Author Topic: Alfa 147 negative Selespeed pressure reading (can't change gear, etc.)  (Read 837 times)

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Hello everyone,

I know there are thousands of Selespeed threads across the various Alfa forums, but I have come up against a problem that I haven't found discussed anywhere to date. I have a 2004 147 which is currently out of action as it is currently stuck in neutral. I have a reasonable understanding of the various components of the Selespeed system, and in the not too distant past changed the accumulator, as the car was dropping into neutral when changing gears. So that problem is all solved, and the car has a reasonably new accumulator.

Since then, a new problem developed, in that the car would sometimes get stuck in a particular gear, and sometimes not be able to change out of neutral. When this came up, I was able to diagnose the issue fairly easily, as the Selespeed pump motor was sometimes just not running when it ought to have been. So I removed the pump and its motor from the car, hoping it would just be a matter of changing the brushes. The inside of the motor was pretty stuffed, and it pretty quickly became clear that the whole motor would need replacing.

In hindsight, this may not have been a good idea, but I ordered a new pump motor without the pump to save money. Now, having reassembled the pump, attached it to my new motor, and installed it in the car, all I get is extremely low pressure readings, and I am still unable to change gear. Initially, the readings I was getting were around 10 bar (rather than the 50-55 or so bar required). I have had a go at taking it apart and putting it back together again, but I can't figure out what is wrong, and on the most recent reassembly I am getting readings consistently in the negative. Having done a reading just now, it read approximately -2.5 bar.

I can hear the motor running when starting the car, but it runs for an extremely long time. Since I know the pump motor works, it leaves me wondering whether there is a problem with the pump itself caused by me fiddling with it, since before all this the car would work fine when the motor would run. I should add that I have checked, and it the pump does pump fluid when connected directly to a battery, but I can't say whether it is pumping with enough pressure or not.

I would be extremely grateful for everyone's thoughts and any possible pointers as to what to do next.




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Re: Alfa 147 negative Selespeed pressure reading (can't change gear, etc.)
« Reply #1 on: September 13, 2021, 08:41:21 PM »
I think you have answered you own question, you're just looking for someone to confirm what you already know.  ;)

You really need to buy a complete new pump, or purchase a reconditioned item from someone who does them professionally.

People don't realize that it's not just the brushes in these things that fail, but sometimes the pump section can actually fail too. Also, in my experience swapping pump sections between pumps never works, it just doesn't, and I have reconditioned a LOT of pumps.

If you want a complete new pump try these places -

Arese Spares - Sydney - 0411123640
Italian Automotive Spares - Melbourne -  03 9036 1606

Or, if your in no hurry, you can try the usual overseas suppliers.
2004 Alfa 156 2.0 JTS Sportwagon (Patty)


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Re: Alfa 147 negative Selespeed pressure reading (can't change gear, etc.)
« Reply #2 on: September 16, 2021, 10:03:56 AM »
Thanks. Yes, you are right, I just wanted to double check a couple of things to make sure. The last thing I wanted was to the spend the ~$700 or so on the new motor/pump, only to find out that the problem was elsewhere.

My Alfa has been in a hail storm and then crashed, and has a couple of different coloured panels. So it has pretty much nil resale value, which is why I was being a little stingy in the first place. My main concern at this stage is that it runs, and that keeping it limping along costs me less than replacing it. But I doubt I'll get anything as fun to drive or with a Bose stereo for as cheap as I picked it up in the first place.

Anyway, that said, I reckon I will make contact with Arese Spares. That is where I got the accumulator from last year. Given my Selespeed setup is still pretty much dismantled, it really should only be a 10 minute job to make sure it is all working when I have the right parts to hand.