2,5 tdi AKE running rough when warm.

Thanks Crasher, I guess the suction jet pump is the one I call "baffle chamber pump" wich moves fuel internally in the tank. It's definitly running when I power it directly from the battery ( fuse 28) but I will check that up.
It sometime sounds strange, like it's sucking in air ?
Sjordet, yes could definitly be the injectors, but the problem is that with the old injectors, it was a lot worse ! Makes me a bit suspicious actually, because I tested the old injectors just a couple of days ago( Bought a cheap tester at ebay)
and they seems to be all ok. Spraypattern is fine, blowing from all 6 holes and the popoff pressure is around 215 bar/ all 6. So why did the new injectors make it so much better ?
Matkring
Could very well be that the front seal in my pump is goosed, but the old pump acted up exactly the same way, and the pump I,m running now is practically new, Bosch refurbish from Germany.
We are going to Northern Norway soon, and I might add we are not driving the Audi, thanks god!
I'm anxious to see what solution I come up with myself, cause I must admit I,m totally lost here...
Anyway,have a nice trip to Sweden.
I,ve spent hours looking at graphs of boost, timing aso, and nothing, just nothing suspicous to see, also ohmed EVERY wire involved is this game, from ground, from +,and from the ECU to the respective parts involved, and found nothing.
A didn't bother to post about it, but a few days ago I checked the cam-timing for the third time ( I even pulled the camgear on the right side ( cars left) in order to see the slot in the end of the exhaust cam) and the timing was ofcourse spot on.
I put in the "ofcourse" because with a compression of 26 bar sharp on all 6, the camtiming just can't be much out.
Where do I go from here ?
The only "odd" things I have found is- measuring blocks 14-way out. The readings from the IAT sensor is a tiny bit low and the readings from the MAP sensor with engine off is a bit higher than the ECU readings of athmospheric pressure.
Today I checked for air in the fuel again, and it's still sucking in a few airbubbles, BUT, under 2750 rpm- nothing.
Have a feeling that Crasher is pretty close, so when I find the time I will run the engine from a can, placed in the back seat

My suction pump is not working because when i hit 1/4 of tank level my car stops. Maybe I should fix that? I have never thought of that as an issue :-) I had just settled with that one and held the level over. :-) will that one make my fuel delivery limping when the tank level is higher also?

I bow to the far superior knowledge on this thread, but on the Quattro there are two pumps, right? One that lifts the fuel into the fuel system/injection pump on the right hand side, and one that pumps the fuel across the saddle from the left to the right. I thought Crasher was talking about the right hand one. Matkring sounds like he is talking about the left hand one.

Attachment 21506

There is no pump on the old model. Only transfer pump. The newer model has a pump that pumps the fuel from the tank to the engine.

Quote:

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Originally Posted by Matkring

There is no pump on the old model. Only transfer pump. The newer model has a pump that pumps the fuel from the tank to the engine.

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Right, Audi acknowledge this to be a problem late 2001, and I suspect the reason was that their own mechanics couldn't bleed this system !
Whenewer a fuelfilter was replaced, the Audi garages smelled of all kind of suspicious spraycan content, there was also stories of cracked pistons due to easy start..
About my car, with a new filter it's worse than ever !?? And WHERE is it sucking in air ?? I.ve changed the fuelhoses and there is no place exept the fueltank left.
And why was it running so sweet for 10 km ?

Quote:

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Originally Posted by ametlib

Right, Audi acknowledge this to be a problem late 2001, and I suspect the reason was that their own mechanics couldn't bleed this system !
Whenewer a fuelfilter was replaced, the Audi garages smelled of all kind of suspicious spraycan content, there was also stories of cracked pistons due to easy start..
About my car, with a new filter it's worse than ever !?? And WHERE is it sucking in air ?? I.ve changed the fuelhoses and there is no place exept the fueltank left.
And why was it running so sweet for 10 km ?

