Messages

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 10 May 2024, 11:33:25 PM »

Long thread here:

https://www.saabcentral.com/threads/p0089-code-2-8l-v6-any-experience.188411/page-7?nested_view=1&sortby=oldest

Some insight, some rubbish, especially when people confuse the MAP sensor with the fuel pressure sensor

I already looked for Insignia errors. They exist, but little useful information.

The above thread indicates that the parts from a 2WD fuel pump can be fitted to a AWD pump, if the AWD pump is not available, oh and a lot seem to fail at the 65-70k mark.

Other than that I think your list of possibilities is fair. I used to think a couple of hunderd quid for a fuel pump swap was expensive...

Oh and are you using standard E10 or premium E5 like V-Power

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Off-topic chat, Help, Advice, General motoring issues / Re: What I Did To My Saab Today.

« on: 10 May 2024, 10:03:10 PM »

Good news on the MOT, another year of life extension.

I suggest you get some Bilt Hamber Hydrate 80 & apply that to the rusty areas. Following Will's recommendation there was a phase where this was pretty much a pre-MOT exercise, but now the chassis side hardly ever needs work on my cars.

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 10 May 2024, 09:24:30 PM »

Perhaps of some use, especially when a workshop posts a query:

https://www.saablink.net/threads/fuel-pump-and-p0089-2008-v-6.120981/

https://www.saablink.net/threads/9-3ss-v6-fuel-press-reg-performance-p0089.47822/

I haven't found any details of the relevance of the modes, but the injectors are rated at 360ml / minute so 2.16 litres / minute

They obviously operate on duty cycle so I suspect the operating modes up the basic flow rate, stepwise, which is then fine tuned by Motronic to meet engine requirement via duty cycle,

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 10 May 2024, 06:42:43 PM »

That's quite useful:

Are the dips in fuel pressure single data points, or are there a number of data points at those low pressures

This could be "correct" if the fuel pump had been instructed to move into mode 1 or mode 2, but we don't know enough about the purpose of the different operating modes.

A comparison between PWM and fuel pressure should be quite instructive. I would even go so far as to calculate a ratio for each data point and graph that. I suspect, like you, that fuel pressure is dropping when PWM is not giving the instruction

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 10 May 2024, 12:36:41 PM »

Thoughts:

The tank pump has a delivery capacity stated of 0.83litres per 30 seconds at 5 bar "back pressure". So, not far away from the 2 litres / minute I mentioned earlier. You can confirm this

How does fuel get from the left side of the tank to the pump side - there is talk about an extra delivery line. It looks like a line pumps fuel into the left hand part, which then uses a venturi effect to suck fuel from the laft to deliver to the right hand side. What happens if the venturi port becomes occasionally obstructed

If the tank pump is providing the pressure for the injector (and is not a lift pump with a high pressure pump at the engine side), then the risk is that what is created/attempted in the tank is not what is seen by the pressure sensor

Looking at the error code, reference is made to it being triggered by a + / - 25% change in the PWM signal for more than 5 seconds

On the basis that fuel demand does not really change at idle, I would log that PWM signal. You may find the error is correct, or that something undocumented must be throwing it, in which case, diagnosis is going to be harder

Those 10 operating modes for the fuel pump module are nagging away at the back of my mind, perhaps something is happening when switching modes. I believe the control module itself is under the back seat ?

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 09 May 2024, 10:42:39 PM »

I think this is one occasion when less is more

May I suggest reducing the inputs to

Engine rpm
Fuel pressure
Fuel level (litres not gallons, I assume a full tank is 61 litres)

Looking at the data it seems that the engine started cold, with fast idle, the idle dropping down to sub 700 rpm when warm. At that point, the fuel pressure was around 2.7 bar and the engine was producing about 7bhp

If you look at time index 70903.74163, you can see that fuel pressure had dropped to 249 kPa. Below 2.5 bar. I wonder if that is the trigger. Also, why is the fuel pressure dropping to 2.49 bar at 740 rpm when you later need 2.73 bar at 71116.56063 for 695 rpm. Then right at the end of the file the pressure drops to 2.28 bar. Is that lower level the trigger for the code ?

