F1 Pump (Priming Intervals)

Hey guys,

I was playing around in the boot this weekend while the engine was on and in (N), I could hear my F1 pump making its priming noise every 8.6 seconds, is this normal or too often. I've recently replaced an EV pipe and the Cambiocorsa fluid (CHF).

Are you sure it was 8.6 seconds or maybe it was 8.5 or 8.7 seconds!!
With it not doing any work it should only prime after the pressure as dropped.
Reading the attached from the Maserati tech manuals, with the engine running, in neutral, the pump should not prime within 60 seconds.
As you have just changed the fluid, I don't think it will be anything serious, probably it requires bleeding?

Electric pump
The electric pump brings the oil from the hydraulic reservoir to the operational pressure
for the power unit.
The pump is driven by an electric DC motor and is managed by an ON/OFF control
strategy (the pump does not run continuously). The pump is activated when hydraulic
pressure drops below 40 bar and is switched off when the pressure reaches 50 bar.
When the driver's side door is opened and the ignition key is not inserted, the
transmission control module (NCR) runs the pump briefly to build up hydraulic pressure
before starting the engine.

Solenoid valves internal leakage
Leakage past the spool of the control valve, which is estimated by the NCR and can be
read out by the diagnostic system, constitutes a valuable diagnostic aid in the event of
an electrohydraulic system fault. The value shown is periodically acquired by the NCR
in a self-learning procedure.
Solenoid valve internal leakage in excess of 30 cc/min, combined with problems of
engagement and/or selection, offers an excellent point of reference to understand the
nature of the problem. In this case the solenoid valve must be renewed.
In the case of hydraulic problems use the following procedure in order to isolate the
offending component:

Key ON, Engine Off: the interval time between two pump activations must be no less
than 2 minutes. This makes it possible to check the solenoid valves - accumulator -
electric pump assy.

Key On, Engine running: the interval time between two pump activations must be no
less than 60 seconds. This makes it possible to check the clutch solenoid valve and, by
acquiring the pump restart times, the condition of the accumulator.
The conditions of the electric pump can be assessed by acquisition of its activation
time: an activation ramp with an increasingly gradual slope and activation time in
excess of 5 seconds are clear symptoms of deterioration of the pump.

As the man said. 8.6 seconds is way too frequent.

Pump failing, or excessive leakage

C

It won't take much of a leak to drop 10 bar in 8 seconds. Could well be air as mentioned.

Weren't you the guy that changed his EV1/2 pipe without bleeding the actuator?

8 seconds is far too frequent and will burn your pump out in no time. By running with air in the line you may have damaged the valve associated with the replaced pipe.

Cheers for your responses,

So the pump could be on its way out, this wouldnt be a major issue as it's quite 'easy' to get out now i've removed all my boot linings etc. I replaced my EV5 pipe which had burst and then refilled with the correct spec oil, I did bleed it 5 times to make sure most if not all air was out - I can only do this more to guarentee. The car primes when I unlock it and then again when I open the door, with the engine on and in Neutral it seems to make the same priming noise every 8.6-8.7 seconds (to be honest i think it always has done) so maybe this could be a leaking valve, having looked at Voiceys website and reading the SD read out explanations when it comes to the Cambiocorsa/F1 box, I can see from last year my leak rate was high! but my F1 pump is still going strong so who knows. The test comes when I have it in 1st gear, foot on the Brake - for 2 minutes it should hold and not bite, but i think if there is a valve leak then the clutch is slowly closing even with my foot on the Brake, which then causes a surge before 2 mins.

Okay,

Pressure holds overnight.

Pump runs for 5 secs when door opens.

Pressure holds until engine running in neutral. Problem at this point pump runs every 8 secs.

All gears shift fine. Pump runs every 3 gear shifts.

What part of the system is working with engine running in neutral causing the pump to run ?

Anything I add us a guess. I'd wait for Voicey

C

Hi there,

When you replaced the pipe did you adjust anything else? When I did mine I dislodged the connection to the pressure relief valve which caused the pump to prime constantly - not a pleasant sound when it starts to struggle! There is a thread on here about the mistakes I made....

My currently primes for about 6 secs when I first unlock the door and then every 56 secs when it is idling - bit of a concern as it is under 60 secs but it has not changed in the past 12 months so I am just monitoring it regularly for the moment.

First of all, if you didn't remove the actuator and bleed using the diagnostic then you will have air in the line that you replaced. However, my gut feeling is that this is separate to your current priming issue which is probably down to valve leakage (unless you have damaged EV5 by running air in the line).

As mentioned above, check that the bypass screw is tight before anything else.

The leakage values are estimated by the TCU and apply to all six valves. You really need to have the unit hooked up to the diagnostic to try and narrow it down however the most used (and prone to wear) valves are EVF, EV1 & EV2.

The easiest way to work out which valve is kaput is to replace the valves one by one with known good units. I carry a complete power unit in stock that I know is good so, once the SD3 has given me some clues to make an informed guess, I can quickly switch out the valve to confirm the diagnosis. Quick for me, cheaper for the client.