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An idea (maybe):
Could the connector on top of the fuel filter be defective? The pressure when running an electric pump between the filter and IP would hopefully show diesel leaking there (or elsewhere for that matter). If you are going to try this, only run the electric pump for a few seconds, then off, then on etc. to avoid too much pressure building on the IP.

Thanks ceilidhalfie, as I said, I'm totally lost here and I velcome any input, and your idea is by no means the worst I've seen. I will test it out by just bypassing the valve.
However it's not my first choice at the moment, because the vane pump in the I.P. sets up a pressure of 24 bar, regulated by a pressure valve in the pump.
And 24 bar is when the system works, who knows how high the pressure will go if the return lines are clogged. It will certenly blow the fuel line and the valve.
But I guess you were aiming against air intruding the system ? No, I really don't think it's enough air to make it this sluggish, but can't be certain so I will check it out.
At this point I'm leaning towards fuel starvation, and when I find time I'll run the engine from a can, placed in the rear seat

You have to make sure it is running when the engine is, I have never had the pump fail BUT often see the command signal to the relay fail. The “suction jet pump” is there and is not electric; it works by the action of the electric pump. This pump is CRITICAL to the way the AKE engine functions.

Suction-jet pump: operation

1 - Suction-jet pump (right-side)
2 - Y-connector
3 - Fuel supply pipe
4 - Baffle housing
5 - Fuel supply pipe
6 - Suction-jet pump (left-side)
7 - Fuel pump
8 - Connecting piece

On vehicles with four-wheel drive the fuel tank is divided into a left and a right chamber

A so-called suction-jet pump -item 6- (left-side) is used for delivering the fuel from the left fuel tank chamber to the baffle housing of the fuel delivery unit -item 4- on the right

A second suction-jet pump -item 1- is located in the right fuel tank chamber and serves to improve the fuel delivery in the right fuel tank chamber to the baffle housing of the fuel delivery unit

The suction-jet pumps operate according to the principle of fluid entrainment: a stream of fuel delivered from the fuel pump fitted exclusively for this purpose -item 7- is passed through a nozzle in the suction-jet pumps -item 1- and -item 6-, and is thus accelerated. The accelerated stream of fuel draws off the surrounding fuel and delivers it to the baffle housing of the fuel delivery unit. The right suction-jet pump -item 1- delivers the fuel directly into the baffle housing, the left suction-jet pump -item 6- delivers the fuel via a separate pipe -item 5-

The fuel is distributed from the fuel pump -item 7- to the two suction-jet pumps via the connecting piece -item 8-. At the same time, the connecting piece restricts the pressure in the pipes to the suction jet pumps. Excess fuel is delivered via the Y-connector -item 2- and directly via another pipe -item 3- to the baffle housing

Unlike the system employed for petrol engines, the fuel supply and fuel return pipes to/from the engine are not required for the delivery of fuel to the suction jet pumps. As on vehicles with 6-cylinder engine and front-wheel drive, the injection pump is sufficient to draw off fuel from the baffle housing in the right fuel tank chamber

http://i222.photobucket.com/albums/d...psc05c75ff.jpg

Ok, now we're talking. Should this pump run continuously when engine is running? Will check first thing in the morning :-))

Crasher, as I said you knows your stuff !!!
My understanding of this system was that the ECU would run the baffle chamber pump ONLY when the tank level was low ( probably based upon tank fuel level signal from the cluster) seems like I've been living in darkness here
Dont have the car here, but I'll check this out asap.
The pump is definitly running when I power fuse 28 directly, and the engine doesn,t stop at low fuel level, but the pump makes some funny noises.
In intervals of 3-5 sec it sounds like air is bubbling up ?
Would theese small sucktion jet pumps be powerful enough to add some pressure in the baffle chamber ? ( can make my "running engine from a can" test not worth the effort)
@ Adamss24 , If you,re reading, I would really like to know if fitting Bosio nozzles will mess up the readings in Measuring Blocks 14 ?( as I suspect my injectors have wrong nozzles) and I doubt anyone can answer this better than you