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Matt Stolton · Posted: Thu Aug 05, 2004 4:31 pm Post subject: One for the P4 owners

The only fault left to fix on my P4 project is the 4x4 system itself.

I think, thanks to Tino's P4 manual, that the problem is with the mesh sensor, but I am also worried about the mesh device itself. I'm concerned as it only appears to have a winding resisitance of 0.5 Ohm, which seems very low for a solenoid/magnetic winding.

Basically, when the ignition is started to position 2, you here a single clunk/ping from the back of the gearbox (I presume the cogs are attempting to mesh), the 4x4 light goes out for about 1/4 second, and then reilluminates, and stays on, leaving me in P2 mode.

Before I start spending too much money on new electro magnetic coupling etc, I would like some cheaper things to check first. Also, how easy is it to change the electro coupling, does it just unbolt from the back of the box, or is it a pig of a job, i.e. gearbox out and rebuild??

The other thing i might try is plugging te p4 ECU's test outlet into an Alfa PC, to yield any clues. It has a connection like the T2 tester for the engine ECU, which I presume can be plugged into the appropiate PC and software, and interrogated/reset. Is this correct??
_________________
Regards

Matt

Ex Alfa 33 'GTA' (P4 with Knobs On)
Now cruising in a 166 3.2 Ti!!

tvatavuk · Posted: Fri Aug 06, 2004 9:41 am Post subject:

Hi Matt,

Are you sure that your both brake switches are working and in sync?
You connected all wires Smile

Have you disconected sensor and tried inserting 1.5k Ohm resistor between blue and black wire on L42, to imitate sensor?
Unfortunatly I don't have answers to both of your questions.
3 years ago I tried to plug my 33 on ALFA PC, but that dealer didn't have program for testing 4x4 ECU. I tried Magnetti Marelli mechanic with same result.
Because of that I don't know anything about 4x4 ecu error logging, but I do know that with each turn of ignition key to start, 4x4 ecu boots up, checks all sensors,switches and tries to engage 4x4 if all conditions to engage it are ok.
_________________
Tino Vatavuk
Little black dress which replaced Alfa Romeo 33 S 16v Permanent 4 GMo

raj · Guest

Give me a call at work on saturday ,you can check my p4

Matt Stolton · Posted: Tue Aug 10, 2004 9:18 am Post subject: NIghtmares

Tino - replaced both brake switches, and both are synced perfectly. I'm becoming increasingly certain it is mesh sensor or Electro Magnetic Coupling. I'll keep working on it untill its fixed.

Raj - Long time no hear and all that. Those valve springs worked a treat!! Sorry I didn't call Saturday, had a bad day at work, wasn't able to get 5 minutes. Are you interested in coming to Aces Thursday? I thought you were under instruction from the other half to get a sensible car anyway??
_________________
Regards

Matt

Ex Alfa 33 'GTA' (P4 with Knobs On)
Now cruising in a 166 3.2 Ti!!

raj · Guest

too busy to go ace cafe,maybe next month.On your p4 problem,give me a call .Ive rebuilt my coupling so got loads of info.

agha33 · Guest

Hi, have you checked the wiring of the magnetic coupling and the sensor?

I had the problem that the wiring was faulty. I still have a sensor in spare, but I live in Germany

Matt Stolton · Posted: Sat Aug 14, 2004 2:57 pm Post subject: Cheers all

Raj - I'll give you a call once I have soured a spare EMC, I will check it and rebuild it to put straight onto my box. I had the box rebuilt early on in the project, so I want to retain that, and swap the EMC. Does it bolt off of the back of the box, or is it a gearbox strip down and rebuild sort of nonsense?
I'll be in touch to pick your brain if you don't mind.... Whats the postcode of your garage again, I can't remeber where it was....

Agha33 - I have checked the wiring, which buzzes through OK, and I'm getting 12V to the EMC as the ignition comes on, but it is no longer making the ping noise that it did, so I guess it is seized.
_________________
Regards

Matt

Ex Alfa 33 'GTA' (P4 with Knobs On)
Now cruising in a 166 3.2 Ti!!

raj · Guest

matt the power take off unit can be replaced in situ,a bit tricky but easier than removing gearbox. Cheap to repair if the coil is not damaged,parts should cost no more than 100 pounds.If the coil is damaged cheaper to buy a new unit from alfa .With a bit luck I might be able to help you.
My postcode is E15 2NH ,Garage nos 8519 5610