far. And yes there are differences and they need a fair bit of changes to make them drive right but it can be done and works pretty well. As I have stated in the previous message I have an airflow mapping tester so i can map the Volvo unit to match the required response and get them to work that way. Its not a simple conversion.
Fitted one to my 3200 and it runs like a dream, fantastic work :)
 

davy83

Member
Messages
2,809
Am I missing half the conversation?

C
oh possibly, sorry, I have a private conversation going on with this guy and just thought some of the interaction might be useful to other owners, I didn't think I had answered any questions that were not above?. The throttle problems are without doubt the ones that get to every owner at some point I suspect.
 

CatmanV2

Member
Messages
48,555
oh possibly, sorry, I have a private conversation going on with this guy and just thought some of the interaction might be useful to other owners, I didn't think I had answered any questions that were not above?. The throttle problems are without doubt the ones that get to every owner at some point I suspect.

Maybe, just looks to me like you're talking to yourself :)

C