How does the injection work on these cars. I'm assuming that the common rail has a pressure determined by the pump and therefore the duty cycle of the injector is pretty much fixed, with pressure increase determining a greater quantity of fuel to be injected. Then, once a maximum quantity for the duty cycle is achieved then perhaps the duty cycle will be extended. . As opposed to the B235 etc design where the pressure is fixed and the duty cycle varies to deliver different amounts of fuel

I would try to identify the symbol for the operating mode of the high pressure pump so you can compare to values in WIS

Does the ECU store a snapshot of the operating parameters when a code is triggered. The NG9-5 does, but that's GM GDS2 rather than Tech II

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 08 May 2024, 06:33:15 PM »

Looking at the first tranche of data more closely, as engine speed really only 694 rpm, with 33% load

What are the corresponding equivalents

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 06 May 2024, 06:34:48 PM »

Moving to SI usints is usually a recipe for confusion so I'll speak automotive 

The test protocol in WIS talks about using Tech II to activate different modes, with a low of 1.9 bar, then in ranges typically from 2.3-2.6 bar all the way up to 2.9-4.9 bar

Thinking about the B2x5 engines they operate at 3 bar, without adjustment for boost, so it is reasonable to expect that the later cars should be capable of a flow at least equivalent to thar derived for the 3 bar pressure, though perhaps less because there is, as you said, no fuel return.  2 litres / minute flow is also a handy test value for cars of this sort of power.

If you don't have the test gear (and why should you), then perhaps you can run a flow test, which may also illustrate a restriction in the pipe ?

As you suggest, 2 bar pressure does seem low, can you perhaps use Tech II to do an internal measure on the different operating modes ?

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New Saab 9-5 (2010 on) / Re: 9-5 NG Rescue project

« on: 06 May 2024, 06:24:37 PM »

I have had at least two sets delaminate on OG 9-5's - on road cars I have tended to use Pagid (Mintex)

On the NG 9-5's this car arrived with one delaminated, and to get me through the MOT just chucked in one of the spares from the petrol NG. The disc was a little damaged already, because of the failure, so perhaps it was more grabby than usual, but not enough to show on the rollers.

I one tried EBC Greenstuff as an alternative to Mintex M144 (yes, that long ago). They were not as good, suffered from fade and apparently caused terror in the EBC technical department when they got to hear the application I had tried them on....

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New Saab 9-5 (2010 on) / Re: 9-5 NG Rescue project

« on: 06 May 2024, 05:28:04 PM »

A few more jobs done:

One of the pads (OSR outside) had delaminated meaning these was much scraping of backing plate against disc - this is becoming a recurring problem on pads recently, I suspect "better for the environment" adhesives as this never used to happen.

I put new Brembo discs & pads on and a partial fill with V-Power and saw a significant rise in mpg, now up to 45 rather than the 40 I got on the trip home on Thursday. I'll put the standard diesel in tomorrow to see if it's the fuel or just the friction reduction that's brought the benefit

It seems that over the past few weeks the car has decided it can get 580+ miles out of a tank of diesel, so the internal calculator seems to be working correctly once again. Unless of course, this is down to different levels from the two sensors, one being used for the fuel gauge, the combined being used for DTE, and the one used for the fuel gauge has lost it's stickyness 

Replaced the drivebelt idler pulley, at a cost of £13. However, because I was in a rush I reassembled without testing the tensioner pulley. The noise remains, so I guess that is next. As this is going to be the original, I think i will just replace the whole assembly, rather than go for the pulley only.

Though not on this car yet, I have been doing a lightbar repair on the petrol NG. I added to the handy thread on UKS, but 40 replacement LED's cost less than £3 and a fiver for a voltage regulated power supply, which to this point has been for testing purposes only

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 06 May 2024, 05:15:42 PM »

This is going to be a difficult one, as there are two modes of failure and having simulated the diagnostic methodology in WIS will likely take you to "The fault still exists"

12

Off-topic chat, Help, Advice, General motoring issues / Re: Non Saab jobs - satisfaction

« on: 02 May 2024, 10:21:02 PM »

Little victories are important

You don't need reversing sensors or snazzy paintwork for the MOT. I would be tempted to put it in to get the ticket, or at least so you know what other more significant jobs you need to do. I used to get cross with the local Saab dealer for doing a service on the car before they did the MOT. "what if it fails.... I have a freshly serviced car that I can't use?"

13

Off-topic chat, Help, Advice, General motoring issues / Re: What I Did To My Saab Today.

« on: 27 April 2024, 02:00:47 PM »

Took the black 2006 Dame Edna for an MOT

The tester remarked that I did a lot of miles in her, as he checked the MOT history. Then he gave me a clean ticket 

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Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 26 April 2024, 06:04:09 PM »

Now you will never know what solved the problem....

15

Saab 9-3 Sport Saloon / Convertible / Combi (Wagon/Estate) / Turbo X / AWD (2003 on) / Re: 93 V6 fuel pressure release.

« on: 24 April 2024, 06:47:52 PM »

Funny.... having seen the agricultural engineering approaches to ripping open a hole in the 9-3 floor to get access to change the pump, I was wondering "what about getting a 9-5 cover plate (perhaps with part of the 9-5 floor) and spending the money on doing what Saab should have done in the first place".

Or you could just put a 20 ohm resistor in series