Hi there,

a bit off topic, but anyways here goes, maybe someone knows something about these numbers that appear in the PP2000 parameter 1 readout. I've been informed that injector number 4 is in quite a bad condition, due to the high value in the 'injector flow correction 4' row - what do these numbers mean? What do we want to see for injector flow correction values? zeroes sounds like most natural value since we are talking about somekind of correction :idea:

These are taken at idle, if I load the engine, value for injector flow correction 4 lowers, even down to 0.



Thanx.

Hi there! There are very accurate sensors that measure the vibrations caused by the fuel exploding in the cylinders one at a time. Based on this and more data, the ECU calculates the correction to apply to every injector (4 injectors, 4 cylinders). The correction is calculated in mm^3/stroke, because it is the correction to the IQ - Injected quantity (called injected flow set point in that picture), that is the amount of fuel each injector squeezes in the combustion chamber at every cycle.

So if the |correction| is very big that means the injector has something bad, a value above 2 already is a hint, above 3 a proof, 4 is a certainty. Injectors should be removed (this can be a pain - I speak from experience) and cleaned professionally (with ultrasonic waves), or worn parts replaced. This is expensive. At least 60€/injector.

In your case if the corrections go to 0 at load that's a good thing. However it'd be nice to have a video of this during various stages of driving, that is as if you were driving normally. To do this grab a program that records the screen (like Autoscreenrecorder Free) and start it up, then go for a short trip.

Also specify if this happens from cold or hot more frequently, and if your revs go up and down..

My corrections too are very big (~4 numbers) just after I turn the engine on, then after a couple of seconds it settles down to ~1. Also strange, you have a very low idle. Mine idles at 750rpms without AC and 803 with AC on. I prefer a higher idle because the oil pump comes into play earlier, but that's not a huge difference. That can be changed via a remap by the way.

Run the car at 2000 RPM. If there is still such big IQ correction then injectors 4 and 3 need service.

Thanks for explaining the numbers :)

I'll take a ride tomorrow and make a video of these params at different RPMs.

At time of the screenshot AC was off.

Here are the videos.

I added some diesel injector cleaning fluid two days ago and drove about 300 km, 1/3 tank, at the time these videos were taken. I don't believe it had worked its magic (so far)..

city - at idle values are the as before in original post, when load increases injector 4 correction lowers


city - interesting stuff with piston 3 - what is going on?

.. some road driving next ..

road, 100 km/h - 4th or 5th gear, interesting math: add up all injector flow corrections and you get 0


road, 150 km/h - 5th gear, as soon I enabled tempo at ~150 km/h the injector correction values froze until I either decelerated and then accelerated again, or changed gears. I'm pretty sure these are not correct values for these RPMs as they usually change non-stop. All other values were refreshed. I guess tempo does something to the ECU or my diag tool got confused for a while there.. I had no problem repeating the issue.

.. a bit of accelerating ..

road - up to 4000 RPMs, shouldn't my third piston be active more early? Need to get that RPMs where it deactivates next time ..

Injector 3 is the worst of all. Injector 4 also needs to be look at the service.
Third piston in the pump is deactivated by rail pressure and not by rpm.

hinkxx wrote:.. a bit of accelerating ..

road - up to 4000 RPMs, shouldn't my third piston be active more early? Need to get that RPMs where it deactivates next time ..

accel-driving-road-150-param2s.avi

Injector three needs attention, the others are fine more or less. Third piston deactivation refers to the third piston in the HP pump, not the third engine cylinder, and as RPM Freak says it is controlled by the pressure sensor.

Do not use injectors cleaner like they were all the same. There are huge differences.
Avoid the normal stuff in small, 250ml or 325ml plastic bottles. Go for the professional stuff in half a liter or liter bottle, and put it in when you have 10-15 liters left in the tank (following the product usage instructions on the package).
I had serious injectors problem (the car run on 3 cyls most of the time). None of all those crap injectors cleaned solved it, I then used the professional stuff the local injector specialist uses, a half a liter can from Greenstar (same as some professional products from Wynn's). It worked it's wonders and although I still had to get my injectors cleaned for the many months to come the car was always running ok, much better than before, and I had no problems of it running on 3 cylinders anymore.
Bluechem also does some good stuff of which I cannot remember the name.

EDIT: before buying look at the components of the cleaner, the ones that come in small plastic bottles are mainly 99% kerosene, they don't help much.

OdinEidolon wrote:

hinkxx wrote:.. a bit of accelerating ..

road - up to 4000 RPMs, shouldn't my third piston be active more early? Need to get that RPMs where it deactivates next time ..

accel-driving-road-150-param2s.avi

Injector three needs attention, the others are fine more or less. Third piston deactivation refers to the third piston in the HP pump, not the third engine cylinder, and as RPM Freak says it is controlled by the pressure sensor.

Thank you both for confirming problems with 3 & 4.

Silly of me for thinking that it was engines third piston :oops:

OdinEidolon wrote:Do not use injectors cleaner like they were all the same. There are huge differences.
Avoid the normal stuff in small, 250ml or 325ml plastic bottles. Go for the professional stuff in half a liter or liter bottle, and put it in when you have 10-15 liters left in the tank (following the product usage instructions on the package).
I had serious injectors problem (the car run on 3 cyls most of the time). None of all those crap injectors cleaned solved it, I then used the professional stuff the local injector specialist uses, a half a liter can from Greenstar (same as some professional products from Wynn's). It worked it's wonders and although I still had to get my injectors cleaned for the many months to come the car was always running ok, much better than before, and I had no problems of it running on 3 cylinders anymore.
Bluechem also does some good stuff of which I cannot remember the name.

EDIT: before buying look at the components of the cleaner, the ones that come in small plastic bottles are mainly 99% kerosene, they don't help much.

Darn, just got the one that fits both cons: small and with kerosene :roll: