T4 Screenshots Engine Management.
 

Diesel T4 Screenshots

Recently there has been a few posts as regards the live data readings you should see on T4 and also some other diagnostic equipment.

First pic shows the overall view screen:

http://i217.photobucket.com/albums/c...russ42/037.jpg

Note the engine isn't warm and as it warms up the maf reading drops.

http://i217.photobucket.com/albums/c...russ42/045.jpg

You can interrogate any of the reading by clicking on them although if any are out of spec on T4 it highlights the figure with a grey background.

Next we see the maf reading explored:

http://i217.photobucket.com/albums/c...russ42/039.jpg

You can blow this up by clicking again very handy when some distance away when monitoring any figure.

http://i217.photobucket.com/albums/c...russ42/040.jpg

The larger block represents the reading the smaller black block above it is the acceptable range.

Coming out of the overview and entering the Cylinder fuelling screen we can see there's a problem:

http://i217.photobucket.com/albums/c...ss42/003-3.jpg

There's some injector issues here either leakback or dirty/worn/sticking injectors.

Leakback test results:

http://i217.photobucket.com/albums/c...ss42/005-2.jpg

Results after one dose of injector cleaner and a good hard run:

http://i217.photobucket.com/albums/c...russ42/041.jpg

Still some issues here give it another dose of injector cleaner and re-test.
If after that there's still a considerable inbalance the injector overhaul or replacement may be necessary.


Engine roughness screen:

http://i217.photobucket.com/albums/c...russ42/042.jpg

This represents the amount of work each cylinder is doing to maintain the idle speed.

Next we see the effect of the Synergy mafam on the MAF and it's effect on the maf voltage and airflow figures on a perfectly good Bosch maf.

Firstly Mafam off (engine up to temp):

http://i217.photobucket.com/albums/c...ss42/001-1.jpg

Next mafam on low:

http://i217.photobucket.com/albums/c...ss42/002-3.jpg

Notice the incresed airflow figure for such a small amount of voltage increase on the maf.

This can be enough to affect the airflow figures at 3000 revs to outside acceptable levels and cause un-necessary overfuelling.

With the aid of T4 you can use this information to set up the best setting of mafam and tuning to be applied for best performance and economy.



Russ

well done very informative you are the best keep it up


andy :bowdown::bowdown::bowdown::bowdown::bowdown::bowd own::bowdown::bowdown::bowdown::bowdown::bowdown:: bowdown::bowdown::bowdown::bowdown::bowdown::bowdo wn::bowdown::bowdown::bowdown::bowdown::bowdown::b owdown::bowdown::bowdown::bowdown::bowdown::bowdow n::bowdown::bowdown::bowdown::bowdown::bowdown::bo wdown::bowdown::bowdown::bowdown::bowdown::bowdown ::bowdown::bowdown::bowdown::bowdown::bowdown::bow down::bowdown::bowdown::bowdown::bowdown::bowdown: :bowdown::bowdown::bowdown::bowdown::bowdown::bowd own::bowdown::bowdown::bowdown:

Many thanks Russ for a definatve expanation on that area for the T4.

It once again shows the value of using the correct diagnostic equipment. ;)

Hi Russ

Thanks for bringing back some great memories of fault finding (or indeed setting a new car up) with T4, It was a part of the job that I loved and really miss now :(

Again Russ that is fantastic information.

Just hope mine doesnt throw any problems when you plug her in :bowdown:

And knowing how to use it :cool:

http://www.the75andztclub.co.uk/foru...011017a88f.jpg

Pity its so expensive and quite a few who own it don't know/ can't be bothered to use it properly.

Ron

Very informative Russ and does prove that the maf signal calibration is ridiculously sensitive. How they thought any make of maf could produce such an accurate reading reliably over the long term is beyond me. Still this was the early days of common rail injection systems.

You can therefore, imagine just what a wide variation of signal is encountered on out of spec mafs. I can't hope to cater for every maf with a Synergy or mafam without every one being calibrated using a T4 for each & every maf. But since most owners see their mpg improved, I'm satisfied overfuelling to any great extent isn't an issue.

It also explains why the clone and pattern mafs turn out to be poor. I suspect they are just not manufactured to tight enough tolerances so you might be lucky....

Ron

Thanks everyone just thought it may be useful to provide some information that may prove useful.

Ron, I agree the calibration is very sensitive a small difference can have quite dramatic effects.

The maf figures above show that on a good maf when used with the mafam section on low although the maf voltage is within limits the airflow figure is already outside what the airflow figures should be at idle.

The figure should be between 440 to 500 mg/fire at idle with EGR closed.

As you can imagine when revved to 3000 the amplification is multiplied so there can be a fair bit of overfuelling. It can result in there being up to 100mg/fire more than it should at 3000 revs. Correct figures should be between 650 and 720 mg/fire at a steady 3000 revs.

Of course this is only if the mafam is used on a good maf, I've been guilty of this thinking that because of age or mileage my maf was bound to be out of spec, it wasn't when I checked and have found quite a few others owners that have done the same, with the mafam section turned off they've run even better than before.

Of course quite a few maf's aren't in spec and need the amplification of the signal to get them to a more acceptable level. Many owners don't know how far out of sec the maf is of course and a lot of time just play around with the settings a bit and settle for one that seems to give them the greatest amount of power/torque.

When I look at cars on T4 with a Synergy fitted if they are found to give figures outside the normal levels I try and find a setting that gives airflow figures that are as close to the mid-range of the normal levels at both idle and 3000 revs and have found this often gives the best results.

When I next see one with an out of spec maf, I'll take some more pictures to post to show the effects to the voltage/airflow for different settings of both the tuning section and mafam.

Russ

Russ, have you measured one with an egr bypass fitted?
I suspect these alter the airflow and will give different readings.

Ditto with my intake mod mk2?

Also, even with a Pierburgh maf, good results and better economy can be achieved by using the low maf compensation range (settings 1 to 5).

As everybody wants something different its worth trying all the settings and use whichever gives the result you are looking for, regardless of what it says in the instructions.!
Ron