2004 Coupe CC - Strange throttle issue

[konstan]

Hey all, new 2004 Coupe CC owner here... I am not new to working on cars but new to the Maseratis.
The car has thing issue that when I start it up, it revs up to 6000 rpm and stays there. 9 times out of 10 it would do that, but every once in a while it would behave completely normally.

I replaced the pedal pot, cleared the codes and two codes immediately come back: P1159 and P1189. Both are pedal pot related... What gives?

 

[safrane]

Battery reset.

And or throttle reset

 

[CatmanV2]

Where did you get the info that they are pedal pot? Googling seems to indicate that one is MAF (which could well make unsteady revving) and the other fuel pressure (ditto)

@safrane proposes a sensible approach

C

 

[FIFTY]

Worth checking if the rubber intake boot has any splits in it. I had a vacuum leak in the 4200 which would cause it to stall but my old E46 330i had a badly split intake boot which one day caused the engine to rev to red line while sat at the traffic lights (embarrassing) and then crazy hunting idle

 

[konstan]

The codes for the pedal pot were provided by my handy foxwell obd2 tool... I cross referenced them with a spreadsheet I found somewhere and they seemed to match... Soon as the codes come back I will take a picture.

Intake parts are not cracked. I removed and checked them all over.

Right now, the new pedal pot is installed, no codes, and I did the battery reset and relearn. The car does not rev on its own, BUT now it no longer revs even if I try to. Like its in some sort of limp mode. This is the weirdest car I have ever owned

 

[konstan]

Here's the spreadsheet with P1189; I saved it in my google docs but it's gonna take some doing to find where I got it

 

[konstan]

I decided I next had to look at whats around the ECU. Removing the passenger carpet and metal plate reveals the following. Note the two harnesses and two cheesy on/off switches. One of the harnesses is terminated with a connector. The entire set-up looks a lot like what I saw in the DBWEM module install video, must've been put there by a previous owner. How do I go about troubleshooting this? Try to get rid of it ant put it back to factory setup somehow?

 

[konstan]

Kept following the wires, found the Formula Dynamics module.
Unplugged it, capped the harness with the bypass plug (that was plugged into the other connector, see pic above).
Runs great now. Took it for a spin around the neighborhood. All good for now. But, it's been back and forth before, so, will watch it for a couple of days and report.

 

[philw696]

Good work you can always get there back tracking whatever the vehicle is.
It's all part of grass roots diagnostics.

 

[mjheathcote]

Kept following the wires, found the Formula Dynamics module.
Unplugged it, capped the harness with the bypass plug (that was plugged into the other connector, see pic above).
Runs great now. Took it for a spin around the neighborhood. All good for now. But, it's been back and forth before, so, will watch it for a couple of days and report.

There's quite a few wire splices/taps required into the cars loom for the FD DBW module. I guess if one of these fail strange things could result.
Well done for finding it.