Hi guys,

Thanks again for your replies, I will check the bypass screw and also the pressure relief valve (are these the same thing?). The car drives fine in all gears it's just the pump I'm worried about, maybe there's still air somewhere I haven't bled like voicey said. Here's my SD printout from before the pipe burst going back quite a few months now.

voicey said:

First of all, if you didn't remove the actuator and bleed using the diagnostic then you will have air in the line that you replaced. However, my gut feeling is that this is separate to your current priming issue which is probably down to valve leakage (unless you have damaged EV5 by running air in the line).

As mentioned above, check that the bypass screw is tight before anything else.

The leakage values are estimated by the TCU and apply to all six valves. You really need to have the unit hooked up to the diagnostic to try and narrow it down however the most used (and prone to wear) valves are EVF, EV1 & EV2.

The easiest way to work out which valve is kaput is to replace the valves one by one with known good units. I carry a complete power unit in stock that I know is good so, once the SD3 has given me some clues to make an informed guess, I can quickly switch out the valve to confirm the diagnosis. Quick for me, cheaper for the client.

Click to expand...

With reference to my previous SD scan and using your website, I can see the Oil Leakage with the Clutch SV triggered is at 4.2 CC/M with the benchmark being 60 CC/M (Excellent), the Oil Leakage with the SV not triggered is 141.6 CC/M with the benchmark being 30 CC/M (Poor). With this in mind it would seem it's been faulty for some time? The pump seems to be coping but obviously it will eventually fail, the split pipe was unrelated to this, also could the 141.6 cc/min leak cause the 8 secs pump duty, a guess it's 19 ml of fluid leaking back through the clutch valve every 8 secs when it should be max 4ml. I've seen the prices for these valves and they are quite scary.

My car has just started to do the same thing. When the car is idling in neutral the pump is priming about every 12 seconds. I have had the car for almost 5 years now and apart from the tie rods, everything has been great, but this year some things have started to go bad. Starting to get tired of it

Aredes said:

My car has just started to do the same thing. When the car is idling in neutral the pump is priming about every 12 seconds. I have had the car for almost 5 years now and apart from the tie rods, everything has been great, but this year some things have started to go bad. Starting to get tired of it

Click to expand...

Hang in there, it's just Italian 'character' manifesting itself in a noticeable way. We've all been there and some of us have never left there!

Oh well, I'll just leave it in storage for the winter and will look into it when spring comes.

Aredes said:

Oh well, I'll just leave it in storage for the winter and will look into it when spring comes.

Click to expand...

Aredes,

Did you ever get to the bottom of your F1 pump priming issue? I have spoken to Mike Roberts from the Shed and he said that it is quite possible that the Accumulator is failing/or has, in my case already failed. These are considered wear items and fail both in the piston form (Maserati) and the bladder form (ferrari, lambo, alfa). Points to note were;
"If the pump runs every few seconds, for a short period of time, and in particular, when the pump starts for the first time in the morning after being overnight if it's only for a few seconds, rather than 10-20 seconds, then it's a failed accumulator."

Explaining that, if there is no pressure charge in the Accumulator piston, then when ever you try to change gear the pressure drops too rapidly and will fail, same goes for the clutch solenoid valve when that is open under pressure to hold the clutch open, the pressure will begin to drop and the pump will need to come in to try and counter the drop in pressure, even when it does charge the pump primes for 3-5 seconds but then after another 8 seconds if primes again - engine on / in neutral without attempting to change gear. The only way to get the car into gear is to pull the lever is rapid succession (2-3 times) - you'll hear the pump prime and then it will knock into gear, this happens all the way up and down (engine off, ignition on).

*PROBLEM SOLVED!*

Installed a new F1 pressure accumulator and clutch solenoid valve into the power unit, priming intervals are now at least 2 minutes when sat in (N) with the engine on, not the 8 seconds as before! In gear (1) with foot on brake, engine on - it is now happy to be sat there for at least 3 minutes without biting the clutch! Whereas previously it would bite then stall the engine! The quick/solid gear changes have returned! Unfortunely as I replaced both the F1 pressure accumulator and CSV at the same time I cannot be 100% certain on which was the ultimate cause, but what I can confirm is that the initial prime when the car is first unlocked (after a day or so of not driving) lasts slightly longer so that maybe indicating the old accumulator was failing due to age (15 years), also my clutch valve leak rates are well over and above the required values. I've now had a lot of time testing some new Mas software which can tell me the clutch wear on the car as well as the PIS setting (not able to change it yet), it can read the gearbox TCU and the Suspension ECU as well as all the usual OBD features.

Do tell regarding the software! Does this include the air bag light resetting?

mjheathcote said:

Do tell regarding the software! Does this include the air bag light resetting?

Click to expand...

Yes, I would be interested in that too, well done by the way, a win for persistence I feel!

Me too! I would love some in depth read (not write to avoid getting in trouble) software