Selespeed and catalyser issues

Started by SeleMatt, September 01, 2019, 04:18:35 PM

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SeleMatt

1) A week or so ago, my wife was in City mode negotiating a round-a-bout when the car slipped into neutral.

2) Today, I was barrelling up a hill climb in manual mode through a corner in 2nd. When I selected 3rd with the flappy paddle it went straight into 5th. I took it easy from there and coasted down the other side of the hill. I then turned left from a standing start on the flat. While trying to accelerate hard up the straight in 2nd again, the car started to surge/pulse (very evenly/rhythmically) and then when trying to select 3rd with the paddle, it once again went straight into 5th again.

About 10 minutes later, the engine light came on.

I drove the remaining 100km's home in City mode where it performed flawlessly.

I've just scanned the engine and gearbox. Fatal error codes PO420 and 430. I've just recently fitted new cat sensors (all 4 of them) and before purchasing any of them, I'd visually inspected the cats and found them to be perfect (well at least visually and obviously not rattling etc).

Scanning of the gearbox presented no error codes...?...

Happy Fathers Day to all.

bazzbazz

#1
At the back of the engine near the firewall there are two large "Block & Slide" electrical connectors, one black, one purple. the O2 sensors run through these plugs and are notorious for causing issues. Open them up and give a good spray with electrical cleaner and open & close them several times to clean up the pin contacts.

WARNING! - MAKE SURE YOU DISCONNECT THE BATTERY NEGATIVE LEAD FIRST!!

As for the gear changes, me guess, the car tries to go from 3rd to 4th, but hunts & fumbles around for a moment and then says bugger it, its all too hard and jumps into 5th?

The usual cause is a loose Engagement Lever Pin Securing Screw, most commonly (but incorrectly) referred to as the "Pinch Bolt". It's the bolt that connects the gear selector horn that sticks out of the top of the gearbox to the actual Selespeed Actuator.

Carry out a "Engagement Lever Pin Securing Screw diagnosis" with MES and see if it passes/fails. If it fails it is definitely the pinch Bolt being loose. Even if it passes, it can still be the problem, re-torque it anyway.

Be aware, a faulty MAF can also set off the O2 sensor errors, give it a clean with MAF Cleaner, can't hurt, can only do good.
(I did tell you diagnostics was very much a black art . . . . didn't I.)   8)
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

Thank you so much as always Bazz.

Just to be clear, it shifted from 2nd to 5th on two occasions in manual mode and not from 3rd to 5th as you wrote in your response.

I'll report back here with the results of all procedures you've recommended.

The black art of diagnostics indeed... 8)

bazzbazz

Could also be a faulty Gear selection position sensor (One on the back of the Actuator near the driveshaft).
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

...and you recommend replacing that sensor and the one next to it at the same time, given if one goes the other probably won't be far behind...?...the  engagement and position sensors.

Correct?

bazzbazz

Yes, the sensors are simple carbon track potentiometers and do wear out sometimes. Check all the other items first, as they don't cost anything but the sensors aren't cheap usually.
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

So I've only had time to clean the purple connector blocks on the firewall and the MAF sensor thus far. Today I went to downshift from 3rd to 2nd when the box fumbled around and decided to remain in 3rd. From then on, I was unable to select any other gear with the paddles or stick, or to select City mode. I pulled over and was unable to select neutral or reverse. I then shut it down and rebooted it. The gear selection LED said 3 still and from there I was able to select neutral, put the car into City and off we went.
I'm thinking this issue is beyond the engagement pin mechanical adjustment and is a sensor.

I'm bored at an airport waiting for a very delayed flight...🙄

Thoughts?

bazzbazz

On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

#8
MES result was 0C. No error codes.

bazzbazz

On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

The result of the MES scan after executing the engagement pin securing screw diagnosis. Thr result was no error codes and a status of OC..

bazzbazz

The correct no error result should be 00.

Get yourself a new Selespeed sensor and replace the selector sensor at the back of the actuator, that is the usual culprit when it comes to this sort of thing if its not the Pinch Bolt.

Try Arese Spares or Italian Automotive Spares for one.

On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

No worries and thanks. I'll check the pinch bolt first and go from there.

SeleMatt

Okay.

So around every 500 to 1000 k's the engine light comes on with lambda sensor failure P420 430 blah blah blah.

This is since having replaced all 4 02 sensors with new Bosch items and checked that the cats are okay.

Apparently I'm supposed to have carried out an 'adaptive parameter reset' since replacing the sensors, something I wasn't aware of.

I've just looked this up in my MES guide and I can't find such a process to carry out.

Am I missing something here?

bazzbazz

Self Adaptation Reset is TAB "F7 Adjustments" in the Engine ECU Menu.

Have you cleaned the 2 sliding block connectors at the back of the engine up against the firewall? One is purple, the other black.
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au